JP5783044B2 - Display element - Google Patents

Description

  The present invention relates to an electrochemical display element that enables multicolor display.

  2. Description of the Related Art In recent years, various types of display elements called electronic paper have been proposed that perform reflective display that is easy to carry and easy to read, such as paper, with a display method different from liquid crystal displays and CRT displays. As such an electronic paper, there is a demand for a display element having a wide color reproduction range display capable of bright white display and full color display and a high durability for repeated rewriting.

  An electrochromic display element has attracted attention as a method capable of performing color display. For example, Patent Document 1 discloses a method of laminating a plurality of electrochromic layers via a transparent thin film transistor and performing multicolor display. Patent Document 2 discloses a multilayer display element that does not include a thin film transistor. In any of the methods, the structure has a transparent electrode for driving the electrochromic layer between layers to perform color display. However, the transparent electrode generally has a visible light transmittance of about 80 to 88%, and when a plurality of the transparent electrodes are stacked, the electrochromic layer disposed in the lower layer becomes dark. For this reason, it is difficult to obtain a bright white display characteristic as a whole display element, and as a result, there is a problem that the color reproduction range becomes narrow. Further, the display element having the above configuration is not sufficiently satisfactory with respect to durability of repeated display.

JP 2007-41259 A JP 2005-535930 A

  The present invention has been made in view of the above problems, and its object is to provide a display element for electronic paper having high color reflectance, excellent color reproducibility, and good durability against repeated rewriting. is there.

  The above object of the present invention is achieved by the following configurations.

1. In an electrochromic display element having at least an electrode provided in a predetermined pattern on a single substrate and an electrochromic layer, the electrode is composed of a pair of electrodes arranged at opposing positions on the same plane. A pixel electrode forming one pixel, and by causing a potential difference between the pair of electrodes, the electrochromic layer is colored or decolored , and
A display element comprising an electrically insulating bank between a pair of the pixel electrodes forming one pixel and the other pixel electrodes .

  2. 1. The structure according to 1 above, wherein two or more electrochromic display units each composed of an electrode and an electrochromic layer provided in a predetermined pattern are stacked on the one substrate. The display element as described.

  3. 3. The display element according to 1 or 2 above, which has a white scattering layer.

4 . 4. The display element according to any one of 1 to 3 , wherein the electrochromic layer has a nanoporous layer.

5 . 5. The display element according to any one of 1 to 4 , wherein the electrochromic layer contains a compound represented by the following general formula (L) as an electrochromic compound.

[Wherein, Rl ₁ represents a substituted or unsubstituted aryl group, and Rl ₂ and Rl ₃ each represent a hydrogen atom or a substituent. X represents> N—Rl ₄ , an oxygen atom or a sulfur atom, and Rl ₄ represents a hydrogen atom or a substituent. ]
6 . 6. The display device according to 5 above, wherein the compound represented by the general formula (L) is a compound represented by the following general formula (L2).

[Wherein, R ₂₁ and R ₂₂ each represents an aliphatic group, an aliphatic oxy group, an acylamino group, a carbamoyl group, an acyl group, a sulfonamido group, or a sulfamoyl group, and R l ₂₃ represents an aromatic group or an aromatic heterocyclic ring. Rl ₂₄ represents a hydrogen atom, an aliphatic group, an aromatic group or an aromatic heterocyclic group, and Rl ₂₅ represents a hydrogen atom, an aliphatic group, an aromatic group or an acyl group. ]
7 . Any one of 1 to 6 above, wherein at least one of the electrochromic layers contains a metal species that can be electrically dissolved or deposited to display substantially transparent and black for visible light. The display element according to claim 1.

8 . When observed from the viewing side, the total area of the colored region for performing colored display composed of the electrode pairs arranged on the same plane on the same plane is 70% or more of the entire display region, The display element according to any one of 1 to 7 , wherein:

9 . When the thickness of the electrochromic layer is T (μm) and the distance between the corresponding electrode pairs is L (μm), L / T is 2.5 or more and 10.0 or less. 9. The display element according to any one of 1 to 8 .

  According to the present invention, it is possible to provide a display element for electronic paper having high color reflectance, excellent color reproducibility, and good durability against repeated rewriting.

It is a schematic sectional drawing which shows an example of the single electrochromic display unit comprised from the opposing image electrode and electrochromic layer which are arrange | positioned on the same board | substrate. It is a schematic sectional drawing which shows an example of the display element which consists of a structure which laminated | stacked two layers of electrochromic display units comprised from the opposing image electrode and electrochromic layer which are arrange | positioned on the same board | substrate. It is a schematic sectional drawing which shows an example of the display element which has a white scattering layer for performing a white display, and consists of a structure which laminated | stacked two layers of electrochromic display units. It is a schematic sectional drawing which shows an example of the electrochromic display unit which has a bank which electrically partitions adjacent pixels. 2 is a schematic cross-sectional view showing an example of an electrochromic display unit having a nanoporous layer 6. FIG. It is the top view which showed an example of the shape of a pixel electrode, and arrangement | positioning on a board | substrate. It is the top view which showed the other example of the shape of a pixel electrode, and arrangement | positioning on a board | substrate. It is the top view which showed the other example of the shape of a pixel electrode, and arrangement | positioning on a board | substrate. It is a schematic sectional drawing which shows an example of the electrochromic display unit structure connected to the circuit for a display element drive through the contact hole. FIG. 5 is a schematic top view showing a colored region for the entire display region in a display element including a plurality of pixel electrodes. The thickness T of the electrochromic layer and the distance L between the electrodes are shown. An example of a display element having a conventional configuration is shown, which is a display element having a configuration in which a transparent electrode covers the entire pixel.

  Hereinafter, embodiments for carrying out the present invention will be described in detail.

  As a result of intensive studies in view of the above problems, the inventor of the present invention, in an electrochromic display element having at least an electrode provided in a predetermined pattern and an electrochromic layer on one substrate, The pixel electrode is composed of a pair of electrodes arranged at opposing positions on the same plane and forms one pixel, and the electrochromic layer is colored or decolored by generating a potential difference between the pair of electrodes. The present invention has found that a display element for electronic paper having high color reflectivity, excellent color reproducibility, and good durability against repeated rewriting can be realized by the display element characterized by the above. It depends on you.

  Details of the display element of the present invention will be described below.

<< Display element configuration >>
First, the basic configuration of the display element of the present invention will be described with reference to the drawings. However, the configuration of the display element of the present invention is not limited to the configuration exemplified here.

  The display element of the present invention has an electrochromic display unit including a pair of image electrodes disposed at opposite positions on the same substrate and an electrochromic layer sandwiched between the image electrodes. It is characterized by being.

  FIG. 1 is a schematic cross-sectional view showing an example of a single electrochromic display unit composed of an image electrode pair and an electrochromic layer disposed on the same substrate.

