JP6171812B2 - Electrochromic display element, electrochromic dimming lens, display device, information device, and method for manufacturing electrochromic display element - Google Patents

Description

  The present invention relates to an electrochromic display element, an electrochromic light control lens, a display device, an information device, and a method for manufacturing an electrochromic display element.

  In recent years, so-called electronic paper has been actively developed as an information medium replacing paper. As a display element used for electronic paper, a display element using a reflective liquid crystal, a display element using electrophoresis, a display element using toner migration, a display element using an electrochromic compound (electrochromic display element), Etc.

  The electrochromic display element is a promising candidate for the next generation display element because of its memory effect and being able to be driven at a low voltage. Currently, from electrochromic display element to material design to device design. A wide range of research and development is underway.

  The electrochromism phenomenon is a reversible phenomenon in which, when a voltage is applied to an electrochromic compound, the compound causes an oxidation-reduction reaction to develop or decolor. The electrochromic display element can develop various kinds of colors by changing the structure of the compound and utilizing the electrochromism phenomenon. For this reason, the electrochromic display element is also expected as a display element capable of multicolor display.

  For example, Patent Document 1 discloses an electrochromic element having an organic electrochromic layer in which a plurality of polymer fine particle layers are stacked.

  Patent Document 2 discloses a multicolor display element having a display layer formed by laminating or mixing a plurality of electrochromic compositions that develop different colors.

  Patent Document 3 discloses an electrochromic display device provided with a plurality of electrochromic layers corresponding to a plurality of display electrodes.

  On the other hand, Patent Document 4 uses a TFT (thin film transistor) as a drive element to realize a practical electronic paper using an electrochromic display element, and on a pixel electrode (counter electrode) on which a plurality of TFTs are separately formed. Disclosed is an electrochromic display device that has excellent display quality and excellent durability without color bleeding, image blur, etc., by forming a charge retention layer (high resistance layer) as a continuous layer (solid film). Yes.

  In addition to the above-described electronic paper, electrochromic display elements are also being considered for application to light control lenses, light control windows, anti-glare mirrors, and the like. For example, an electrochromic dimming lens that can be reduced in thickness, weight and cost by forming a dimming function unit in which a thin film is laminated on a single lens and has excellent productivity has been proposed. .

  By the way, an electrochromic display element used for electronic paper, a light control lens, or the like is desired to have excellent light resistance in reflective display and transmissive display. In addition, in the reflective display, it is desired to have a white reflectance comparable to that of paper.

  Conventionally, titanium oxide has been suitably used in electrochromic display elements. In particular, in the reflective display, by using titanium oxide nanoparticles as the electrochromic compound-supporting particles, and by using titanium oxide particles having a high white scattering property as the material of the white reflective layer, the electrochromic display element is High white reflectance and high contrast ratio can be maintained.

  However, titanium oxide, which is a photocatalytically active substance, decomposes the electrochromic compound and other constituent elements, thereby reducing the light resistance of the electrochromic display element. As a countermeasure for suppressing the photocatalytic activity of titanium oxide, it has been proposed to use rutile type titanium oxide, but it is difficult to improve the decrease in light resistance.

  In Patent Document 5, in order to suppress the photocatalytic activity of titanium oxide particles used as a material for the white reflective layer, the surface of the titanium oxide particles is coated with a polymer compound that is inert to the display medium composition. However, the coating with the polymer compound cannot sufficiently suppress the photocatalytic activity of the titanium oxide particles. Furthermore, there is also a problem that measures for suppressing the photocatalytic activity are not taken for the titanium oxide nanoparticles used as the electrochromic compound-supported particles.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide an electrochromic display element, a display device, and an information device that are excellent in light resistance in a reflective display and a transmissive display. Moreover, it aims at providing the electrochromic light control lens excellent in light resistance.

  In order to achieve the above object, an electrochromic display element according to the present embodiment includes a display substrate, a display electrode, an electrochromic layer provided in contact with the display electrode, and a facing provided facing the display substrate. The surface of the titanium oxide particles contained in the electrochromic layer has a substrate, a counter electrode, a charge retention layer provided in contact with the counter electrode, and an electrolyte layer filling the space between the display substrate and the counter substrate. It is characterized by being coated with a metal hydroxide.

  The electrochromic light control lens of the present embodiment includes a lens, a first electrode layer provided in contact with the lens, and an electrochromic layer (deterioration prevention layer) provided in contact with the first electrode layer. An insulating porous layer provided in contact with the electrochromic layer (deterioration preventing layer), a deterioration preventing layer (electrochromic layer) provided in contact with the insulating porous layer, and a deterioration preventing layer (electrochromic layer) The second electrode layer provided in contact with the layer), the space between the first electrode layer and the second electrode layer, and contact with the electrochromic layer and the deterioration preventing layer through the insulating porous layer The surface of the titanium oxide particles contained in the electrochromic layer is coated with a metal hydroxide.

  According to this embodiment, it is possible to provide an electrochromic display element, a display device, and an information device that are excellent in light resistance in reflective display and transmissive display. Moreover, the electrochromic light control lens excellent in light resistance can be provided.

2 is a diagram illustrating an example of a structure of an electrochromic display element according to Embodiment 1. FIG. 2 is a diagram illustrating an example of a structure of an electrochromic display element according to Embodiment 1. FIG. 2 is a diagram illustrating an example of a structure of an electrochromic display element according to Embodiment 1. FIG. 6 is a diagram illustrating an example of a method for manufacturing an electrochromic display element according to Embodiment 1. FIG. 6 is a view for explaining light resistance of an electrochromic display element according to Embodiment 2. FIG. It is an example of the structure of the information equipment which concerns on Embodiment 3. 6 is a diagram illustrating an example of an electrochromic light control lens according to Embodiment 4. FIG. It is a figure which shows an example of the structure of the spectacles using the electrochromic light control lens which concerns on Embodiment 4. FIG. 10 is a diagram for explaining light resistance of an electrochromic light control lens according to Embodiment 5.

(Embodiment 1)
(Structure of electrochromic display element)
FIG. 1 shows an example of the structure of the electrochromic display element 20 according to this embodiment.

  The electrochromic display element 20 includes a display substrate 21, a first display electrode 22, a first electrochromic layer 23, a first insulating layer 24, a second display electrode 25, a second electrochromic layer 26, a second electrochromic display element 20. An insulating layer 27, a third display electrode 28, a third electrochromic layer 29, an electrolyte layer 30, a white reflective layer 31, a charge holding layer 32, a counter electrode 33, a driving element layer 34, a counter substrate 35, and a wall member 36 Including.

  As shown in FIG. 1, the electrochromic display element 20 has a white reflective layer and a plurality of electrochromic layers between two opposing substrates, and the space between the substrates is filled with an electrolyte layer 30. Yes. Although not clearly shown in FIG. 1, the titanium oxide nanoparticles contained in the electrochromic layer and the titanium oxide particles contained in the white reflective layer are coated with a metal hydroxide.

  As a detailed structure on the display substrate 21 side, a first display electrode 22 is provided in contact with the display substrate 21. Further, a first electrochromic layer 23 is provided in contact with the first display electrode 22. Further, a first insulating layer 24 is provided between the first electrochromic layer 23 and the second display electrode 25. Further, a second electrochromic layer 26 is provided in contact with the second display electrode 25. Further, a second insulating layer 27 is provided between the second electrochromic layer 26 and the third display electrode 28. Further, a third electrochromic layer 29 is provided in contact with the third display electrode 28.

  On the other hand, as a detailed structure on the counter substrate 35 side, a drive element layer 34 is provided in contact with the counter substrate 35. Further, a counter electrode 33 is provided in contact with the drive element layer 34. The counter electrode 33 is provided corresponding to each drive element included in the drive element layer 34. Further, a charge retention layer 32 is provided in contact with the counter electrode 33.

  The white reflective layer 31 may be formed in contact with the third electrochromic layer 29, or may be formed in contact with the charge retention layer 32.

  The display substrate 21 includes a first display electrode 22, a first electrochromic layer 23, a first insulating layer 24, a second display electrode 25, a second electrochromic layer 26, a second insulating layer 27, a third The display electrode 28, the third electrochromic layer 29, and the like are used for supporting a laminated structure.

  The material of the display substrate 21 is preferably a light transmissive material. For example, glass, a plastic film, etc. are mentioned.

  The first display electrode 22 causes the first electrochromic layer 23 to be colored or decolored by a voltage generated between the electrode and the counter electrode 33. The second display electrode 25 develops or decolors the second electrochromic layer 26 by a voltage generated between the electrode and the counter electrode 33. The third display electrode 28 develops or decolors the third electrochromic layer 29 by a voltage generated between the electrode and the counter electrode 33. Since the color development in each electrochromic layer is determined by the magnitude of these voltages generated between the counter electrode 33 and each display electrode, the color tone of each electrochromic layer changes depending on the voltage.

The material of the first display electrode 22, the second display electrode 25, and the third display electrode is preferably a light-transmitting conductive material. Examples thereof include inorganic materials such as indium oxide (ITO) doped with tin, tin oxide (FTO) doped with fluorine, and tin oxide (ATO) doped with antimony. Further, it is particularly preferable to use InSnO, GaZnO, SnO, In ₂ O ₃ , ZnO or the like.

  The first electrochromic layer 23 includes an electrochromic compound 23a, a metal oxide (titanium oxide) nanoparticle 23b supporting the electrochromic compound, and a metal hydroxide 23c covering the surface of the metal oxide nanoparticle 23b. Included (see FIG. 2). As shown in FIG. 2, by adsorbing a single molecule of the electrochromic compound 23a to the metal oxide nanoparticle 23b, the large surface area of the metal oxide 23b nanoparticle can be used to efficiently form the electrochromic compound 23a. Electrons can be injected. Therefore, the color density of the electrochromic compound 23a during color development can be increased, and the switching speed between color development and decoloration can be increased.

  The electrochromic compound 23a generates an oxidation-reduction reaction by the voltage generated between the first display electrode 22 and the counter electrode 33, and develops or decolors (reversible reaction). The length of the single molecule of the electrochromic compound 23a is preferably about 5 nm or less.

  The metal oxide nanoparticles 23b carry an electrochromic compound 23a. The particle size of the metal oxide nanoparticles 23b is preferably about 5 nm to 100 nm, and more preferably about 20 nm. By setting the particle diameter of the metal oxide nanoparticles 23b to about 5 nm to 100 nm, the first electrochromic layer 23 can be made a transparent layer. That is, in the reflective display element, a high white reflectance can be obtained when no color is generated. In the transmissive display element, a vivid color is obtained at the time of color development, and a colorless and transparent state is obtained at the time of decoloration.

  The metal hydroxide 23c covers the surface of the titanium oxide nanoparticles and suppresses the photocatalytic activity of the titanium oxide. The film thickness of the metal hydroxide 23c is preferably 0.2 nm or more and 4.0 nm or less. The metal hydroxide 23c is the reason for suppressing the photocatalytic activity of titanium oxide. By coating the surface of the titanium oxide nanoparticles with the metal hydroxide, the titanium oxide nanoparticles and the metal hydroxide This is considered to be because free radicals generated at the interface can be deactivated (inactivated). As a result of suppressing the photocatalytic activity of titanium oxide, it is suggested by the experimental results described later that the light resistance of the electrochromic display element can be improved.

  In FIG. 1, the metal oxide nanoparticles 23b have a structure supporting one type of electrochromic compound 23a, but the metal oxide nanoparticles 23b support a plurality of types of electrochromic compounds. It is also possible to do.

  Similarly to the first electrochromic layer 23, the second electrochromic layer 26 and the third electrochromic layer 29 are composed of an electrochromic compound, a titanium oxide nanoparticle carrying an electrochromic compound, and a titanium oxide nanoparticle. Includes metal hydroxide coating the surface.

  By covering the surfaces of the titanium oxide nanoparticles contained in the second electrochromic layer 26 and the third electrochromic layer 29 with a metal hydroxide, the photocatalytic activity of the titanium oxide can be suppressed. Therefore, the light resistance of the electrochromic display element can be improved by covering the surfaces of the titanium oxide nanoparticles contained in the electrochromic layer with metal hydroxide and suppressing the photocatalytic activity of the titanium oxide.

  2 shows a structure in which a single molecule of the electrochromic compound 23a is adsorbed to the metal oxide nanoparticles 23b as an ideal state, but the structure is not limited thereto. Any structure may be used as long as the electrochromic compound 23a is fixed at a high density so as not to move. In addition, as long as the electrical connection between the first electrochromic layer 23 and the first display electrode 22 is ensured so as not to hinder the transfer of electrons accompanying the redox reaction of the electrochromic compound 23a. good. The electrochromic compound 23a and the metal oxide nanoparticles 23b may be mixed to form a single layer. The same applies to the second electrochromic layer 26 and the third electrochromic layer 29.

  In this specification, titanium oxide is used as the metal oxide material. This is because titanium oxide is suitably used as a material for the electrochromic compound-supported particles and the white reflective layer, and is currently widely used as a typical photocatalytic active substance. However, the metal oxide material is not limited to titanium oxide. In the future, when a photocatalytically active material that can be applied to an electrochromic display element and whose particles are coated with a metal hydroxide to improve light resistance is put to practical use, such a material is also included in the category.

  The material of the metal hydroxide is not particularly limited as long as the suppression of the photocatalytic activity of the titanium oxide nanoparticles can be effectively enhanced, and examples thereof include iron hydroxide and aluminum hydroxide. It is particularly preferable to use aluminum hydroxide.

  As a material of the electrochromic compound, a known electrochromic compound material such as a dye system, a polymer system, a metal complex system, or a metal oxide system can be used.

  For example, as dye-based and polymer-based electrochromic compounds, azobenzene, anthraquinone, diarylethene, dihydroprene, dipyridine, styryl, styryl spiropyran, spirooxazine, spirothiopyran, thioindigo, tetrathiafulvalene , Terephthalic acid, triphenylmethane, triphenylamine, naphthopyran, viologen, pyrazoline, phenazine, phenylenediamine, phenoxazine, phenothiazine, phthalocyanine, fluoran, fulgide, benzopyran, Examples thereof include low molecular organic electrochromic compounds such as metallocenes, and conductive polymer compounds such as polyaniline and polythiophene. Further, these materials include viologen compounds (see, for example, Japanese Patent No. 39555641, Japanese Patent Application Laid-Open No. 2007-171781) or dipyridine compounds (see, for example, Japanese Patent Application Laid-Open No. 2007-171781, Japanese Patent Application Laid-Open No. 2008-116718). ) Is preferably included. By including a viologen-based compound or a dipyridine-based compound, even when the voltage applied to the display electrode and the counter electrode is low, the electrochromic compound can exhibit a good color value at the time of coloring and decoloring.

  Examples of the metal oxide electrochromic compound include tungsten oxide, molybdenum oxide, iridium oxide, indium oxide, titanium oxide, nickel oxide, vanadium oxide, and Prussian blue.

  The materials used for the electrochromic compound in each electrochromic layer in the electrochromic display element 20 are preferably unified so that they are all oxidation coloring materials or all reduction coloring materials. .

  The first insulating layer 24 is electrically insulated from the first display electrode 22 provided with the first electrochromic layer 23 and the second display electrode 25 provided with the second electrochromic layer 26. Isolate these as you can.

  The second insulating layer 27 is electrically insulated from the second display electrode 25 provided with the second electrochromic layer 26 and the third display electrode 28 provided with the third electrochromic layer 29. Isolate these as you can.

  Note that the first insulating layer 24 may not be provided as long as the interelectrode resistance between the first display electrode 22 and the second display electrode 25 can be increased. For example, the interelectrode resistance between the first display electrode 22 and the second display electrode 25 can be increased by increasing the film thickness of the first electrochromic layer 23. Similarly, if the interelectrode resistance between the second display electrode 25 and the third display electrode 28 can be increased, the second insulating layer 27 may not be provided.

  By providing these insulating layers, color development and decoloration in each electrochromic layer can be individually controlled, so that high-definition full-color display is possible.

The material of the insulating layer is not particularly limited as long as it is a porous insulator, but a material having high insulation and durability and excellent film formability is preferable. A material containing at least ZnS is preferable. This is because ZnS enables high-speed film formation by sputtering. This is because ZnS can reduce damage to the electrochromic layer during film formation. For example, it is preferable to use ZnS—SiO ₂ , ZnS—SiC, ZnS—Si, ZnS—Ge, or the like.

  The counter substrate 35 is a substrate for supporting a laminated structure of the drive element layer 34, the counter electrode 33, the charge holding layer 32, and the like.

  The material of the counter substrate 35 is preferably a light transmissive material. For example, glass, a plastic film, etc. are mentioned.

  The counter electrode 33 develops or decolors the first electrochromic layer 23, the second electrochromic layer 26, and the third electrochromic layer 29 based on the voltage generated between the display electrodes.

  The material of the counter electrode 33 is not particularly limited as long as it is a conductive material. For example, ITO, FTO, zinc oxide, or the like can be given as a light-transmitting conductive material. Moreover, zinc, platinum, etc. are mentioned as an electroconductive metal material. Carbon or the like may be used.

  The drive element layer 34 includes a plurality of drive elements and drives the drive elements according to the selected pixel. Note that the pixel density is proportional to the number of driving elements.

  The charge retention layer 32 relieves transfer of charges generated by a voltage applied between each display electrode and the counter electrode 33. By providing the charge retention layer 32, it is possible to improve the repeated durability of coloring and decoloring in each electrochromic layer. By increasing the durability repeatedly, high-definition display is possible in a display device using an electrochromic display element.

  As a material of the charge retention layer 32, a mixed material of a conductive fine particle material or a semiconductor fine particle material (fine particle material) and a polymer material can be used.

  Although there is no special restriction | limiting as a polymer material, For example, an acrylic type, an alkyd type, a fluorine type, an isocyanate type, a urethane type, an amino type, an epoxy type, a phenol type etc. are mentioned.

  Examples of the conductive fine particles include ITO, FTO, ATO and the like.

  Examples of the semiconductor fine particles include oxides such as titanium, zirconium, hafnium, chromium, molybdenum, tungsten, vanadium, niobium, tantalum, silver, zinc, strontium, iron, and nickel.

  In addition, when all the materials used for the electrochromic compound in each electrochromic layer are oxidation coloring materials, it is particularly preferable to use ATO as the fine particle material mixed with the polymer material. In addition, when all the materials used for the electrochromic compound in each electrochromic layer are reduction coloring materials, it is particularly preferable to use tungsten oxide as the fine particle material mixed with the polymer material. By using ATO in the case of an oxidative coloring material and using tungsten oxide in the case of a reducing chromogenic material, the driving voltage of the electrochromic display element can be lowered and the durability can be repeatedly improved.

  The wall member 36 surrounds each display electrode, each electrochromic layer, and the white reflective layer 31. As the material of the wall member 36, an ultraviolet curable resin material such as an acrylate type (radical polymerization type) or an epoxy type (cationic polymerization type), or a thermosetting resin material such as an epoxy type, a phenol type, or a melamine type can be used.

  The white reflective layer 31 is for improving the white reflectance in the electrochromic display element 20. The white reflective layer 31 includes titanium oxide particles and a metal hydroxide that covers the surfaces of the titanium oxide particles. Although the surface of the titanium oxide particles can be structured not to be coated with a metal hydroxide, in order to further increase the white reflectance of the electrochromic display element 20, particularly in the reflective display, the structure to be coated is used. Is more preferable.

  The particle size of the titanium oxide particles is preferably about 200 nm to 3 μm, and particularly preferably about 300 nm.

  The film thickness of the metal hydroxide covering the titanium oxide particles is preferably 0.2 nm or more and 4.0 nm or less.

  By coating the surface of the titanium oxide particles contained in the white reflective layer 31 with a metal hydroxide, the photocatalytic activity of titanium oxide can be suppressed. In addition, the surface of the titanium oxide particles contained in the white reflective layer 31 is coated with a metal hydroxide to suppress the photocatalytic activity of the titanium oxide contained in the white reflective layer 31, resulting in the light resistance of the electrochromic display element. It is suggested by the experimental result mentioned later that can be improved.

  The metal hydroxide material is not particularly limited as long as it can effectively suppress the suppression of the photocatalytic activity of the titanium oxide particles, and examples thereof include iron hydroxide and aluminum hydroxide. It is particularly preferable to use aluminum hydroxide.

  The electrolyte layer 30 fills a space generated between the counter substrate 35 and the display substrate 21 surrounded by the wall member 36. The electrolyte layer 30 fills the space so that each electrochromic layer is included in the electrolyte layer 30. The electrolyte layer 30 moves electric charge between the first display electrode 22, the second display electrode 25, or the third display electrode 28 and the counter electrode 33, and the first electrochromic layer 23, the second display electrode Coloring or erasing of the electrochromic layer 26 and the third electrochromic layer 29 is promoted.

  As the material of the electrolyte layer 30, inorganic ion salts such as alkali metal salts and alkaline earth metal salts, quaternary ammonium salts, acids, and supporting salts of alkalis can be used.

For example, LiClO ₄ , LiBF ₄ , LiAsF ₆ , LiPF ₆ , LiCF ₃ SO ₃ , LiCF ₃ COO, KCl, NaCl, NaBF ₄ , NaSCN, KBF ₄ , Mg (ClO ₄ ) ₂ , Mg (BF ₄ ) ₂ etc. Can be mentioned.

  Further, as the material of the electrolyte layer 30, an ionic liquid can be used. The organic ionic liquid is preferably used because it has a molecular structure showing the liquid in a wide temperature range including room temperature.

  Examples of the cationic component include imidazole derivatives such as N, N-dimethylimidazole salt, N, N-methylethylimidazole salt, and N, N-methylpropylimidazole salt. Further, pyridinium derivatives such as N, N-dimethylpyridinium salt and N, N-methylpropylpyridinium salt can be mentioned. In addition, aliphatic quaternary ammonium compounds such as trimethylpropylammonium salt, trimethylhexylammonium salt, and triethylhexylammonium salt can be used.

For example, it is preferable to use a compound containing fluorine as the anion component in consideration of stability in the air. For _{example, BF 4 -, CF 3 SO} 3 -, PF 4 -, (CF 3 SO 2) 2 N-, and the like.

  That is, as the material for the electrolyte layer 30, it is preferable to use an ionic liquid in which a cation component and an anion component are arbitrarily combined. The ionic liquid may be directly dissolved in any of photopolymerizable monomers, oligomers, and liquid crystal materials. If the solubility is poor, a small amount of solvent (for example, propylene carbonate, acetonitrile, γ-butyrolactone, ethylene carbonate, sulfolane, dioxolane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, -dimethoxyethane, -ethoxymethoxyethane, Polyethylene glycol, alcohols, etc.), and the solution may be mixed with any of photopolymerizable monomers, oligomers, and liquid crystal materials.

  Furthermore, a protective layer may be provided so as to be in contact with the surface of each of the first electrochromic layer 23 and the second electrochromic layer 26 on the side opposite to the display substrate 21. By providing the protective layer, the adhesion with the adjacent layers (for example, the first insulating layer 24, the second insulating layer 27, etc.) of each of the first electrochromic layer 23 and the second electrochromic layer 26, solvent The solubility of the electrochromic display element 20 can be improved.

  As a material for the protective layer, an organic polymer material is preferably used. For example, general resins such as polyvinyl alcohol, poly N vinylamide, polyester, polystyrene, and polypropylene can be used.

  An inorganic protective layer may be provided between the third electrochromic layer 29 and the electrolyte layer 30. By providing the inorganic protective layer, it is possible to improve the dissolution resistance, corrosion resistance, and the like of the third electrochromic layer 29 with respect to the electrolyte layer 30, and to improve the durability of the electrochromic display element 20.