  In the display element shown in FIG. 1, electrodes 3A, 3A ′, 3B, 3B ′, 3C, and 3C ′ are formed on a substrate 1 in a predetermined pattern, and an electrochromic layer 2 is provided so as to cover the electrodes. . The electrodes 3A and 3A ', 3B and 3B', 3C and 3C 'are a pair of electrode pairs, and the electrochromic layer displayed as a region A sandwiched between these electrode pairs is one pixel. In the configuration shown in FIG. 1, a predetermined distance B is provided between each electrode pair in order to eliminate the influence of adjacent electrodes. By applying a potential difference between the electrodes 3A and 3A ', between 3B and 3B', and between 3C and 3C ', the electrochromic layer 2 of the pixel portion (region A) is colored and decolored to display an image. The

  FIG. 2 is a schematic cross-sectional view showing an example of a display element having a configuration in which two electrochromic display units each composed of an image electrode pair and an electrochromic layer arranged on the same substrate are stacked.

  The display element shown in FIG. 2 has a configuration in which two layers of electrochromic display units having the configuration described in FIG. 1 are stacked one above the other, and the upper side of the drawing is described as the viewing direction.

  In the display element of the present invention, when the electrochromic display unit is configured to overlap as shown in FIG. 2, the substrate 1-1 of the upper electrochromic display unit displays the color of the electrochromic display unit disposed in the lower layer. It is preferable that it has high light transmittance so that it can browse. Although not shown in FIG. 2, a transparent substrate can be provided on the electrochromic layer 2-1 for the purpose of protecting the display element or improving the handleability. Here, a yellow-colored electrochromic layer, a magenta-colored electrochromic layer, a cyan-colored electrochromic layer, and a black display layer made of a metal material, a yellow-colored electrochromic layer, a magenta-colored electrochromic layer, It is preferable that a layer and a cyan-colored electrochromic layer are stacked, and at least one of these three-color electrochromic layers further includes a black display object made of metal.

  FIG. 3 is a schematic cross-sectional view showing an example of a display element having a configuration in which a white scattering layer for performing white display is provided and two electrochromic display units are stacked.

  FIG. 3 shows a shape in which a transparent substrate 1 ′ is provided above the electrochromic layer 2-1 of the upper electrochromic display unit. In FIG. 3, the white scattering layer 4 includes the substrate 1-2, the electrode group 3-2 (3A, 3A ′, 3B, 3B ′, 3C, 3C ′) and the electrochromic layer of the electrochromic display unit located in the lower layer. 2 is provided between the electrode group 3-2 and the electrochromic layer 2-2. It can also be provided outside the substrate 1-2. In that case, it is preferable that the lowermost substrate 1-2 has high light transmittance.

  FIG. 4 is a schematic cross-sectional view showing an example of an electrochromic display unit having a bank 5 that electrically separates adjacent pixels.

  The height of the bank 5 applicable to the present invention is preferably higher than that of the electrodes, and may be a partition shape that completely separates pixels. The bank 5 may be formed by applying an insulating thermoplastic resin or ultraviolet curable resin on the substrate, masking the bank pattern on the substrate, curing the resin with heat or light, and then uncured portions. And a method of forming a bank pattern by embossing and curing. In addition to the trapezoid illustrated in FIG. 4, various shapes of banks can be applied as the shape of the bank according to the present invention depending on the purpose and effect.

  FIG. 5 is a schematic cross-sectional view showing an example of an electrochromic display unit having the nanoporous layer 6.

  The configuration of the display element shown in FIG. 5 shows an example of a display element having a configuration in which two layers of electrochromic display units are stacked as in FIG. This is an example in which nanoporous layers 6-1 and 6-2 having a large number of nano-sized pores in the layer are formed.

  Although details of the nanoporous layer will be described later, it is desirable that the nanoporous layer according to the present invention be substantially transparent in the electrochromic layer. Examples of the material for forming such a nanoporous layer include glass, polymethyl methacrylate (PMMA), tin oxide, zinc oxide, zirconium, silica, and the like. Can be used.

  6 to 8 are top views showing an example of the shape of the pixel electrode and the arrangement on the substrate.

  The configuration shown in FIG. 6 is an example in which a pair of opposed image electrodes 3A and 3A ′, 3B and 3B ′, 3C and 3C ′, 3D and 3D ′ are all arranged in the same direction, and FIG. 3A and 3A ′, 3D and 3D ′ are in the same direction, and image electrodes 3B and 3B ′, 3C and 3C ′ are arranged at positions orthogonal to them. The shape and arrangement of the pixel electrode shown in FIG. 8 is an example in which the shape of the electrode is changed to an L shape with respect to the arrangement shown in FIG.

  In the display element of the present invention, as shown in FIG. 9, it can be connected to a display element driving circuit through a contact hole 7 or the like.

  FIG. 9 is a schematic cross-sectional view showing an example of the configuration of the electrochromic display unit connected to the display element driving circuit via the contact hole 7.

  The electrode patterns of the laminated electrochromic display units do not have to be the same, and it is more preferable that they are arranged so as not to overlap each other to the extent that the contact hole 7 can be provided. FIG. 9 shows an example in which the display elements having electrodes arranged as shown in FIG. 6 or FIG. 7 are stacked so that the electrode directions do not all coincide.

  The contact hole referred to in the present invention is an opening for connecting the display unit and the drive circuit wiring layer, and can be formed by lithography and etching techniques in the same manner as a general semiconductor element.

  FIG. 10 is a schematic top view showing a colored region with respect to the entire display region in a display element including a plurality of pixel electrodes.

  In FIG. 10, the whole composed of four pixels is the entire display area, and the colored area 8 is an area between the pixel electrodes. In the display element of the present invention, it is preferable that the total area of the colored regions for performing colored display composed of electrode pairs arranged at opposing positions on the same plane is 70% or more of the entire display region.

  FIG. 11 shows the thickness T of the electrochromic layer and the distance L between the electrodes.

  In the display element of the present invention, when the thickness of the electrochromic layer is T (μm) and the distance between the corresponding electrode pairs is L (μm), L / T is 2.5 or more and 10.0 or less. It is preferable that

  FIG. 12 shows an example of a display element having a conventional configuration, which is a display element having a configuration in which the transparent electrode 9 covers the entire pixel.

  Next, details of each component of the display element of the present invention will be described.

〔substrate〕
Of the pair of substrates used in the display element of the present invention, the substrate located on the viewing side is preferably a substantially transparent substrate. The substantially transparent substrate referred to in the present invention is a substrate having a transmittance for visible light of at least 85% or more, more preferably 90% or more.