  The electrochromic display element 20 shown in FIG. 1 has three electrochromic layers including a first electrochromic layer 23, a second electrochromic layer 26, and a third electrochromic layer 29. It is not limited. For the purpose of monochrome image display instead of full-color image display, for example, it may have only one electrochromic layer like the electrochromic display element 20A shown in FIG.

  According to the electrochromic display element 20 described above, the surface of titanium oxide nanoparticles used as electrochromic compound-supported particles is coated with a metal hydroxide, thereby suppressing the photocatalytic activity of titanium oxide and reflecting type. In both cases of display and transmissive display, the light resistance of the electrochromic display element can be improved. In addition, by coating the surface of titanium oxide particles used as a material for the white reflective layer with a metal hydroxide, it is possible to increase the white reflectance particularly in a reflective display.

(Multicolor display of electrochromic display elements)
Next, multicolor display of the electrochromic display element will be described.

  The electrochromic display element 20 shown in FIG. 1 can easily perform multicolor display by having the above-described structure.

  In the electrochromic display element 20, the first electrochromic layer 23 develops a cyan color, the second electrochromic layer 26 develops a magenta color, and the third electrochromic layer 29 develops a yellow color. .

  Since the first display electrode 22 and the second display electrode 25 are provided separately via the first insulating layer 24, the electrochromic display element 20 includes the counter electrode 33 and the first display electrode. The voltage generated between the counter electrode 33 and the second display electrode 25 can be controlled independently.

  In addition, since the second display electrode 25 and the third display electrode 28 are provided separately via the second insulating layer 27, the electrochromic display element 20 includes the counter electrode 33 and the second electrode. The voltage generated between the display electrode 25 and the voltage generated between the counter electrode 33 and the third display electrode 28 can be controlled independently.

  That is, the electrochromic display element 20 includes a first electrochromic layer 23 provided in contact with the first display electrode 22, a second electrochromic layer 26 provided in contact with the second display electrode 25, The third electrochromic layer 29 provided in contact with the third display electrode 28 can be independently developed or decolored.

  As a result, the electrochromic display element 20 can arbitrarily color or decolor each electrochromic layer based on the voltage applied to the counter electrode and each display electrode. For example, color development of only the first electrochromic layer 23, color development of only the second electrochromic layer 26, color development of only the first electrochromic layer 23 and the third electrochromic layer 29, etc. Can develop color. Further, a desired multicolor display can be performed by appropriately adjusting the color, color density, brightness, and the like of each electrochromic layer based on the voltage applied to the counter electrode and each display electrode.

  In the electrochromic display element 20, the color that the first electrochromic layer 23 develops is not limited to cyan. Further, the color that the second electrochromic layer 26 develops is not limited to magenta. Further, the color developed by the third electrochromic layer 29 is not limited to the yellow color.

  Since the electrochromic display element 20 uses titanium oxide as the electrochromic compound-carrying particles contained in each electrochromic layer, it can perform multicolor display with excellent response speed of color development or decoloration. In addition, since the electrochromic display element 20 covers the surface of the titanium oxide nanoparticles contained in each electrochromic layer with a metal hydroxide, it suppresses the photocatalytic activity of the titanium oxide and has excellent light resistance. Can be maintained. Thus, the electrochromic display element 20 can realize full color display (multicolor display) excellent in light resistance while maintaining high definition and high contrast.

(Method for manufacturing electrochromic display element)
Next, an example of a method for manufacturing the electrochromic display element 20 will be described with reference to FIG.

  As shown in step S11 to step S23 in FIG. 4, the method for manufacturing the electrochromic display element 20 includes a first display electrode formation step (step S11) in which the first display electrode 22 is formed on the display substrate 21. And a first electrochromic layer forming step (step S12) for forming the first electrochromic layer 23 thereon, and a first insulating layer forming step (step for forming the first insulating layer 24 thereon) S13), a second display electrode forming step for forming the second display electrode 25 thereon (step S14), and a second electrochromic layer forming step for forming the second electrochromic layer 26 thereon (Step S15), a second insulating layer forming step for forming the second insulating layer 27 thereon (Step S16), and a third display electrode forming step for forming the third display electrode 28 thereon (Step S17) and on it A third electrochromic layer forming step (step S18) for forming the third electrochromic layer 29, a white reflecting layer forming step (step S19) for forming the white reflecting layer 31 thereon, and driving on the counter substrate 35 A driving element layer forming step (step S20) for forming the element layer 34, a counter electrode forming step (step S21) for forming the counter electrode 33 thereon, and a charge holding layer formation for forming the charge holding layer 32 thereon A process (step S22) and a bonding process (step S23) for bonding the display substrate 21 and the counter substrate 35 to each other.

(First display electrode forming step)
First, the first display electrode formation step shown in step S11 of FIG. 4 is performed.

  An ITO film having a film thickness of about 100 nm and a surface resistance of about 200Ω / □ is formed on the display substrate 21 (for example, a glass substrate having a length of 40 mm and a width of 40 mm) by sputtering, and the first display electrode 22 is formed.

  The film forming method is not limited to the sputtering method, and other vacuum film forming methods such as an ion plating method can be applied.

(First electrochromic layer forming step)
Next, the first electrochromic layer forming step shown in step S12 of FIG. 4 is performed.

  First, a dispersion of titanium oxide nanoparticles coated with aluminum hydroxide is applied onto the first display electrode 22 by spin coating. Thereafter, annealing is performed at 120 ° C. for 15 minutes so that the first display electrode 22, the titanium oxide nanoparticles, and the titanium oxide nanoparticles are partially bonded to each other. Thus, a titanium oxide particle film including a large number of titanium oxide nanoparticles coated with aluminum hydroxide is formed.

  The weight ratio of titanium oxide to aluminum hydroxide is 88.3%: 11.7%. The particle size of the titanium oxide nanoparticles is 20 nm.

  Thereafter, 2,2,3,3-containing 1 wt% of electrochromic compound 4,4 ′-(isooxazole-3,5-diyl) bis (1- (2-phosphonoethyl) pyridinium) bromide on the titanium oxide particle film. A tetrafluoropropanol (hereinafter referred to as “TFP”) solution is applied by spin coating, and annealed at 120 ° C. for 10 minutes. Thus, the first electrochromic layer 23 made of the titanium oxide particle film and the electrochromic compound is formed.

  Thereafter, a protective layer is formed on the first electrochromic layer 23 by applying an ethanol solution containing 0.1 wt% poly N vinylamide and an aqueous solution containing 0.5 wt% polyvinyl alcohol by spin coating.

(First insulating layer forming step)
Next, a first insulating layer forming step shown in step S13 in FIG. 4 is performed.

A ZnS—SiO ₂ film having a thickness of about 140 nm is formed on the protective layer by sputtering, and the first insulating layer 24 is formed. The composition ratio of ZnS and SiO ₂ is 8: 2.

  As a film formation method, a vacuum film formation method such as an evaporation method, a sputtering method, or an ion plating method can be applied.

(Second display electrode forming step)
Next, a second display electrode forming step shown in step S14 of FIG. 4 is performed.

  On the first insulating layer 24, an ITO film having a film thickness of about 100 nm and a surface resistance of about 200Ω / □ is formed by sputtering to form a second display electrode 25.

(Second electrochromic layer forming step)
Next, the second electrochromic layer forming step shown in step S15 of FIG. 4 is performed.

  First, a dispersion of titanium oxide nanoparticles coated with aluminum hydroxide is applied onto the second display electrode 25 by spin coating. After that, an annealing process is performed at 120 ° C. for 15 minutes so that the second display electrode 25, the titanium oxide nanoparticles, and the titanium oxide nanoparticles are partially bonded to each other. Thus, a titanium oxide particle film including a large number of titanium oxide nanoparticles coated with aluminum hydroxide is formed.

  The weight ratio of titanium oxide to aluminum hydroxide is 88.3%: 11.7%. The particle size of the titanium oxide nanoparticles is 20 nm.

  Thereafter, 1 wt% of electrochromic compound 4,4 ′-(1-phenyl-1H-pyrrole-2,5-diyl) bis (1- (4-phosphonomethyl) benzyl) pyridinium) bromide is contained on the titanium oxide particle film. TFP solution is applied by spin coating and annealed at 120 ° C for 10 minutes. Thus, the second electrochromic layer 26 made of the titanium oxide particle film and the electrochromic compound is formed.

  Thereafter, a protective layer is formed on the second electrochromic layer 26 by applying an ethanol solution containing 0.1 wt% poly N vinylamide and an aqueous solution containing 0.5 wt% polyvinyl alcohol by a spin coating method.

(Second insulating layer forming step)
Next, a second insulating layer forming step shown in step S16 in FIG. 4 is performed.

A ZnS—SiO ₂ film having a thickness of about 140 nm is formed on the protective layer by sputtering, and the second insulating layer 27 is formed. The composition ratio of ZnS and SiO ₂ is 8: 2.

  As a film formation method, a vacuum film formation method such as an evaporation method, a sputtering method, or an ion plating method can be applied.

(Third display electrode forming step)
Next, a third display electrode forming step shown in step S17 in FIG. 4 is performed.

  On the second insulating layer 27, an ITO film having a film thickness of about 100 nm and a surface resistance of about 200Ω / □ is formed by sputtering, and a third display electrode 28 is formed.

(Third electrochromic layer forming step)
Next, a third electrochromic layer forming step shown in step S18 of FIG. 4 is performed.

  First, a dispersion of titanium oxide nanoparticles coated with aluminum hydroxide is applied onto the third display electrode 28 by spin coating. After that, an annealing process is performed at 120 ° C. for 15 minutes so that the third display electrode 28, the titanium oxide nanoparticles, and the titanium oxide nanoparticles are partially bonded to each other. Thus, a titanium oxide particle film including a large number of titanium oxide nanoparticles coated with aluminum hydroxide is formed.

  The weight ratio of titanium oxide to aluminum hydroxide is 88.3%: 11.7%. The particle size of the titanium oxide nanoparticles is 20 nm.

  Thereafter, on the titanium oxide particle film, the electrochromic compound 4,4 ′-(4,4 ′-(1,3,4-oxadiazole-2,5-diyl) bis (4,1-phenylene)) bis (1 A TFP solution containing 1 wt% of (8-phosphonooctyl) pyridinium) bromide is applied by spin coating, and annealed at 120 ° C. for 10 minutes. Thus, a third electrochromic layer 29 made of the titanium oxide particle film and the electrochromic compound is formed.

(White reflective layer forming process)
Next, the white reflective layer forming step shown in step S19 of FIG. 4 is performed.

  First, titanium oxide particles coated with aluminum hydroxide and a TFP dispersion of an aqueous polyurethane resin are applied onto the third electrochromic layer 29 by spin coating. Thereafter, annealing is performed at 120 ° C. for 10 minutes. Thus, the white reflective layer 31 including a large number of titanium oxide particles coated with aluminum hydroxide is formed.

  The weight ratio of titanium oxide to aluminum hydroxide is 91.1%: 8.9%. The particle size of the titanium oxide particles is 300 nm.

  Thereafter, the first display electrode 22, the second display electrode 25, the third display electrode 28, the first electrochromic layer 23, the second electrochromic layer 26, the third electrochromic layer 29, and the white reflective layer 31 is surrounded by a wall member 36 (see FIG. 1).

(Driving element layer forming step)
Next, the driving element layer forming step shown in step S20 of FIG. 4 is performed.

  A driving element layer 34 having a plurality of driving elements is formed by a known process on a counter substrate 35 (for example, a glass substrate having a length of 40 mm and a width of 40 mm) so that the pixel density is 140 ppi (Pixels per inch). .

(Counter electrode formation process)
Next, the counter electrode forming step shown in step S21 of FIG. 4 is performed.

  An ITO film having a thickness of about 100 nm is formed on the counter substrate 35 by sputtering. Thereafter, a plurality of counter electrodes 35 are formed by photolithography so as to correspond to the plurality of driving elements included in the driving element layer 34.

(Charge retention layer forming step)
Next, the charge retention layer forming step shown in step S22 of FIG. 4 is performed.

  The charge retention layer 32 is formed by mixing a polymer material and a fine particle material and dispersing them in a dispersion medium, and applying the mixed material onto the drive element layer 34 and the counter electrode 33 by a spin coating method.

  Specifically, a TFP dispersion of an aqueous polyurethane resin and ATO nanoparticles is applied on the driving element layer 34 and the counter electrode 35 by a spin coating method. Thereafter, the charge retention layer 32 having a film thickness of about 640 nm and a surface resistance of about 1.0E + 06Ω / □ is formed by performing an annealing process at 120 ° C. for 15 minutes.

  The weight ratio of the aqueous polyurethane resin to ATO is 55%: 45%.

  As a coating method, other printing methods such as a spin coating method and a blade coating method can be applied.

  The aqueous polyurethane resin and the TFP solution of ATO nanoparticles do not need to be selectively applied only on the counter electrode 33, and the counter electrode 33 formed corresponding to a plurality of drive elements included in the drive element layer 34. And the counter electrode 33 may be applied. Since it is not necessary to selectively apply the solution, the manufacturing process is simplified and the manufacturing cost is reduced when the charge holding layer 32 is formed compared to the case where the charge holding layer 32 is not formed. Can do.

(Lamination process)
Next, the bonding process shown in step S23 of FIG. 4 is performed.

  The counter substrate 35 having the layers up to the charge holding layer 32 and the display substrate 21 having the layers up to the white reflective layer 31 are bonded with the electrolyte sandwiched so that the counter electrode and the display electrode face each other.

Specifically, in the display substrate 21 surrounded by the wall member 36, an electrolyte precursor material is injected from above the white reflective layer 31. The display substrate 21 and the counter substrate 35 are bonded together by sealing the injection port. Thereafter, ultraviolet light is irradiated for 2 minutes from the counter electrode 33 side by a high-pressure mercury lamp. Since the precursor material can be photopolymerized and separated by irradiation with ultraviolet light, the electrolyte layer 30 can be formed between the two substrates. The ultraviolet light has a center wavelength of 365 nm and an intensity of 50 mW / cm ² .

  The precursor material of the electrolyte layer 30 is adjusted before the electrochromic display element 20 is manufactured. In the bonding step in step S23, the precursor material of the electrolyte layer 30 adjusted in advance is used. As an example of a method of adjusting the precursor material of the electrolyte layer 30, first, a propylene carbonate solution of tetrabutylammonium perchlorate (TBAP) and a molar concentration of TBAP of about 2.0 mol are used. Adjust to / l. Thereafter, a mixture of a liquid crystal composition for PNLC (Polymer Network Liquid Crystal), a monomer composition, and a polymerization initiator is mixed into the solution. Thereafter, the molar concentration of TBAP in the propylene carbonate solution is adjusted again to be about 0.04 mol / l. Thereafter, in order to regulate the film thickness of the electrolyte layer 30 to be manufactured, true spherical resin beads having a particle diameter of 10 μm are dispersed in the propylene carbonate solution at a concentration of 0.2 wt%. Thus, a precursor material for the electrolyte layer 30 can be obtained.

(Embodiment 2)
(Evaluation of light resistance of electrochromic display elements)
In this embodiment, the light resistance of an electrochromic display element will be described.

  The light resistance of the electrochromic display element was evaluated from the color difference retention rate of the electrochromic display element.

From the change in color difference retention rate, the effect produced by coating the surface of the titanium oxide particles contained in the white reflective layer or the surface of the titanium oxide nanoparticles contained in the electrochromic layer with a metal hydroxide was investigated. Further, from the change in color difference retention rate, the effect produced by using the metal hydroxide as aluminum hydroxide or iron hydroxide (Fe (OH) ₃ ) was examined.

  The evaluation results are shown in FIG.

  As the electrochromic display element, five different types of electrochromic display elements were used. The structures of the five types of electrochromic display elements are different from each other in the following structure (see (1) to (5)). The other structures except for the different structures are all the same as the structure of the electrochromic display element 20 shown in the first embodiment. Structures (1) to (4) were used as electrochromic display elements of Examples (Examples 1 to 4). Structure (5) was used as a comparative electrochromic display element (Comparative Example 1).

As the first type, (1) an electrochromic display element in which the surface of titanium oxide particles contained in the white reflective layer and the electrochromic layer was coated with aluminum hydroxide was used. As the second type, (2) an electrochromic display element in which only the surface of titanium oxide particles contained in the electrochromic layer was coated with aluminum hydroxide was used. As the third type, (3) an electrochromic display element in which only the surface of the titanium oxide particles contained in the white reflective layer was coated with aluminum hydroxide was used. As a fourth type, (4) an electrochromic display element in which the surface of titanium oxide particles contained in the white reflective layer and the electrochromic layer was coated with iron hydroxide (Fe (OH) ₃ ) was used. As the fifth type, (5) an electrochromic display element in which neither the surface of titanium oxide particles contained in the white reflective layer nor the electrochromic layer was coated with a metal hydroxide was used.

  The color difference retention was calculated based on the color difference ΔE_α before irradiating the electrochromic display element with light and the color difference ΔE_β after irradiating the electrochromic display element with light. Light irradiation was performed by irradiating the electrochromic display element to be measured with light from a white fluorescent lamp containing a UV component at an illuminance of 15000 Lx for 100 hours.

  The color difference ΔE was calculated as follows. First, using a spectrocolorimeter, the difference in color density between two states, a state in which the electrochromic display element to be measured is completely decolored and a state in which the electrochromic layer is colored in the electrochromic display element to be measured Measured color. The color difference ΔE was calculated in correspondence with the binary coordinates expressed in the CIE Lab color system (L * a * b * color system), and used as an index of color density. The color difference retention rate was calculated by dividing the color difference ΔE_β by the color difference ΔE_α with the color difference ΔE_β after the light irradiation as the color difference ΔE_α before the light irradiation.

  The CIE Lab color system is a color expression expressed in coordinates on a uniform color space consisting of lightness L * and chrominance index a *, b *, and is based on the color vision of the human eye. Is defined.

  First, the color difference retention ratio before and after light irradiation in the electrochromic display element of (1) was calculated.

  The particle size of the titanium oxide particles contained in the white reflective layer was 300 nm, and the weight ratio of the titanium oxide particles to aluminum hydroxide was 91.1%: 8.9%. The particle size of the titanium oxide nanoparticles contained in the electrochromic layer was 20 nm, and the weight ratio of the titanium oxide nanoparticles to aluminum hydroxide was 88.3%: 11.7%.

  The color difference ΔE_α before the light irradiation was 54.8.

  The color difference ΔE_β after light irradiation was 49.0.

  That is, when the surface of the titanium oxide particles contained in the white reflective layer and the electrochromic layer was coated with aluminum hydroxide, the color difference retention rate after light irradiation was 89.4%. This result suggests that the electrochromic display element (1) has excellent light resistance.

  Next, in the electrochromic display element of (2), the color difference retention ratio before and after light irradiation was calculated.

  The particle size of the titanium oxide nanoparticles contained in the electrochromic layer was 20 nm, and the weight ratio of the titanium oxide nanoparticles to aluminum hydroxide was 88.3%: 11.7%.

  The color difference ΔE_α before the light irradiation was 55.1.

  The color difference ΔE_β after light irradiation was 37.0.

  That is, when only the surface of the titanium oxide nanoparticles contained in the electrochromic layer was coated with aluminum hydroxide, the color difference retention rate after light irradiation was 67.1%. This result suggests that the electrochromic display element of (2) has lower light resistance than the electrochromic display element of (1).

  Next, the color difference retention ratio before and after light irradiation in the electrochromic display element of (3) was calculated.

  The particle size of the titanium oxide particles contained in the white reflective layer was 300 nm, and the weight ratio of the titanium oxide particles to aluminum hydroxide was 91.1%: 8.9%.

  The color difference ΔE_α before light irradiation was 53.4.

  The color difference ΔE_β after light irradiation was 24.2.

  That is, when only the surface of the titanium oxide particles contained in the white reflective layer was coated with aluminum hydroxide, the color difference retention rate after light irradiation was 45.3%. From this result, it is suggested that the light resistance is improved when the electrochromic layer is coated with aluminum hydroxide as compared with the case where the white reflective layer is coated with aluminum hydroxide.

  Next, the color difference retention ratio before and after light irradiation in the electrochromic display element of (4) was calculated.

The particle size of the titanium oxide particles contained in the white reflective layer was 300 nm, and the weight ratio of the titanium oxide particles to iron hydroxide (Fe (OH) ₃ ) was 90.3%: 9.7%. The particle size of the titanium oxide nanoparticles contained in the electrochromic layer was 20 nm, and the weight ratio of the titanium oxide nanoparticles to iron hydroxide (Fe (OH) ₃ ) was 87.5%: 12.5%.

  The color difference ΔE_α before the light irradiation was 55.7.

  The color difference ΔE_β after light irradiation was 42.9.

That is, when the surface of the titanium oxide particles contained in the white reflective layer and the electrochromic layer was coated with iron hydroxide (Fe (OH) ₃ ), the color difference retention rate after light irradiation was 77.1%. From this result, although it is inferior to the case where the white reflective layer and the electrochromic layer are coated with aluminum hydroxide, the case where the white reflective layer and the electrochromic layer are coated with iron hydroxide (Fe (OH) ₃ ) is also electrochromic. It is suggested that the display element has excellent light resistance. In addition, it is suggested that aluminum hydroxide has a greater effect of suppressing photocatalytic activity on titanium oxide than iron hydroxide (Fe (OH) ₃ ).

  Next, the color difference retention ratio before and after light irradiation in the electrochromic display element of (5) was calculated.

  The color difference ΔE_α before light irradiation was 55.4.

  The color difference ΔE_β after light irradiation was 11.0.

  That is, when neither of the surfaces of the titanium oxide particles contained in the white reflective layer and the electrochromic layer was coated with a metal hydroxide, the color difference retention rate after light irradiation was 19.8%. This result suggests that the light resistance of the electrochromic display element is very poor.

  Comparing the above five results, when the surface of the titanium oxide particles contained in the white reflective layer and the electrochromic layer are both coated with a metal hydroxide, and the metal hydroxide is aluminum hydroxide, It was confirmed that the color difference_β after light irradiation was the largest and the color difference retention rate was high.

  Therefore, it is suggested that an electrochromic display element having excellent light resistance can be realized by coating the surface of titanium oxide nanoparticles contained in the electrochromic layer with a metal hydroxide.

  Further, it is suggested that an electrochromic display element having further excellent light resistance can be realized by coating the surface of titanium oxide particles contained in the white reflective layer with a metal hydroxide.

  When only one electrochromic layer is formed and the color difference retention ratio before and after light irradiation in a monochrome display electrochromic display element is calculated, the color difference ΔE_α before light irradiation is 53.0, and the color difference ΔE_β after light irradiation is 47.9. The color difference retention rate after light irradiation was 90.3%. In the colorimetry using the spectrocolorimeter, the electrochromic display element was superimposed on a white plate for colorimetry. This suggests that an electrochromic display element having excellent light resistance can be realized even in the case of monochrome display.

(Embodiment 3)
(Information equipment using electrochromic display elements)
In the present embodiment, a case where the electrochromic display element 20 according to the first embodiment is applied to an electronic book reader will be described. The electrochromic display element 20 is not limited to an electronic book reader, and can be applied to any information device including a display device such as an electronic advertisement, a mobile personal computer, and a portable terminal.

  FIG. 6 shows an example of a schematic structure of the electronic book reader 100.

  The electronic book reader 100 includes a display device 101, a main controller 102, a ROM 103, a RAM 104, a flash memory 105, a character generator 106, and an interface 107. The display device 101 includes a display panel 111 with a touch panel, a touch panel driver 112, a display controller 113, and a VRAM 114.