  Examples of transparent substrates applicable to the present invention include polyester (for example, polyethylene terephthalate), polyimide, polymethyl methacrylate, polystyrene, polypropylene, polyethylene, polyamide, nylon, polyvinyl chloride, polyvinylidene chloride, polycarbonate, and polyether sulfone. , Silicon resin, polyacetal resin, fluororesin, cellulose derivative, polymer film such as polyolefin, plate substrate, glass substrate and the like.

  In the case of a transmissive display element, it is desirable that the opposing substrate be a substantially transparent base material in addition to the substrate located on the viewing side.

  Conversely, in the case of a reflective display element, a configuration in which the counter substrate itself is white can be applied. As a white board | substrate, various board | substrates currently marketed as a white reflective board | substrate for LED, void PET (polyethylene terephthalate), etc. other than an epoxy resin board | substrate etc. can be used. In another embodiment, a white pigment can be applied to the outside of the transparent counter substrate, or the white substrate can be bonded. Further, when the white scattering layer is formed on the display element side from the counter substrate, the counter substrate may be an opaque substrate such as an inorganic substrate such as a metal substrate or a ceramic substrate.

(White scattering layer)
The display element of the present invention preferably has a white scattering layer as shown in FIG.

  In the display element of the present invention, when the white scattering layer is formed inside the counter substrate as shown in FIG. 3, the white scattering layer is not substantially dissolved in the material forming the electrochromic layer. Is preferred. Specifically, it can be formed by applying and drying an aqueous mixture of an aqueous polymer and a white pigment.

  Examples of the white pigment applicable to the present invention include titanium dioxide (anatase type or rutile type), barium sulfate, calcium carbonate, aluminum oxide, zinc oxide, magnesium oxide and zinc hydroxide, magnesium hydroxide, magnesium phosphate, Magnesium hydrogen phosphate, alkaline earth metal salt, talc, kaolin, zeolite, acidic clay, glass, organic compounds such as polyethylene, polystyrene, acrylic resin, ionomer, ethylene-vinyl acetate copolymer resin, benzoguanamine resin, urea-formalin resin, A melamine-formalin resin, a polyamide resin, etc. can be mentioned, You may use it in the state which has the void which changes a refractive index in single-piece | unit or composite mixture, or particle | grains.

In the present invention, among the white particles, titanium dioxide, zinc oxide, and zinc hydroxide are preferably used. In addition, titanium dioxide surface-treated with inorganic oxides (Al ₂ O ₃ , AlO (OH), SiO _2, etc.), in addition to these surface treatments, trimethylolethane, triethanolamine acetate, trimethylcyclosilane, etc. Titanium dioxide subjected to organic treatment can be used.

  Of these white particles, it is more preferable to use titanium oxide or zinc oxide from the viewpoint of coloring prevention at high temperature and the reflectance of the element due to the refractive index.

  In the present invention, examples of the aqueous polymer that does not substantially dissolve in the solvent of the electrochromic medium include water-soluble polymers and polymers dispersed in an aqueous solvent.

Examples of water-soluble polymers include proteins such as gelatin and gelatin derivatives, cellulose derivatives, natural compounds such as starch, gum arabic, dextran, pullulan, and carrageenan, and the like, polyvinyl alcohol, polyvinyl pyrrolidone, acrylamide polymers, and the like. And synthetic polymer compounds such as derivatives thereof. Examples of gelatin derivatives include acetylated gelatin, phthalated gelatin, polyvinyl alcohol derivatives include terminal alkyl group-modified polyvinyl alcohol, terminal mercapto group-modified polyvinyl alcohol, and cellulose derivatives include hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, and the like. It is done. Further, Research Disclosure and those described on pages (71) to (75) of JP-A No. 64-13546, US Pat. No. 4,960,681, JP-A No. 62-245260, etc. superabsorbent polymers described, namely -COOM or -SO 3 M _(M is a hydrogen atom or an alkali metal) homopolymer or a vinyl monomer together or with other vinyl monomers of the vinyl monomer having a (e.g., sodium methacrylate, Copolymers with ammonium acid, potassium acrylate, etc.) are also used. Two or more of these binders can be used in combination.

  In the present invention, gelatin and gelatin derivatives, or polyvinyl alcohol or derivatives thereof can be preferably used.

  Polymers dispersed in an aqueous solvent include latexes such as natural rubber latex, styrene butadiene rubber, butadiene rubber, nitrile rubber, chloroprene rubber, isoprene rubber, polyisocyanate, epoxy, acrylic, silicon, polyurethane, Examples thereof include a thermosetting resin in which urea, phenol, formaldehyde, epoxy-polyamide, melamine, alkyd resin, vinyl resin and the like are dispersed in an aqueous solvent. Of these polymers, it is preferable to use an aqueous polyurethane resin described in JP-A-10-76621.

  In the present invention, the fact that it does not substantially dissolve in the material contained in the electrochromic layer means that the amount of dissolution per kg of material of the electrochromic layer is 0 g or more and 10 g or less at a temperature of −20 ° C. to 120 ° C. The amount of dissolution can be determined by a known method such as mass measurement, component quantification by liquid chromatogram or gas chromatogram.

  In the present invention, the water mixture of the water-based polymer and the white pigment is preferably in the form in which the white pigment is dispersed in water according to a known dispersion method. The mixing ratio of the water-based polymer / white pigment is preferably 1 to 0.01, more preferably 0.3 to 0.05 in terms of volume ratio.

  In the present invention, the medium for applying the water mixture of the water-based polymer and the white pigment may be at any position as long as it is on the component between the counter electrodes of the display element, but at least one electrode surface of the counter electrode It is preferable to apply on top. As a method for applying to a medium, for example, a coating method, a liquid spraying method, a spraying method via a gas phase, a method of flying droplets using vibration of a piezoelectric element, for example, a piezoelectric inkjet head, Examples thereof include a bubble jet (registered trademark) type ink jet head that causes droplets to fly using a thermal head that uses bumping, and a spray type that sprays liquid by air pressure or liquid pressure.

  The coating method can be appropriately selected from known coating methods. For example, an air doctor coater, blade coater, rod coater, knife coater, squeeze coater, impregnation coater, reverse roller coater, transfer roller coater, curtain coater, double coater Examples include roller coaters, slide hopper coaters, gravure coaters, kiss roll coaters, bead coaters, cast coaters, spray coaters, calendar coaters, and extrusion coaters.

  The water mixture of the water-based polymer and the white pigment applied on the medium may be dried by any method as long as water can be evaporated. For example, heating from a heat source, a heating method using infrared light, a heating method using electromagnetic induction, and the like can be given. Further, water evaporation may be performed under reduced pressure.

  In the display element of the present invention, it is desirable to carry out a curing reaction of the water-based compound with a curing agent during or after applying and drying the water mixture described above.