  In the structure shown in FIG. 6, the character generator 106 is provided outside the display device 101. However, the character generator 106 may be provided inside the display device 101. Further, the display panel 111 may not include a touch panel. If there is other input means, the display panel 111 may be provided with other input means. When the display panel 111 does not include a touch panel, the touch panel driver 112 is not necessary.

  Note that the arrows shown in FIG. 6 represent the flow of typical signals and information, and do not represent the entire connection relationship of each block.

  The display panel 111 with a touch panel includes a drive circuit for individually driving the electrochromic display element 20 according to the first embodiment, the first electrochromic layer 23, the second electrochromic layer 26, and the third electrochromic layer 29. Including. The drive circuit includes a drive element layer 34, and the drive element layer 34 has a plurality of drive elements corresponding to the respective counter electrodes 33. The display panel 111 drives a driving element corresponding to the selected pixel based on the pixel selection signal output from the display controller 113, and applies a predetermined voltage to the selected pixel. The pixel selection signal is a signal that designates the vertical position and the horizontal position of the selected pixel. Further, based on the color designation signal output from the display controller 113, the display panel 111 applies a predetermined voltage to the corresponding display electrode according to the designated color. Based on signals such as a pixel selection signal and a color designation signal, the display panel 111 displays a moving image, a still image, or the like.

  Further, the display panel 111 outputs a signal based on the touch position to the touch panel driver 112 when the user touches the touch panel.

  Since the display panel 111 includes the electrochromic display element 20 according to the first embodiment, high-definition full-color display (multicolor display) can be realized while maintaining high white reflectance and a high contrast ratio. Can do. Actually, even after displaying and erasing a full-color image alternately 1000 times, no special change was observed in the display state of the image.

  Further, the display panel 111 can switch between color development and color erasure at high speed. Actually, the time required from the start of driving to image acquisition and the time required to erase the acquired image were about 500 mm seconds.

  In addition, since the display panel 111 has excellent light resistance, the display panel 111 has high fastness to light such as sunlight and room light, and can maintain high-visibility image display even when light is irradiated for a long time. In fact, even after standing for about 30 minutes after displaying a full-color image, there was no change in the appearance of the image, and blurring of the image could not be recognized.

  The VRAM 114 stores display data for displaying a moving image or a still image on the display panel 111. The display data individually corresponds to a plurality of pixels included in the display panel 111. Therefore, the display data includes display color information corresponding to each pixel.

  The display controller 113 reads display data stored in the VRAM 114 at predetermined timings, and individually controls display colors of a plurality of pixels included in the display panel 111 according to the display data. The display controller 113 outputs to the display panel 111 a pixel selection signal for specifying a pixel to be colored and a color designation signal for specifying a color.

  The touch panel driver 112 outputs position information corresponding to the position touched by the user on the display panel 111 to the main controller 102.

  The main controller 102 comprehensively controls each unit such as the RAM 104, the flash memory 105, the character generator 106, the interface 107, and the VRAM 114 in accordance with a program stored in the ROM 103.

  For example, when the power is turned on by the user, the main controller 102 reads the initial menu screen data from the ROM 103, refers to the character generator 106, converts the initial menu screen data into dot data, and converts the dot data into , Transfer to VRAM114. Thus, the initial menu screen is displayed on the display panel 111. At this time, a list of contents stored in the flash memory 105 is displayed on the display panel 111. When one of the menus on the display panel 111 is selected by the user and the display portion is touched, the main controller 102 acquires the selection content of the user based on the position information from the touch panel driver 112.

  When the user designates the content and requests to view the content, the main controller 102 reads the electronic data of the content from the flash memory 105 and refers to the character generator 106 to convert the electronic data into dot data. Then, the dot data is transferred to the VRAM 114.

  When the user requests to purchase content via the Internet, the main controller 102 connects to a predetermined purchase site via the interface 107 and functions as a normal browser. When information from the purchase site is displayed on the display panel 111 and the user purchases the content, electronic data of the content is downloaded. The main controller 102 stores the electronic data of the content in the flash memory 105.

  The ROM 103 stores various programs described in codes readable by the main controller 102 and various data necessary for executing the programs.

  The RAM 104 is a working memory.

  The flash memory 105 stores electronic data of books that are contents.

  The character generator 106 stores dot data corresponding to various character data.

  The interface 107 controls connection with an external device. The interface 107 can connect a memory card, a personal computer, and a public line. The connection to the personal computer and the public line can be either wired or wireless.

  According to the electronic book reader 100 according to the present embodiment, since the electrochromic element shown in the first embodiment is applied to the touch panel, light resistance is obtained in both cases of the reflective display and the transmissive display. Can be increased.

(Embodiment 4)
(Structure of electrochromic light control lens)
FIG. 7 is a cross-sectional view illustrating an electrochromic light control lens according to this embodiment. Referring to FIG. 7, the electrochromic light control lens 110 includes a lens 120 and a thin film light control function unit 130 provided in contact with the lens 120. The electrochromic light control lens 110 may include a hard coat layer for preventing scratches, an antireflection layer for suppressing reflection, and the like as necessary.

  As a manufacturing method of the electrochromic light control lens 110, the manufacturing method of the electrochromic display element 20 in Embodiment 1 can be referred to, and thus detailed description thereof is omitted. As an example of the manufacturing method, the first electrode layer 131, the electrochromic layer 132, the insulating porous layer 133, the second electrode layer 134, and the deterioration preventing layer 135 are sequentially stacked on the lens 120, The method includes a step of filling the insulating porous layer 133 with an electrolyte from the through-hole formed in the electrode layer 134 and the deterioration preventing layer 135, a step of forming the protective layer 136 by a coating method after the electrolyte is injected, and the like. It is done. By forming the protective layer 136 by a coating method after electrolyte injection, the electrochromic light control lens 110 can be thinned. For this reason, compared with the structure which bonds two lenses together, it is easy to aim at weight reduction and cost reduction.

  In the electrochromic light control lens 110, the electrochromic layer 132, the second electrode layer 134, and the deterioration preventing layer 135 are porous layers. A number of through holes formed in these layers are used as injection holes for filling the insulating porous layer 133 with an electrolyte. Since these layers have a large number of through holes, the second electrode layer 134 having low resistance can be formed before the electrolyte is filled. For this reason, the performance of the electrochromic light control lens 110 can be improved.

  Note that the deterioration preventing layer 135 and the electrochromic layer 132 can also be referred to as electroactive layers. In this case, the electrochromic light control lens 110 includes a lens, a first electrode layer provided in contact with the lens, a first electroactive layer provided in contact with the first electrode layer, An insulating porous layer provided in contact with the electroactive layer, a second electroactive layer provided in contact with the insulating porous layer, and a second electrode provided in contact with the second electroactive layer An electrode layer, and an electrolyte layer that fills a space between the first electrode layer and the second electrode layer and is in contact with the electroactive layer via the insulating porous layer. The surface of the titanium oxide particles contained in the electroactive layer can be structured to be coated with a metal hydroxide.

  The lens 120 is not particularly limited as long as it functions as a lens for spectacles, and includes a lens (just a glass plate or the like) whose power (refractive index) is not adjusted.

  As the material of the lens 120, it is preferable to use a material that is highly transparent, thin, and lightweight. Further, it is preferable that the expansion due to the thermal history is as small as possible, and a material having a high glass transition point Tg and a material having a small linear expansion coefficient are preferable.

  Specifically, in addition to glass, materials described in the technical summary document on high refractive index eyeglass lenses of the JPO can be used, for example, episulfide resin, thiourethane resin, methacrylate resin, Examples thereof include polycarbonate resins, urethane resins, and mixtures thereof. Moreover, you may form the primer for improving a hard coat and adhesiveness as needed.

  The planar shape of the lens 120 is not particularly limited, but may be a round planar shape, for example.

  The thin film dimming function unit 130 has a laminated structure in which the electrochromic layer 132 is colored and dimmed (dimmed) and a plurality of thin films are laminated. Specifically, the thin film dimming function unit 130 includes a first electrode layer 131, an electrochromic layer 132, an insulating porous layer 133, a second electrode layer 134, a deterioration preventing layer 135, and a protective layer 136 in order. It has a laminated structure (see FIG. 7). By providing the deterioration preventing layer 135 between the second electrode layer 134 and the protective layer 136, it is possible to realize an electrochromic light control lens capable of stable operation even after repeated use.

  The structure of the thin film light control function unit 130 is not limited to the structure shown in FIG. For example, the deterioration preventing layer 135 is provided between the second electrode layer and the protective layer 136 and between the second electrode layer and the insulating porous layer 133, and is provided on both surfaces of the second electrode layer 134. It may be provided in contact. For example, the deterioration preventing layer 135 may be provided only between the second electrode layer and the insulating porous layer 133.

  The electrochromic layer 132 (electroactive layer) and the deterioration preventing layer 135 (electroactive layer) have a relationship that when one layer undergoes an oxidation (reduction) reaction, the other layer undergoes a reduction (oxidation) reaction. Therefore, the electrochromic layer 132 and the deterioration preventing layer 135 may be provided at opposite positions. That is, for example, an electrochromic layer is provided between the second electrode layer and the protective layer 136 and between the second electrode layer and the insulating porous layer 133, and the deterioration preventing layer is provided in the first layer. It may be provided between the electrode layer 131 and the insulating porous layer 133. For example, the electrochromic layer may be provided only between the second electrode layer and the protective layer 136. For example, the electrochromic layer may be provided only between the second electrode layer and the insulating porous layer 133.

  The thickness of the thin-film light control function unit 130 is preferably about 2 μm to 200 μm. If the thickness of the thin-film light control function unit 130 is thicker than 200 μm, problems such as cracking and peeling occur during processing of the round lens, and adversely affecting the optical characteristics of the lens. The function cannot be obtained.

  The material of the first electrode layer 131 and the second electrode layer 134 is not particularly limited as long as it is a conductive material, but when used as a light control glass, it is necessary to ensure light transmission. For this reason, it is preferable to use a material having high light transmittance and excellent conductivity (hereinafter referred to as a transparent conductive material). By using the transparent conductive material, the transparency of the glass can be enhanced, and the contrast during coloring of the electrochromic layer 132 can be further enhanced.

  Examples of the transparent conductive material include indium oxide doped with tin (hereinafter referred to as ITO), tin oxide doped with fluorine (hereinafter referred to as FTO), tin oxide doped with antimony (hereinafter referred to as ATO), and the like. Inorganic materials can be used. In particular, any of indium oxide (hereinafter referred to as In oxide), tin oxide (hereinafter referred to as Sn oxide) or zinc oxide (hereinafter referred to as Zn oxide) formed by vacuum film formation. It is preferable to use an inorganic material including one.

In oxides, Sn oxides, and Zn oxides are preferable because they are materials that can be easily formed by a sputtering method and that can obtain good transparency and electrical conductivity. It is more preferable to use InSnO, GaZnO, SnO, In ₂ O ₃ , ZnO, or the like. Furthermore, silver, gold, carbon nanotubes, metal oxides and the like having high light transmittance are also useful. A network electrode made of carbon nanotubes, other highly conductive non-permeable materials, etc., formed in a fine network to increase light transmission is an electrode with high light transmission and excellent conductivity. Is particularly preferred.

  The thickness of each of the first electrode layer 131 and the second electrode layer 134 is preferably adjusted as appropriate so that an electric resistance value necessary for the oxidation-reduction reaction of the electrochromic layer 132 can be obtained. When ITO is used as the material of the first electrode layer 131 and the second electrode layer 134, the thickness of each of the first electrode layer 131 and the second electrode layer 134 is, for example, about 50 to 500 nm. Can do.

  As a manufacturing method of each of the first electrode layer 131 and the second electrode layer 134, a vacuum evaporation method, a sputtering method, an ion plating method, or the like can be used. In addition, as long as each material of the first electrode layer 131 and the second electrode layer 134 can be applied and formed, a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, a bar coating method, a roll coating method. Method, wire bar coating method, dip coating method, slit coating method, capillary coating method, spray coating method, nozzle coating method, gravure printing method, screen printing method, flexographic printing method, offset printing method, reverse printing method, inkjet printing method Various printing methods such as these can be used.

  The second electrode layer 134 is a porous electrode layer in which a large number of through holes penetrating in the thickness direction are formed. Examples of a method for forming fine through holes in the second electrode layer 134 include the following methods.

  The fine through-hole is formed by a method in which a layer having irregularities is formed in advance as a base layer before forming the second electrode layer 134, and the second electrode layer 134 is formed on the base layer. May be.

  In addition, the fine through-holes are formed in advance by forming a convex structure such as a micro pillar in the lower layer before forming the second electrode layer 134, and forming the convex structure after forming the second electrode layer 134. You may form by the method of removing.

  In addition, before forming the second electrode layer 134, the fine through-holes are preliminarily sprayed with a foamable polymer or the like on the lower layer, and heated or degassed after the second electrode layer 134 is formed. You may form by the method of giving a process etc. and making it foam.

  In addition, the fine through hole may be formed by a method of directly radiating various kinds of radiation to the second electrode layer 134 or using a processing apparatus using a laser beam.

  The fine through hole may be formed by a colloidal lithography method. Before the second electrode layer 134 is formed, fine particles are spread on the lower layer in advance, and a conductive film is formed on the surface on which the fine particles are spread by a vacuum film formation method or the like using the fine particles as a mask. The second electrode layer 134 having fine through holes can be formed by patterning by removing part of the conductive film together with the fine particles.

  The fine through hole may be formed by a known lift-off method using a photoresist, a dry film, or the like. After forming a desired photoresist pattern, a conductive film is formed, and the conductive film (unnecessary portion) formed on the photoresist pattern together with the photoresist pattern is removed, whereby the second electrode layer having fine through holes 134 can be formed. When a fine through hole is formed in the second electrode layer 134 by a known lift-off method, the photoresist used is used so that the light irradiation area to the object may be small in order to avoid damage to the lower layer due to light irradiation. It is preferable to use a negative type.

  Negative photoresists include, for example, polyvinyl cinnamate, styrylpyridinium formalized polyvinyl alcohol, glycol methacrylate / polyvinyl alcohol / initiator, polyglycidyl methacrylate, halomethylated polystyrene, diazoresin, bisazide / diene rubber, polyhydroxystyrene / Mention may be made of melamine / photoacid generators, methylated melamine resins, methylated urea resins and the like.

  The diameter of the fine through hole is preferably 10 nm or more and 100 μm or less. When the diameter of the through hole is smaller than 10 nm (0.01 μm), there arises a problem that the permeation of electrolyte ions is deteriorated. In addition, when the diameter of the fine through hole is larger than 100 μm, it is at a level that can be visually observed (the size of one pixel electrode in a normal display), which causes a problem in display performance immediately above the fine through hole.

  The ratio of the hole area to the surface area of the second electrode layer 134 (hole density) of the fine through-holes can be set as appropriate, and can be, for example, about 0.01 to 40%. If the hole density is too high, the surface resistance of the second electrode layer 134 is increased, so that the area of the region where the second electrode layer 134 is not formed is increased, thereby causing defects in the electrochromic layer. Further, if the hole density is too low, the permeability of the electrolyte ions is deteriorated, which causes a problem during driving.

  The electrochromic layer 132 is colored by a charge transfer (oxidation-reduction reaction) generated when a voltage is applied between the first electrode layer 131 and the second electrode layer 134. The electrochromic layer 132 is a porous layer in which a large number of through holes penetrating in the thickness direction are formed, and is filled with an electrolyte (not shown). The surface of the titanium oxide particles contained in the electrochromic layer 132 is covered with a metal hydroxide.

  The electrochromic layer 132 is a layer containing an electrochromic material, and any of an inorganic electrochromic compound and an organic electrochromic compound may be used as the electrochromic material. Moreover, you may use the conductive polymer known by showing electrochromism.

  Examples of the inorganic electrochromic compound include tungsten oxide, molybdenum oxide, iridium oxide, and titanium oxide. Examples of the organic electrochromic compound include viologen, rare earth phthalocyanine, styryl and the like.

  As the electrochromic layer 132, a structure in which an organic electrochromic compound is supported on conductive or semiconductive fine particles may be used. Specifically, it is a structure in which fine particles having a particle size of about 5 nm to 50 nm are sintered on the electrode surface, and an organic electrochromic compound having a polar group such as phosphonic acid, carboxyl group, silanol group or the like is adsorbed on the fine particle surface. .

  In such a structure, electrons are efficiently injected into the organic electrochromic compound by utilizing the large surface effect of the fine particles, so that a high-speed response is possible as compared with a conventional electrochromic display element. Furthermore, since a transparent film can be formed as a display layer by using fine particles, a high color density of the electrochromic dye can be obtained. A plurality of types of organic electrochromic compounds can also be supported on conductive or semiconductive fine particles.

  Specifically, azobenzene, anthraquinone, diarylethene, dihydroprene, dipyridine, styryl, styryl spiropyran, spirooxazine, spirothiopyran, thioindigo, tetrathiafulvalene, as electrochromic compounds of dye type , Terephthalic acid, triphenylmethane, triphenylamine, naphthopyran, viologen, pyrazoline, phenazine, phenylenediamine, phenoxazine, phenothiazine, phthalocyanine, fluoran, fulgide, benzopyran, Low molecular organic electrochromic compounds such as metallocenes, and conductive polymer compounds such as polyaniline and polythiophene can be used.

  Among these, it is particularly preferable to include a viologen-based compound or a dipyridine-based compound having a low color development / discoloration potential and a good color value. For example, it is preferable to include a dipyridine compound represented by the formula [Chemical Formula 1] (general formula).

なお、式［化１］（一般式）中、Ｒ１及びＲ２は、それぞれ独立に置換基を有してもよい炭素数１から８のアルキル基、又はアリール基を表し、Ｒ１又はＲ２の少なくとも一方は、ＣＯＯＨ、ＰＯ（ＯＨ）_２、Ｓｉ（ＯＣ_ｋＨ_２ｋ＋１）_３から選ばれる置換基を有する。Ｘは１価のアニオンを表す。ｎ、ｍ、ｌは０、１、又は２を表す。Ａ、Ｂ、Ｃは各々独立に置換基を有してもよい炭素数１から２０のアルキル基、アリール基、複素環基を表す。

In the formula [Chemical Formula 1] (general formula), R1 and R2 each independently represents an alkyl group having 1 to 8 carbon atoms or an aryl group which may have a substituent, and at least one of R1 and R2 _Has a substituent selected from COOH, PO (OH) ₂ , Si (OC _k H _{2k + 1} ) ₃ . X represents a monovalent anion. n, m, and l represent 0, 1, or 2. A, B and C each independently represent an alkyl group having 1 to 20 carbon atoms, an aryl group or a heterocyclic group which may have a substituent.

  On the other hand, as the metal complex-based or metal oxide-based electrochromic compound, inorganic electrochromic compounds such as titanium oxide, vanadium oxide, tungsten oxide, indium oxide, iridium oxide, nickel oxide, and Prussian blue can be used.

  Although it does not specifically limit as electroconductive or semiconductive fine particle, It is preferable to use a metal oxide. Specific materials include titanium oxide, zinc oxide, tin oxide, zirconium oxide, cerium oxide, yttrium oxide, boron oxide, magnesium oxide, strontium titanate, potassium titanate, barium titanate, calcium titanate, calcium oxide, Metal oxides mainly composed of ferrite, hafnium oxide, tungsten oxide, iron oxide, copper oxide, nickel oxide, cobalt oxide, barium oxide, strontium oxide, vanadium oxide, aluminosilicate, calcium phosphate, aluminosilicate, etc. can be used. .

  Moreover, these metal oxides may be used independently and 2 or more types may be mixed and used for them. In view of physical properties such as electrical properties such as electrical conductivity and optical properties, a kind selected from titanium oxide, zinc oxide, tin oxide, zirconium oxide, iron oxide, magnesium oxide, indium oxide, tungsten oxide, or When these mixtures are used, it is possible to display colors with excellent response speed of color development and decoloration. In particular, when titanium oxide is used, it is possible to display a color with an excellent response speed of color development and decoloration.

  The shape of the conductive or semiconductive fine particles is not particularly limited, but a shape having a large surface area per unit volume (hereinafter referred to as specific surface area) is used in order to efficiently carry the electrochromic compound. For example, when the fine particle is an aggregate of nanoparticles, it has a large specific surface area, so that the electrochromic compound is more efficiently supported and the display contrast ratio of color development and decoloration is excellent.

  The film thickness of the electrochromic layer 132 can be, for example, about 0.05 to 5.0 μm. When the film thickness of the electrochromic layer 132 is thinner than the above range, it is difficult to obtain the color density. Moreover, when the thickness of the electrochromic layer 132 is thicker than the above range, the manufacturing cost increases and the visibility is likely to decrease due to coloring. The electrochromic layer 132 and the conductive or semiconductive fine particle layer can be formed by vacuum film formation, but are preferably applied and formed as a particle-dispersed paste from the viewpoint of productivity.

  The insulating porous layer 133 is provided to electrically insulate the first electrode layer 131 and the second electrode layer 134 from each other. The insulating porous layer 133 is made of insulating metal oxide fine particles. Contains. The insulating porous layer 133 is provided to hold the electrolyte.

  The material of the insulating porous layer 133 is not particularly limited as long as it is a material that can form a porous layer. However, an organic material or an inorganic material that has high insulation and durability and excellent film forming properties, And their complexes are preferred.

  As a method of forming the insulating porous layer 133, for example, a sintering method (using fine holes or inorganic particles partially fused by adding a binder or the like to use holes generated between the particles) is used. be able to. As a method for forming the insulating porous layer 133, for example, an extraction method (after forming a constituent layer with an organic or inorganic substance soluble in a solvent and a binder that does not dissolve in the solvent, the organic or inorganic substance is dissolved in a solvent to To obtain holes) or the like.

The insulating porous layer 133 can be formed by a foaming method in which a polymer is foamed by heating or degassing, etc., and a mixture of polymers is phase-separated by operating a good solvent and a poor solvent. Forming methods such as a phase inversion method and a radiation irradiation method in which various radiations are radiated to form pores may be used. Specific examples include polymer mixed particle films containing metal oxide fine particles (such as SiO ₂ particles and Al ₂ O ₃ particles) and a polymer binder, porous organic films (such as polyurethane resins and polyethylene resins), and porous film shapes. An inorganic insulating material film formed in the above.

  The unevenness of the insulating porous layer 133 depends on the thickness of the second electrode layer 134. For example, when the thickness of the second electrode layer 134 is 100 nm, the surface roughness of the insulating porous layer 133 is as follows. Must satisfy the requirement of less than 100 nm in average roughness (Ra). When the average roughness exceeds 100 nm, the surface resistance of the second electrode layer 134 is greatly lost, which causes display defects. The film thickness of the insulating porous layer 133 can be, for example, about 0.5 to 2 μm.

  The insulating porous layer 133 is preferably used in combination with an inorganic film. This is because when the second electrode layer 134 formed on the surface of the insulating porous layer 133 is formed by sputtering, damage to the organic material of the insulating porous layer 133 or the electrochromic layer 132 as a lower layer is prevented. This is to reduce.

As the inorganic film, it is preferable to use a material containing ZnS in addition to SiO ₂ . ZnS has a feature that it can be deposited at high speed by sputtering without damaging the electrochromic layer 132 or the like. Furthermore, ZnS—SiO ₂ , ZnS—SiC, ZnS—Si, ZnS—Ge, or the like may be used as a material containing ZnS as a main component.