  Examples of the hardener used in the present invention include, for example, U.S. Pat. No. 4,678,739, column 41, 4,791,042, JP-A-59-116655, and 62-245261. No. 61-18942, 61-249054, 61-245153, JP-A-4-218044, and the like. More specifically, aldehyde hardeners (formaldehyde, etc.), aziridine hardeners, epoxy hardeners, vinyl sulfone hardeners (N, N'-ethylene-bis (vinylsulfonylacetamide) Ethane, etc.), N-methylol hardeners (dimethylolurea, etc.), boric acid, metaboric acid or polymer hardeners (compounds described in JP-A-62-234157). When gelatin is used as the aqueous compound, it is preferable to use a vinyl sulfone type hardener or a chlorotriazine type hardener alone or in combination. Moreover, when using polyvinyl alcohol, it is preferable to use boron-containing compounds such as boric acid and metaboric acid.

  These hardeners are used in an amount of 0.001 to 1 g, preferably 0.005 to 0.5 g, per 1 g of the aqueous compound. In addition, it is possible to perform heat treatment and humidity adjustment during the curing reaction in order to increase the film strength.

〔electrode〕
In the display element of the present invention, any electrode can be used without limitation as long as it exhibits high conductivity. In particular, a metal electrode is preferable because it exhibits high conductivity. As the metal electrode, for example, known metal species such as platinum, gold, silver, copper, aluminum, zinc, nickel, titanium, bismuth, and alloys thereof can be used. As an electrode manufacturing method, an existing method such as an evaporation method, a printing method, an ink jet method, a spin coating method, or a CVD method can be used.

  The transparent electrode is not particularly limited as long as it is transparent and conducts electricity. For example, Indium Tin Oxide (ITO: Indium Tin Oxide), Indium Zinc Oxide (IZO: Indium Zinc Oxide), Fluorine Doped Tin Oxide (FTO), Indium Oxide, Zinc Oxide, Platinum, Gold, Silver, Rhodium, Copper, Examples thereof include chromium, carbon, aluminum, silicon, amorphous silicon, and BSO (Bismuth Silicon Oxide). In order to form the electrode in this manner, for example, an ITO film may be vapor-deposited on the substrate by a sputtering method or the like, or an ITO film may be formed on the entire surface and then patterned by a photolithography method. The surface resistance value is preferably 100Ω / □ or less, and more preferably 10Ω / □ or less. The thickness of the transparent electrode is not particularly limited, but is generally 0.1 to 20 μm.

  In the display element of the present invention, since the electrodes for driving are formed on the same plane, when there is a plurality of pixels and high-definition display is required, in order to prevent a short circuit between adjacent pixels, a predetermined number is used. It is necessary to separate the pixels by this means. The simplest separation means is to provide a predetermined distance between the pixels. A more effective separation means is to provide an electrically insulating bank between the pixels as illustrated in FIG. The bank illustrated in FIG. 4 has a trapezoidal shape, but the shape is not limited thereto. The height of the bank is preferably higher than that of the electrode, and may be a partition shape that completely separates pixels. The bank can be formed by applying an insulating thermoplastic or ultraviolet curable resin on the substrate, masking the bank pattern on the substrate, curing it with heat or light, and removing the uncured part. There is a method in which a bank pattern is formed and cured.

[Electrochromic layer]
The electrochromic layer constituting the display element of the present invention contains at least an electrochromic compound. The electrochromic compound can itself be a solid layer, or it can form a layer as a liquid phase dissolved in a solution. Furthermore, it can also be a gel-like layer.

[Electrochromic compound]
The electrochromic compound applicable to the present invention is not particularly limited as long as it exhibits an action of color development or decoloration by at least one of electrochemical oxidation reaction and reduction reaction, and can be appropriately selected according to the purpose. .

  Examples of such electrochromic compounds include tungsten oxide, iridium oxide, nickel oxide, cobalt oxide, vanadium oxide, molybdenum oxide, titanium oxide, indium oxide, chromium oxide, manganese oxide, Prussian blue, indium nitride, tin nitride, and nitride nitride chloride. In addition to inorganic compounds such as zirconium, organometallic complexes, conductive polymer compounds, and organic dyes are known.

  Organic dyes used as electrochromic compounds include pyridinium compounds such as viologen, azine dyes such as phenothiazine, styryl dyes, anthraquinone dyes, pyrazoline dyes, fluorane dyes, donor / acceptor compounds (for example, tetracyano) Quinodimethane, tetrathiafulvalene) and the like. In addition, compounds known as redox indicators and pH indicators can also be used. These electrochromic compounds are described in “Application of Functional Dye” by Masahiro Irie and published by CMC Publishing.

  In the present invention, it is particularly preferable to use an electrochromic compound represented by the following general formula (L) from the viewpoints of coloration wavelength selectivity and memory properties.

In the general formula (L), Rl ₁ represents a substituted or unsubstituted aryl group, and Rl ₂ and Rl ₃ each represent a hydrogen atom or a substituent. X represents> N—Rl ₄ , an oxygen atom or a sulfur atom, and Rl ₄ represents a hydrogen atom or a substituent.

When Rl ₁ represents an aryl group having a substituent, the substituent is not particularly limited, and examples thereof include the following substituents.

  Alkyl groups (eg, methyl, ethyl, propyl, isopropyl, tert-butyl, pentyl, hexyl, etc.), cycloalkyl groups (eg, cyclohexyl, cyclopentyl, etc.), alkenyl groups, cycloalkenyl groups , Alkynyl groups (for example, propargyl group), glycidyl groups, acrylate groups, methacrylate groups, aromatic groups (for example, phenyl group, naphthyl group, anthracenyl group, etc.), heterocyclic groups (for example, pyridyl group, thiazolyl group, oxazolyl group) Group, imidazolyl group, furyl group, pyrrolyl group, pyrazinyl group, pyrimidinyl group, pyridazinyl group, selenazolyl group, sriphoranyl group, piperidinyl group, pyrazolyl group, tetrazolyl group, etc.), alkoxy group (for example, methoxy group, ethoxy group, propyloxy) Group, pliers Oxy group, cyclopentyloxy group, hexyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, etc.) , Aryloxycarbonyl group (for example, phenyloxycarbonyl group), sulfonamide group (for example, methanesulfonamide group, ethanesulfonamide group, butanesulfonamide group, hexanesulfonamide group, cyclohexanesulfonamide group, benzenesulfonamide group ), Sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylamino) Sulfonyl group, phenylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), urethane group (for example, methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, phenylureido group, 2-pyridylureido group, etc.), acyl Groups (eg, acetyl, propionyl, butanoyl, hexanoyl, cyclohexanoyl, benzoyl, pyridinoyl, etc.), carbamoyl groups (eg, aminocarbonyl, methylaminocarbonyl, dimethylaminocarbonyl, propylamino) Carbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, phenylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), acylamino group (for example, acetylamino group, benzoyla) Mino group, methylureido group etc.), sulfonyl group (eg methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, phenylsulfonyl group, 2-pyridylsulfonyl group etc.), amino group (eg amino group, Ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, anilino group, 2-pyridylamino group, etc.), halogen atom (eg chlorine atom, bromine atom, iodine atom etc.), cyano group, nitro group, sulfo group Carboxyl group, hydroxyl group, phosphono group (for example, phosphonoethyl group, phosphonopropyl group, phosphonooxyethyl group) and the like. Further, these groups may be further substituted with these groups.