Here, the ZnS content is preferably about 50 to 90 mol% in order to maintain good crystallinity when the insulating layer is formed. Therefore, particularly preferred materials are ZnS—SiO ₂ (8/2), ZnS—SiO ₂ (7/3), ZnS, ZnS—ZnO—In ₂ O ₃ —Ga ₂ O ₃ (60/23/10/7). ). By using the above materials as the insulating porous layer 133, a good insulating effect can be obtained with a thin film, and a decrease in film strength and film peeling can be prevented.

  The deterioration preventing layer 135 has a chemical reaction opposite to that of the electrochromic layer 132, and balances the electric charge so that the first electrode layer 131 and the second electrode layer 134 are corroded or deteriorated by an irreversible oxidation-reduction reaction. It has the role of suppressing. As a result, the repeated stability of the electrochromic light control lens 10 can be improved. In addition, the reverse reaction includes acting as a capacitor in addition to the case where the degradation preventing layer is oxidized and reduced.

  The deterioration preventing layer 135 may be formed only on the upper surface of the insulating porous layer (the surface opposite to the surface on which the lens 120 is formed). In this case, since it is not necessary to form a deterioration preventing layer on the lower surface of the second electrode layer (the surface on which the lens 120 is formed), damage to the deterioration preventing layer caused by sputtering or the like when forming the second electrode layer. Can be reduced. The deterioration preventing layer may be formed only on the upper surface of the second electrode layer (the surface opposite to the surface on which the lens 120 is formed). In this case, ions contained in the electrolyte can be moved to the front and back of the second electrode layer 134 through the second electrode layer 134 having fine through holes. That is, the deterioration preventing layer 135 may be formed only on the upper surface of the insulating porous layer or only on the upper surface of the second electrode layer, but a structure capable of making the deterioration preventing layer more uniform is appropriately selected. It is preferable to do. If necessary, the deterioration preventing layer may be formed on both the upper surface of the second electrode layer and the lower surface of the second electrode layer.

  The material of the deterioration preventing layer 135 is not particularly limited as long as it is a material that plays a role of preventing corrosion of the first electrode layer 131 and the second electrode layer 134 due to an irreversible oxidation-reduction reaction. As the material of the deterioration preventing layer 135, for example, antimony tin oxide, nickel oxide, titanium oxide, zinc oxide, tin oxide, or a conductive or semiconductive metal oxide containing a plurality of them can be used. Furthermore, when coloring of the deterioration preventing layer does not become a problem, the same material as the above-described electrochromic material can be used.

  The deterioration preventing layer 135 can be composed of a porous thin film that does not hinder electrolyte injection. For example, conductive or semiconductive metal oxide fine particles such as antimony tin oxide, nickel oxide, titanium oxide, zinc oxide, tin oxide, etc., binders such as acrylic, alkyd, isocyanate, urethane, epoxy, phenol, etc. By fixing to the second electrode layer 34, a suitable porous thin film satisfying the electrolyte permeability and the function as a deterioration preventing layer can be obtained.

  Alternatively, as the material of the deterioration preventing layer 135, a material that maintains a transparent state with charge exchange may be used. For example, conductive polymers such as polypyrrole, polythiophene, polyaniline, or derivatives thereof, hybrid polymers of metal complexes and organic ligands, radical polymers, and the like can be given. When these are used, it is necessary to adjust the film density so as not to inhibit the injection of the electrolyte, or to form through holes by laser processing or the like. Alternatively, these materials may be used as the electrochromic layer 132, and the organic electrochromic compound supported on the conductive or semiconductive fine particles described above may be used as the deterioration preventing layer 135.

  As the deterioration preventing layer 135, it is preferable to use highly transparent n-type semiconducting oxide fine particles (n-type semiconducting metal oxide). As a specific example, titanium oxide, tin oxide, zinc oxide, or compound particles containing a plurality of them, or a mixture of particles having a primary particle size of 100 nm or less can be used.

  Furthermore, when these deterioration preventing layers 135 are used, the electrochromic layer 132 is preferably a material that changes from colored to transparent by an oxidation reaction. This is because the n-type semiconductor metal oxide is easily reduced (electron injection) at the same time as the electrochromic layer 132 undergoes an oxidation reaction, and the drive voltage can be reduced.

  In such a form, a particularly preferred electrochromic material is an organic polymer material. The film can be easily formed by a coating process or the like, and the color can be adjusted and controlled by the molecular structure. Examples of these organic polymer materials include poly (3,4-ethylenedioxythiophene) -based materials, bis (terpyridine) s and iron ion complex-forming polymers, and the like.

  As a method for forming the deterioration preventing layer 135, a vacuum deposition method, a sputtering method, an ion rating method, or the like can be used. If the material of the deterioration preventing layer 135 can be formed by coating, a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, a bar coating method, a roll coating method, a wire bar coating method, a dip coating method, Various printing methods such as a slit coating method, a capillary coating method, a spray coating method, a nozzle coating method, a gravure printing method, a screen printing method, a flexographic printing method, an offset printing method, a reverse printing method, and an inkjet printing method can be used.

  The protective layer 136 protects the device from external stress and chemicals in the cleaning process, prevents leakage of the electrolyte, and prevents intrusion of unnecessary substances such as moisture and oxygen in the atmosphere for stable operation of the electrochromic device. It has a role to prevent. At the same time, transparency, surface smoothness, refractive index, heat resistance, and light resistance are required so as not to impair the function as a lens. The thickness is preferably in the range of 1 μm to 200 μm.

  The protective layer 136 may be formed at least on the upper surface of the deterioration preventing layer 135 (surface opposite to the surface on which the lens 120 is formed). As shown in FIG. 7, the protective layer 136 is formed on each side of the first electrode layer 131, the electrochromic layer 132, the insulating porous layer 133, the second electrode layer 134, and the deterioration preventing layer 135. The side layer to be coated is not particularly limited.

  As a material for the protective layer 136, an ultraviolet curable resin or a thermosetting resin can be used. Specifically, an acrylic resin, a urethane resin, an epoxy resin, or the like is preferably used. As a process for forming the protective layer 36, various film forming methods such as a spin coating method, a dip coating method, a spray coating method, and a casting method can be used.

  An electrolyte (not shown) is used as an electrolyte solution through the deterioration prevention layer 135 through the fine through-holes formed in the second electrode layer 134 to form the first electrode layer 131 and the second electrode layer 134. The insulating porous layer 133 disposed therebetween is filled. That is, the electrolyte is filled between the first electrode layer 131 and the second electrode layer 134 so as to be in contact with the electrochromic layer 132 and is deteriorated through the through-hole formed in the second electrode layer 134. It is provided in contact with the prevention layer 135. As the electrolytic solution, a liquid electrolyte such as an ionic liquid or a solution obtained by dissolving a solid electrolyte in a solvent can be used.

As the electrolyte material, for example, inorganic ion salts such as alkali metal salts and alkaline earth metal salts, quaternary ammonium salts, acids, and alkali supporting salts can be used. Specifically, LiClO ₄ , LiBF ₄ , LiAsF ₆ , LiPF ₆ , LiCF ₃ SO ₃ , LiCF ₃ COO, KCl, NaClO ₃ , NaCl, NaBF ₄ , NaSCN, KBF ₄ , Mg (ClO ₄ ) ₂ , Mg ( BF ₄ ) ₂ or the like can be used.

  An ionic liquid can also be used. The ionic liquid may be any substance that is generally studied and reported. In particular, an organic ionic liquid has a molecular structure that exhibits a liquid in a wide temperature range including room temperature. Examples of molecular structures include cation components such as N, N-dimethylimidazole salt, N, N-methylethylimidazole salt, N, N-methylpropylimidazole salt, N, N-dimethylpyridinium salt, N, Examples thereof include aromatic salts such as pyridinium derivatives such as N-methylpropylpyridinium salts, and aliphatic quaternary ammonium systems such as tetraalkylammonium such as trimethylpropylammonium salt, trimethylhexylammonium salt, and triethylhexylammonium salt.

As the anion component, a compound containing fluorine is preferable in terms of stability in the atmosphere, and examples thereof include BF ₄ , CF ₃ SO ₃ —, PF ₄ —, (CF ₃ SO ₂ ) ₂ N—, and the like. An ionic liquid formulated by a combination of these cationic components and anionic components can be used.

  Examples of the solvent include propylene carbonate, acetonitrile, γ-butyrolactone, ethylene carbonate, sulfolane, dioxolane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, 1,2-dimethoxyethane, 1,2-ethoxymethoxyethane, polyethylene. Glycols, alcohols and mixed solvents thereof can be used.

  Further, the electrolytic solution need not be a low-viscosity liquid, and can take various forms such as a gel, a polymer cross-linked type, and a liquid crystal dispersed type. It is preferable to form the electrolyte in a gel or solid form from the viewpoint of improving element strength, improving reliability, and preventing color diffusion. As the solidification method, a method of holding the electrolyte and the solvent in the polymer resin is preferable. This is because high ionic conductivity and solid strength can be obtained. Further, it is preferable to use a photocurable resin as the polymer resin. This is because the device can be manufactured at a low temperature and in a short time compared to thermal polymerization or a method of thinning the film by evaporating the solvent.

  The electrochromic light control lens (see FIG. 7) having the above-described structure is a lens with excellent light resistance and high performance. The lens can be applied to electrochromic dimming glasses.

  FIG. 8 is a perspective view illustrating electrochromic dimming glasses 150 according to this embodiment. Referring to FIG. 8, the electrochromic dimming glasses 150 include an electrochromic dimming lens 151, a spectacle frame 152, a switch 153, and a power source 154. An electrochromic light control lens 151 shown in FIG. 8 is obtained by processing the electrochromic light control lens 110 shown in FIG. 7 into a desired shape.

  The two electrochromic dimming lenses 151 are incorporated in the spectacle frame 152. The eyeglass frame 152 is provided with a switch 153 and a power source 154. The power source 154 is electrically connected to the first electrode layer 131 and the second electrode layer 134 through a switch 153 and a wiring (not shown). By switching the switch 153, for example, one of a state in which a positive voltage is applied between the first electrode layer 131 and the second electrode layer 134, a state in which a negative voltage is applied, and a state in which no voltage is applied are selected. The state can be selected.

  As the switch 153, for example, an arbitrary switch such as a slide switch or a push switch can be used. However, it is limited to a switch that can switch at least the three states described above. As the power source 154, for example, an arbitrary DC power source such as a button battery or a solar battery can be used. The power source 154 can apply a voltage of about plus or minus several volts between the first electrode layer 131 and the second electrode layer 134.

  For example, by applying a positive voltage between the first electrode layer 131 and the second electrode layer 134, the two electrochromic light control lenses 151 are colored in a predetermined color. Further, when a negative voltage is applied between the first electrode layer 131 and the second electrode layer 134, the two electrochromic light control lenses 151 are decolored and become transparent.

  However, depending on the characteristics of the material used for the electrochromic layer 132, color is developed by applying a minus voltage between the first electrode layer 131 and the second electrode layer 134, and the color is erased by applying a plus voltage. However, it may be transparent. Note that once the color is developed, the color continues even if no voltage is applied between the first electrode layer 131 and the second electrode layer 134.

  By using the electrochromic light control lens 110 as the lens of the electrochromic light control glasses 150, the electrochromic light control glasses 150 having excellent light resistance and high performance can be realized.

(Embodiment 5)
In the present embodiment, an electrochromic light control lens was produced and evaluated for light resistance. As the electrochromic light control lens, two different types of electrochromic light control lenses were produced. That is, an electrochromic light control lens as an example and an electrochromic light control lens as a comparative example were produced.

<Production of electrochromic light control lens as an example>
First, an electrochromic light control lens as an example was manufactured.

[Formation of first electrode layer and electrochromic layer]
A lens having a diameter of 65 mm was prepared, and an ITO film having a thickness of about 100 nm was formed by sputtering on a 25 mm × 45 mm region and a lead portion through a metal mask to form the first electrode layer 131.