Rl ₁ is preferably a substituted or unsubstituted phenyl group, more preferably a substituted or unsubstituted 2-hydroxyphenyl group or 4-hydroxyphenyl group.

The substituent represented by R1 ₂ or Rl ₃ is not particularly limited, and examples thereof include the substituents exemplified as the substituent on the aryl group of Rl ₁ . Rl ₂ and Rl ₃ are preferably an alkyl group, a cycloalkyl group, an aromatic group, or a heterocyclic group, which may have a substituent. Rl ₂ and Rl ₃ may be linked to each other to form a ring structure. The combination of Rl ₂ and Rl ₃ may be a phenyl group or a heterocyclic group, both of which may have a substituent, or Either one is a phenyl group or a heterocyclic group which may have a substituent, and the other is a combination of an alkyl group which may have a substituent.

X is preferably a> N-Rl _4. Rl ₄ is preferably a hydrogen atom, an alkyl group, an aromatic group, a heterocyclic group or an acyl group, more preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 5 to 10 carbon atoms, or acyl. It is a group.

  Among the azole dyes that are electrochromic compounds represented by the general formula (L), an imidazole dye represented by the following general formula (L2) is particularly preferable.

In the general formula (L2), Rl ₂₁ and Rl ₂₂ each represents an aliphatic group, an aliphatic oxy group, an acylamino group, a carbamoyl group, an acyl group, a sulfonamide group, or a sulfamoyl group, and R1 ₂₃ represents an aromatic group or an aromatic group. Rl ₂₄ represents a hydrogen atom, an aliphatic group, an aromatic group or an aromatic heterocyclic group, and Rl ₂₅ represents a hydrogen atom, an aliphatic group, an aromatic group or an acyl group.

These groups represented by Rl ₂₁ to Rl ₂₅ may be further substituted with an arbitrary substituent. However, at least one of the groups represented by Rl ₂₁ to Rl ₂₅ has —COOH, —P═O (OH) ₂ , —OP═O (OH) ₂ or —Si (OR) ₃ ( R represents an alkyl group.

In the general formula (L2), the group represented by Rl ₂₁ or Rl ₂₂ is preferably an alkyl group (particularly a branched alkyl group), a cycloalkyl group, an alkyloxy group, or a cycloalkyloxy group. Rl ₂₃ is preferably a substituted or unsubstituted phenyl group, a 5-membered or 6-membered heterocyclic group (for example, thienyl group, furyl group, pyrrolyl group, pyridyl group, etc.). Rl ₂₄ is preferably a substituted or unsubstituted phenyl group, a 5-membered or 6-membered heterocyclic group, or an alkyl group. Rl ₂₅ is particularly preferably a hydrogen atom or an aryl group.

  In the display element of the present invention, the compound represented by the general formula (L) or (L2) preferably has an adsorptive group that chemically or physically adsorbs on the electrode surface. The chemical adsorption referred to in the present invention is a relatively strong adsorption state due to a chemical bond with the electrode surface, and the physical adsorption referred to in the present invention is a relatively strong van der Waals force acting between the electrode surface and the adsorbed substance. It is weakly adsorbed.

In the present invention, the adsorptive group is preferably a chemisorbable group. Examples of the adsorptive group to be chemisorbed include —COOH, —P═O (OH) ₂ , —OP═O (OH) ₂ or -Si (OR) ₃ (R represents an alkyl group) is preferable.

In addition, when the compound represented by the general formula (L2) is fixed on the electrode, at least one of the groups represented by Rl _{21 to} Rl ₂₅ has a partial structure of —P═O (OH) ₂ or —Si. It is preferable to have (OR) ₃ (R represents an alkyl group), and in particular, —Si (OR) ₃ (R represents an alkyl group) as a partial structure of the group represented by Rl ₂₃ or Rl _24. It is preferable to have.

  Hereinafter, specific examples of the EC dye represented by the general formula (L2) and specific examples of the electrochromic dye included in the general formula (L), which do not correspond to the general formula (L2), are shown. The invention is not limited to these exemplified compounds.

  These electrochromic compounds are preferably immobilized on electrodes, particularly on the viewing side (display side). By fixing to the viewing side electrode, the viewing density can be improved.

[Metal species that dissolve and deposit electrically]
In the display element of the present invention, the electrochromic layer can contain a metal species that dissolves and precipitates electrochemically. Examples of such metal species include silver, bismuth, copper, nickel, iron, chromium, zinc, and the like, and silver and bismuth are preferable from the viewpoint that black display can be satisfactorily performed. To silver are preferred. These metal species are preferably added in the form of a metal salt compound, preferably a silver salt compound.

  Examples of the silver salt compound that can be preferably applied to the present invention include silver or a compound containing silver in the chemical structure, such as silver oxide, silver sulfide, metallic silver, silver colloidal particles, silver halide, silver complex compound, and silver ion. There are no particular restrictions on the state species of the phase such as the solid state, the solubilized state in liquid or the gaseous state, and the charged state species such as neutral, anionic, and cationic.

  In the display element of the present invention, silver iodide, silver chloride, silver bromide, silver oxide, silver sulfide, silver citrate, silver acetate, silver behenate, silver p-toluenesulfonate, silver trifluoromethanesulfonate, mercapto A known silver salt compound such as a silver salt with an acid or a silver complex with iminodiacetic acid can be used. Among these, it is preferable to use, as a silver salt, a compound that does not have a nitrogen atom having coordination properties with halogen, carboxylic acid, or silver, and for example, silver p-toluenesulfonate is preferable.

  The metal ion concentration contained in the electrolyte according to the present invention is preferably 0.2 mol / kg ≦ [Metal] ≦ 2.0 mol / kg. If the metal ion concentration is 0.2 mol / kg or more, a silver solution having a sufficient concentration can be obtained, and a desired driving speed can be obtained. If the metal ion concentration is 2 mol / kg or less, precipitation is prevented, and storage at low temperature is possible. The stability of the electrolyte solution is improved.

[Silver salt solvent]
In the display element of this invention, it is preferable that the electrochromic layer containing a metal seed | species contains the compound represented by the following general formula (G-1) or (G-2).