  Next, a dispersion of titanium oxide nanoparticles whose surface is coated with aluminum hydroxide on the surface of this ITO film (average particle diameter: about 20 nm, weight ratio of titanium oxide nanoparticles to aluminum hydroxide: 11.7%) is spin-coated. It was applied by the method. And the nanostructure semiconductor material which consists of an about 1.0 micrometer titanium oxide particle film was formed by performing an annealing process for 5 minutes at 120 degreeC.

  Subsequently, as an electrochromic compound, a 2,2,3,3-tetrafluoropropanol solution containing 1.5 wt% of the compound represented by the structural formula [Chemical Formula 2] was applied by a spin coating method. Thereafter, an annealing process was performed at 120 ° C. for 10 minutes to carry (adsorb) the titanium oxide particle film to form the electrochromic layer 32.

［絶縁性多孔質層、微細な貫通孔が形成された第２の電極層の形成］
続いて、エレクトロクロミック層１３２上に平均一次粒径２０ｎｍのＳｉＯ_２微粒子分散液（シリカ固形分濃度２４．８重量％、ポリビニルアルコール１．２重量％、水７４重量％）をスピンコートし、絶縁性多孔質層１３３を形成した。形成した絶縁性多孔質層１３３の膜厚は約２μｍであった。更に、平均一次粒径４５０ｎｍのＳｉＯ_２微粒子分散液（シリカ固形分濃度１重量％、２−プロパノール９９重量％）をスピンコートし、微細貫通孔形成用マスク（コロイダルマスク）を形成した。

[Formation of insulating porous layer, second electrode layer with fine through-holes]
Subsequently, a SiO ₂ fine particle dispersion liquid (silica solid content concentration 24.8% by weight, polyvinyl alcohol 1.2% by weight, water 74% by weight) having an average primary particle diameter of 20 nm is spin-coated on the electrochromic layer 132 and insulated. The porous layer 133 was formed. The film thickness of the formed insulating porous layer 133 was about 2 μm. Further, a fine SiO ₂ fine particle dispersion (silica solid content concentration 1 wt%, 2-propanol 99 wt%) having an average primary particle diameter of 450 nm was spin-coated to form a fine through-hole forming mask (colloidal mask).

Subsequently, an inorganic insulating layer of ZnS—SiO ₂ (8/2) was formed to a thickness of 40 nm on the fine through hole forming mask by a sputtering method. Further, an ITO film having a thickness of about 100 nm is formed on the inorganic insulating layer by a sputtering method in a region of 25 mm × 45 mm overlapping with the ITO film formed by the first electrode layer 131 and in a region different from the first electrode layer 131. A second electrode layer 134 was formed using a mask. Note that the ITO film formed in a region different from the first electrode layer 131 is a lead-out portion of the second electrode layer 134.

Thereafter, 2-in-propanol performs ultrasonic irradiation for 3 minutes, subjected to SiO ₂ removal treatment of the fine particles of 450nm is colloidal masks. It was confirmed by SEM observation that the second electrode layer 134 in which minute through holes of about 250 nm were formed was formed. The sheet resistance of the second electrode layer 134 was about 100Ω / □.

[Formation of deterioration prevention layer]
Subsequently, an antimony tin oxide particle dispersion was applied as a deterioration preventing layer 135 on the second electrode layer 134 by a spin coating method. And the nanostructure semiconductor material which consists of about 1.0 micrometer antimony tin oxide particle film was formed by performing an annealing process for 15 minutes at 120 degreeC.

[Electrolyte filling]
A solution obtained by mixing tetrabutylammonium perchlorate as an electrolyte and dimethyl sulfoxide and polyethylene glycol (molecular weight: 200) as a solvent in a ratio of 12:54:60 was used as an electrolytic solution. The element formed up to the deterioration preventing layer 135 was immersed for 1 minute and then dried on a hot plate at 120 ° C. for 1 minute to fill the electrolyte.

[Formation of protective layer]
Further, a protective layer 136 was formed to a thickness of about 3 μm by spin-coating an ultraviolet curable adhesive (trade name: manufactured by SD-17 DIC) and curing it by irradiation with ultraviolet light. This obtained the electrochromic light control lens as an Example.

<Production of electrochromic light control lens as comparative example>
Next, an electrochromic light control lens as a comparative example was produced.

  An electrochromic light control lens was produced in the same manner as in the example. However, the surface of the titanium oxide nanoparticles (average particle size: about 20 nm) contained in the electrochromic layer was not covered with metal hydroxide or the like at all.

(Light resistance evaluation of electrochromic light control lens)
The light resistance of two different electrochromic light control lenses was evaluated from the color difference retention rate. (Evaluation was performed in the same manner as in Examples 1 to 4 and Comparative Example 1). The evaluation results are shown in FIG.

  As shown in FIG. 9, in the electrochromic light control lens of the example, the color difference ΔE_α before light irradiation was 53.7. The color difference ΔE_β after light irradiation was 37.7.

  That is, when the surface of the titanium oxide particles contained in the electrochromic layer was coated with aluminum hydroxide, the color difference retention rate after light irradiation was 70.2%.

  As shown in FIG. 9, in the electrochromic light control lens of the comparative example, the color difference ΔE_α before the light irradiation was 53.9. Further, the color difference ΔE_β after light irradiation was 10.1.

  That is, when the surface of the titanium oxide particles contained in the electrochromic layer was not covered with a metal hydroxide or the like (for example, aluminum hydroxide), the color difference retention rate after light irradiation was 18.7%.

  From the above, it is suggested that an electrochromic light control lens having excellent light resistance can be realized by coating the surface of the titanium oxide nanoparticles contained in the electrochromic layer with a metal hydroxide.

  The preferred embodiment of the present invention has been described in detail above, but the present invention is not limited to the specific embodiment, and within the scope of the gist of the embodiment of the present invention described in the claims, Various modifications and changes are possible.

20 Electrochromic display element
21 Display board
22, 25, 28 Display electrode
23, 26, 29 Electrochromic layer
23b Titanium oxide particles
23c metal hydroxide
30 Electrolyte layer
31 White reflective layer
32 Charge retention layer
33 Counter electrode
35 Counter substrate
100 Information equipment (electronic book reader)
101 display
102 Control device (main controller)
110 Electrochromic light control lens
113 Display controller
114 VRAM

JP 2003-121883 A JP 2006-106669 A JP 2010-33016 A JP 2012-137736 A JP 2011-128200 A

Claims (14)

A display substrate, a display electrode, an electrochromic layer provided in contact with the display electrode, a counter substrate provided in opposition to the display substrate, a counter electrode, and a charge provided in contact with the counter electrode An electrochromic display element having a holding layer and an electrolyte layer filling a space between the display substrate and the counter substrate,
The electrochromic display element, wherein the surface of the titanium oxide particles contained in the electrochromic layer is coated with a metal hydroxide. A display substrate, a display electrode, an electrochromic layer provided in contact with the display electrode, a counter substrate provided in opposition to the display substrate, a counter electrode, and a charge provided in contact with the counter electrode An electrochromic display element having a holding layer, a white reflective layer provided between the electrochromic layer and the charge holding layer, and an electrolyte layer filling a space between the display substrate and the counter substrate. ,
The electrochromic display element in which the surface of the titanium oxide particles contained in the electrochromic layer and the white reflective layer is coated with a metal hydroxide.   The electrochromic display element according to claim 1, wherein the metal hydroxide is aluminum hydroxide.   A display comprising: the electrochromic display element according to any one of claims 1 to 3; a VRAM that stores display data; and a display controller that controls the electrochromic display element based on the display data. apparatus.   An information device comprising: the display device according to claim 4; and a control device that controls information displayed on the display device. Forming a display electrode on the display substrate;
Forming an electrochromic layer including titanium oxide particles whose surface is coated with a metal hydroxide on the display electrode;
Forming a counter electrode on the counter substrate;
Forming a charge retention layer on the counter electrode;
And a step of bonding the display substrate and the counter substrate through an electrolyte layer. Forming a display electrode on the display substrate;
Forming an electrochromic layer including titanium oxide particles whose surface is coated with a metal hydroxide on the display electrode;
Forming a white reflective layer containing titanium oxide particles whose surface is coated with a metal hydroxide on the electrochromic layer;
Forming a drive element layer on the counter substrate;
Forming a counter electrode on the drive element layer;
Forming a charge retention layer on the counter electrode;
And a step of bonding the display substrate and the counter substrate through an electrolyte layer. Forming a first display electrode on the display substrate;
Forming a first electrochromic layer including titanium oxide particles whose surface is coated with a metal hydroxide on the first display electrode;
Forming a first insulating layer on the first electrochromic layer;
Forming a second display electrode on the first insulating layer;
Forming a second electrochromic layer including titanium oxide particles whose surface is coated with a metal hydroxide on the second display electrode;
Forming a second insulating layer on the second electrochromic layer;
Forming a third display electrode on the second insulating layer;
Forming a third electrochromic layer including titanium oxide particles whose surface is coated with a metal hydroxide on the third display electrode;
Forming a white reflective layer including titanium oxide particles whose surface is coated with a metal hydroxide on the third electrochromic layer;
Forming a drive element layer on the counter substrate;
Forming a counter electrode on the drive element layer;
Forming a charge retention layer on the counter electrode;
And a step of bonding the display substrate and the counter substrate through an electrolyte layer. A lens, and a first electrode layer provided in contact with the lens;
An electrochromic layer provided in contact with the first electrode layer;
An insulating porous layer provided in contact with the electrochromic layer;
A deterioration preventing layer provided in contact with the insulating porous layer;
A second electrode layer provided in contact with the deterioration preventing layer;
An electrolyte layer that fills a space between the first electrode layer and the second electrode layer and is in contact with the electrochromic layer and the deterioration preventing layer via the insulating porous layer;
The electrochromic light control lens, wherein the surface of the titanium oxide particles contained in the electrochromic layer is coated with a metal hydroxide. A lens, and a first electrode layer provided in contact with the lens;
An electrochromic layer provided in contact with the first electrode layer;
An insulating porous layer provided in contact with the electrochromic layer;
A second electrode layer provided in contact with the insulating porous layer;
A deterioration preventing layer provided in contact with the second electrode layer;
An electrolyte layer filling the space between the first electrode layer and the second electrode layer and contacting the electrochromic layer and the deterioration preventing layer via the insulating porous layer and the second electrode layer And having
The electrochromic light control lens, wherein the surface of the titanium oxide particles contained in the electrochromic layer is coated with a metal hydroxide.   The electrochromic light control lens according to claim 9 or 10, wherein the deterioration preventing layer is formed on both surfaces of the second electrode layer. A lens, and a first electrode layer provided in contact with the lens;
A deterioration preventing layer provided in contact with the first electrode layer;
An insulating porous layer provided in contact with the deterioration preventing layer;
An electrochromic layer provided in contact with the insulating porous layer;
A second electrode layer provided in contact with the electrochromic layer;
An electrolyte layer that fills a space between the first electrode layer and the second electrode layer and is in contact with the electrochromic layer and the deterioration preventing layer via the insulating porous layer;
The electrochromic light control lens, wherein the surface of the titanium oxide particles contained in the electrochromic layer is coated with a metal hydroxide. A lens, and a first electrode layer provided in contact with the lens;
A deterioration preventing layer provided in contact with the first electrode layer;
An insulating porous layer provided in contact with the deterioration preventing layer;
A first electrochromic layer provided in contact with the insulating porous layer;
A second electrode layer provided in contact with the first electrochromic layer;
A second electrochromic layer provided in contact with the second electrode layer;
The space between the first electrode layer and the second electrode layer is filled, and the first electrochromic layer and the second electrochromic layer are interposed via the insulating porous layer and the second electrode layer. And an electrolyte layer in contact with the deterioration preventing layer,
The electrochromic light control lens, wherein the surface of the titanium oxide particles contained in the electrochromic layer is coated with a metal hydroxide.   The electrochromic light control lens according to any one of claims 9 to 13, wherein the metal hydroxide is aluminum hydroxide.

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