General formula (G-1)
_{Rg 11} -S-Rg ₁₂
In the general formula (G-1), Rg ₁₁ and Rg ₁₂ each represent a substituted or unsubstituted hydrocarbon group. Further, these hydrocarbon groups may contain one or more nitrogen atom, oxygen atom, phosphorus atom, sulfur atom or halogen atom, and Rg ₁₁ and Rg ₁₂ may be connected to each other to take a cyclic structure.

In the above general formula (G-2), M represents a hydrogen atom, a metal atom, or quaternary ammonium. Z represents an atomic group necessary for constituting a nitrogen-containing heterocyclic ring. n represents an integer of 0 to 5, and Rg ₂₁ represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkylcarbonamide group, an arylcarbonamide group, an alkylsulfonamide group, an arylsulfonamide group, an alkoxy group, an aryl Oxy group, alkylthio group, arylthio group, alkylcarbamoyl group, arylcarbamoyl group, carbamoyl group, alkylsulfamoyl group, arylsulfamoyl group, sulfamoyl group, cyano group, alkylsulfonyl group, arylsulfonyl group, alkoxycarbonyl group, Represents an aryloxycarbonyl group, an alkylcarbonyl group, an arylcarbonyl group, an acyloxy group, a carboxyl group, a carbonyl group, a sulfonyl group, an amino group, a hydroxy group or a heterocyclic group, and when n is 2 or more, Of Rg ₂₁ may be the same or different, and may be linked to each other to form a condensed ring.

  The thioether compound represented by the general formula (G-1) and the mercapto compound represented by the general formula (G-2), which can be preferably applied to the present invention, promote dissolution and precipitation of a metal species (particularly silver). It is a compound that functions as a silver salt solvent for this purpose.

  A silver salt solvent is a compound that can solubilize silver in an electrochromic layer, for example, a chemical structure that interacts with silver, such as a coordinate bond with silver and a weak supply bond with silver. In general, a method using a means for converting silver or a compound containing silver into a solubilizate in the presence of a compound containing a seed or the like is used. As the chemical structural species, a halogen atom, a mercapto group, a carboxyl group, an imino group, and the like are known. In the present invention, a compound containing a thioether group represented by the general formula (G-1) and a general formula ( The mercaptoazoles represented by G-2) are useful as a silver solvent, and have a feature that the influence on the coexisting compound is small and the solubility in the solvent is high.

In the general formula (G-1), Rg ₁₁ and Rg ₁₂ each represent a substituted or unsubstituted hydrocarbon group, and in these hydrocarbon groups, one or more nitrogen atoms, oxygen atoms, phosphorus atoms, sulfur An atom may be included, and Rg ₁₁ and Rg ₁₂ may be connected to each other to take a cyclic structure.

  Examples of groups that can be substituted for the hydrocarbon group include amino groups, guanidino groups, quaternary ammonium groups, hydroxyl groups, halogen compounds, carboxylic acid groups, carboxylate groups, amide groups, sulfinic acid groups, sulfonic acid groups, and sulfates. Groups, phosphonic acid groups, phosphate groups, nitro groups, cyano groups and the like.

  Specific examples of the compound represented by General Formula (G-1) that can be applied in the present invention are shown below, but the present invention is not limited to these exemplified compounds.

G1-1: CH ₃ SCH ₂ CH ₂ OH
G1-2: HOCH ₂ CH ₂ SCH ₂ CH ₂ OH
G1-3: HOCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OH
G1-4: HOCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OH
G1-5: HOCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ OH
_{G1-6: HOCH 2 CH 2 OCH 2} CH 2 SCH 2 CH 2 SCH 2 CH 2 OCH 2 CH 2 OH
G1-7: H ₃ CSCH ₂ CH ₂ COOH
G1-8: HOOCCH ₂ SCH ₂ COOH
G1-9: HOOCCH ₂ CH ₂ SCH ₂ CH ₂ COOH
G1-10: HOOCCH ₂ SCH ₂ CH ₂ SCH ₂ COOH
G1-11: HOOCCH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ COOH
G1-12: HOOCCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH (OH) CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ COOH
G1-13: HOOCCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH (OH) CH (OH) CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ COOH
G1-14: H ₃ CSCH ₂ CH ₂ CH ₂ NH ₂
G1-15: H ₂ NCH ₂ CH ₂ SCH ₂ CH ₂ NH ₂
G1-16: H ₂ NCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NH ₂
G1-17: H ₃ CSCH ₂ CH ₂ CH (NH ₂ ) COOH
G1-18: H ₂ NCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ NH _{2
G1-19: H 2 NCH 2 CH 2} SCH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 SCH 2 CH 2 NH 2
G1-20: H ₂ NCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NH ₂
G1-21: HOOC (NH ₂ ) CHCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ CH (NH ₂ ) COOH
G1-22: HOOC (NH ₂ ) CHCH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH (NH ₂ ) COOH
G1-23: HOOC (NH ₂ ) CHCH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH (NH ₂ ) COOH
_{G1-24: H 2 N (O =} ) CCH 2 SCH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 SCH 2 C (= O) NH 2
_{G1-25: H 2 N (O =} ) CCH 2 SCH 2 CH 2 SCH 2 C (= O) NH 2
_{G1-26: H 2 NHN (O =} ) CCH 2 SCH 2 CH 2 SCH 2 C (= O) NHNH 2
_{G1-27: H 3 C (O =} ) CNHCH 2 CH 2 SCH 2 CH 2 SCH 2 CH 2 NHC (= O) CH 3
_{G1-28: H 2 NO 2 SCH 2} CH 2 SCH 2 CH 2 SCH 2 CH 2 SO 2 NH 2
_{G1-29: NaO 3 SCH 2 CH 2} CH 2 SCH 2 CH 2 SCH 2 CH 2 CH 2 SO 3 Na
G1-30: H ₃ CSO ₂ NHCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NHO ₂ SCH ₃
G1-31: H ₂ N (NH═) CSCH ₂ CH ₂ SC (═NH) NH ₂ .2HBr
_{G1-32: H 2 N (NH =} ) CSCH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 SC (= NH) NH 2 · 2HCl
_{G1-33: H 2 N (NH =} ) CNHCH 2 CH 2 SCH 2 CH 2 SCH 2 CH 2 NHC (= NH) NH 2 · 2HBr
G1-34: [(CH ₃ ) ₃ NCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ N (CH ₃ ) ₃ ] 2 ⁺ · 2Cl ⁻

  Of the above-exemplified compounds, Exemplified Compounds G1-2 and G1-3 are particularly preferable from the viewpoint that the object and effects of the present invention can be exhibited.

  Next, the compound represented by formula (G-2) according to the present invention will be described.

In the general formula (G-2), examples of the metal atom represented by M include Li, Na, K, Mg, Ca, Zn, and Ag. Examples of the quaternary ammonium include NH _4. , N (CH ₃ ) ₄ , N (C ₄ H ₉ ) ₄ , N (CH ₃ ) ₃ C ₁₂ H ₂₅ , N (CH ₃ ) ₃ C ₁₆ H ₃₃ , N (CH ₃ ) ₃ CH ₂ C ₆ H ₅ etc. are mentioned.

  Examples of the nitrogen-containing heterocycle having Z as a constituent component include a tetrazole ring, a triazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, an indole ring, an oxazole ring, a benzoxazole ring, a benzimidazole ring, a benzothiazole ring, Examples thereof include a benzoselenazole ring and a naphthoxazole ring.

Specific examples of the group represented by Rg ₂₁ include a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and an alkyl group such as methyl, ethyl, propyl, i-propyl, Examples of aryl groups such as butyl, t-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, octyl, dodecyl, hydroxyethyl, methoxyethyl, trifluoromethyl, benzyl, etc., for example, phenyl, naphthyl, etc. For example, acetylamino, propionylamino, butyroylamino, etc., as arylcarbonamido group, for example, benzoylamino, etc., alkylsulfonamido group, for example, methanesulfonylamino group, ethanesulfonylamino group, etc., arylsulfonamido, etc. As a dodo group, for example, a benzenesulfonylamino group, a toluenesulfonylamino group, etc., an aryloxy group, for example, phenoxy, etc., an alkylthio group, for example, methylthio, ethylthio, butylthio, etc., an arylthio group, for example, Examples of alkylcarbamoyl groups such as phenylthio group and tolylthio group include methylcarbamoyl, dimethylcarbamoyl, ethylcarbamoyl, diethylcarbamoyl, dibutylcarbamoyl, piperidylcarbamoyl, morpholylcarbamoyl, and arylcarbamoyl groups such as phenylcarbamoyl, methyl Examples of alkylsulfamoyl groups such as phenylcarbamoyl, ethylphenylcarbamoyl, benzylphenylcarbamoyl and the like include, for example, methylsulfamoyl As arylsulfamoyl groups, for example, phenylsulfamoyl, methyl, dimethylsulfamoyl, ethylsulfamoyl, diethylsulfamoyl, dibutylsulfamoyl, piperidylsulfamoyl, morpholylsulfamoyl, etc. Examples of the alkylsulfonyl group such as phenylsulfamoyl, ethylphenylsulfamoyl, benzylphenylsulfamoyl, etc. include, for example, methanesulfonyl group, ethanesulfonyl group, etc. Examples of the arylsulfonyl group include phenylsulfonyl, 4-chlorophenylsulfonyl And alkoxycarbonyl groups such as methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl and the like, and aryloxycarbonyl groups such as phenoxy Bonyl and the like, as the alkylcarbonyl group, for example, acetyl, propionyl, butyroyl, etc., as the arylcarbonyl group, for example, benzoyl group, alkylbenzoyl group, etc., as the acyloxy group, for example, acetyloxy, propionyloxy, butyroyloxy, etc. Examples of the heterocyclic group include oxazole ring, thiazole ring, triazole ring, selenazole ring, tetrazole ring, oxadiazole ring, thiadiazole ring, thiazine ring, triazine ring, benzoxazole ring, benzthiazole ring, indolenine ring, benz Examples include a selenazole ring, a naphthothiazole ring, a triazaindolizine ring, a diazaindolizine ring, and a tetraazaindolizine ring group. These substituents further include those having a substituent.

  Next, although the preferable specific example of a compound represented by general formula (G-2) is shown, this invention is not limited to these compounds.

  Among the above-exemplified compounds, Exemplified Compounds G2-12, G2-13, G2-18, and G2-20 are particularly preferable from the viewpoint that the objective effect of the present invention can be suitably exhibited.

〔solvent〕
When the electrochromic layer according to the present invention is in a liquid phase, a solvent that dissolves the electrochromic compound is used. As such a solvent, a solvent that is generally used in electrochemical cells and batteries and that can dissolve various additives such as metal salt compounds and promoters that are reversibly dissolved and precipitated by an electrochemical oxidation-reduction reaction can be used. .

  Specifically, acetic anhydride, methanol, ethanol, tetrahydrofuran, ethylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, butylene carbonate, propylene carbonate, nitromethane, acetonitrile, acetylacetone, N-methylformamide, N, N-dimethylformamide , Dimethyl sulfoxide, hexamethylphosphoamide, dimethoxyethane, diethoxyfuran, γ-butyrolactone, γ-valerolactone, sulfolane, propionitrile, butyronitrile, glutaronitrile, adiponitrile, methoxyacetonitrile, N-methylacetamide, N, N -Dimethylacetamide, N-methylpropionamide, methylpyrrolidinone, 2- (N-methyl) -2-pyrrolidi Non, dimethyl sulfoxide, dioxolane, trimethyl phosphate, triethyl phosphate, tripropyl phosphate, ethyl dimethyl phosphate, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, tris ( Trifluoromethyl) phosphate, tris (pentafluoroethyl) phosphate, triphenyl phosphate, tricresyl phosphate, 2-ethylhexyl phosphate, tetramethylurea, 1,3-dimethyl-2-imidazolidinone, hexamethylphosphotriamide, 4-methyl-2-pentanone, dioctyl phthalate, dioctyl sebacate, and ethylene glycol Lumpur, diethylene glycol, polyethylene glycols such as triethylene glycol monobutyl ether and the like can be used.

  Furthermore, room temperature molten salts can also be used as solvents. The room temperature molten salt is a salt composed of ion pairs that are melted at room temperature (that is, in a liquid state) consisting only of ion pairs that do not contain a solvent component, and usually has a melting point of 20 ° C. or lower, A salt consisting of an ion pair that is liquid at a temperature above. The room temperature molten salt can be used alone or in combination of two or more.

  The solvent used in the present invention is preferably an aprotic polar solvent, particularly propylene carbonate, ethylene carbonate, dimethyl sulfoxide, dimethoxyethane, acetonitrile, γ-butyrolactone, sulfolane, dioxolane, dimethylformamide, dimethoxyethane, tetrahydrofuran, adiponitrile, methoxy. Acetonitrile, dimethylacetamide, methyl pyrrolidinone, dimethyl sulfoxide, dioxolane, sulfolane, trimethyl phosphate and triethyl phosphate are preferred. The solvent may be used alone or in combination of two or more.

〔Electrolytes〕
The electrochromic layer according to the present invention can contain an electrolyte.

  The “electrolyte” as used in the present invention generally refers to a substance that dissolves in a solvent such as water and exhibits a ionic conductivity in a solution (hereinafter referred to as “narrowly defined electrolyte”). A mixture containing other metals, compounds, or the like, regardless of whether it is an electrolyte or a non-electrolyte, is called an electrolyte (“broadly defined electrolyte”).

(Supporting electrolyte)
As the supporting electrolyte that can be used in the display element of the present invention, salts, acids, and alkalis that are usually used in the field of electrochemistry or the field of batteries can be used.

  There are no particular limitations on the salts, and for example, inorganic ion salts such as alkali metal salts and alkaline earth metal salts; quaternary ammonium salts; cyclic quaternary ammonium salts; quaternary phosphonium salts and the like can be used.

  The amount of the supporting electrolyte used is arbitrary, but generally the upper limit is 20 mol / L or less, preferably 10 mol / L or less, more preferably 5 mol / L or less in the solvent. Desirably, the lower limit is usually 0.01 mol / L or more, preferably 0.05 mol / L or more, more preferably 0.1 mol / L or more.

(Gel-like electrochromic layer)
In the display element of this invention, it can be made thick by using a thickener for the medium which forms an electrochromic layer, and can be made into a gel form.

  Examples of such thickeners include gelatin, gum arabic, poly (vinyl alcohol), hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose acetate, cellulose acetate butyrate, poly (vinyl pyrrolidone), poly (alkylene glycol), and casein. , Starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid), copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene) , Poly (vinyl acetals) (for example, poly (vinyl formal) and poly (vinyl butyral)), poly (esters), poly (urethane) s, phenoxy resins, poly (vinylidene chloride), poly (epoxides), Poly Carbonates), poly (vinyl acetate), cellulose esters, poly (amides), and hydrophobic transparent binders such as polyvinyl butyral, cellulose acetate, cellulose acetate butyrate, polyester, polycarbonate, polyacrylic acid, and polyurethane. .

  These thickeners may be used in combination of two or more. Moreover, the compound as described in pages 71-75 of Unexamined-Japanese-Patent No. 64-13546 can be mentioned. Among these, the compounds preferably used are polyvinyl alcohols, polyvinyl pyrrolidones, hydroxypropyl celluloses, and polyalkylene glycols from the viewpoint of compatibility with various additives and improvement in dispersion stability of white particles.

  Further, for example, solid electrolytes described in JP-A No. 2002-341387, polymer solid electrolytes described in JP-A No. 2002-341387, polymer solid electrolytes described in JP-A No. 2004-20928, and JP-A No. 2004-2004 Polymer solid electrolyte described in Japanese Patent No. 191945, solid polymer electrolyte described in Japanese Patent Application Laid-Open No. 2005-338204, polymer solid electrolyte described in Japanese Patent Application Laid-Open No. 2006-323022, and Japanese Patent Application Laid-Open No. 2007-141658. Solid electrolytes described in JP-A-2007-163865, gel electrolytes, and the like.

[Nanoporous layer]
The display element of the present invention preferably has a nanoporous layer. The nanoporous layer is a layer having a large number of nano-sized pores in the layer. The nanoporous layer according to the present invention is contained in the electrochromic layer constituting the electrochromic display unit. For the purposes of the present invention, it is desirable that the nanoporous layer be substantially transparent within the electrochromic layer. Examples of the material for forming such a nanoporous layer include glass, polymethyl methacrylate (PMMA), tin oxide, zinc oxide, zirconium, silica, and the like. Can be used.

  The nanoporous layer can be formed by stacking and binding fine particles of the above materials. Similarly to the method for forming the white scattering layer, the fine particles are dispersed in a binder resin, and the fine particles are applied to a predetermined thickness and dried to form a layer. It is also possible to incinerate the binder resin to bind the fine particles. As another method, a method called a liquid phase precipitation method can also be used. In the case of zinc oxide or the like, it can be made porous by an anodic oxidation method.

  Since the nanoporous layer according to the present invention is contained in the electrochromic layer, the electrochromic compound can be immobilized in the nanoporous structure. The configuration of the present invention can also be achieved by bringing the electrochromic compound into advance and then bringing it into contact with other components that form the electrochromic layer.

  By immobilizing the electrochromic compound on the nanoporous layer, the amount of the electrochromic compound that can be contained in the electrochromic layer can be increased. In addition, the reactivity of the electrochromic compound is unlikely to deteriorate. Furthermore, since there is no diffusion of the colored electrochromic compound, a stable high-density image can be obtained.

[Immobilization of electrochromic compounds]
The method of immobilizing the electrochromic compound on the nanoporous layer is preferably a method of introducing a group that chemically or physically adsorbs to the surface of the nanoporous layer into the electrochromic compound.

  The chemical adsorption according to the present invention is a relatively strong adsorption state due to a chemical bond with the electrode surface, and the physical adsorption according to the present invention is a relatively strong van der Waals force acting between the electrode surface and the adsorbed substance. It is weakly adsorbed.

The immobilization according to the present invention is preferably performed by chemical adsorption, and the adsorptive groups to be chemically adsorbed include —COOH, —P═O (OH) ₂ , —OP═O (OH) ₂ and —Si (OR) ₃ ( R represents an alkyl group).

[Other additives]
The electrochromic layer according to the present invention can contain a complexing agent, a redox reaction accelerator, a redox buffer, and the like. The oxidation-reduction reaction accelerator is a compound that has an effect of increasing the reactivity by reacting with a smaller amount of electricity than the electrochromic compound and passing this charge to the electrochromic compound. The redox buffer is a compound having an effect of maintaining the transparent state of the electrochromic layer as described in, for example, JP-T-2007-508587.

[Sealant]
The peripheral portion of the display element of the present invention is required to be sealed with a sealant. The sealing agent has an effect of sealing so that the electrochromic layer does not leak outside, and an effect of preventing moisture and gas from entering the system from the outside. Also known as sealant, such as epoxy resin, urethane resin, acrylic resin, vinyl acetate resin, ene-thiol resin, silicon resin, modified polymer resin, etc. A curing type such as an anaerobic curing type can be used.

[Other component layers]
Examples of the constituent layers of the display element of the present invention include auxiliary layers such as a protective layer, a filter layer, an antihalation layer, a crossover light cut layer, and a backing layer. Sensitizer, noble metal sensitizer, photosensitive dye, supersensitizer, coupler, high boiling point solvent, antifoggant, stabilizer, development inhibitor, bleach accelerator, fixing accelerator, color mixing inhibitor, formalin scavenger, Toning agents, hardeners, surfactants, thickeners, plasticizers, slip agents, UV absorbers, anti-irradiation dyes, filter light absorbing dyes, anti-bacterial agents, polymer latex, heavy metals, antistatic agents, matting agents Etc. can be contained as required.

  These additives mentioned above are more specifically described in Research Disclosure (hereinafter abbreviated as RD), Volume 176 Item / 17643 (December 1978), Volume 184, Item / 18431 (August 1979), 187. Volume Item / 18716 (November 1979) and Volume 308 Item / 308119 (December 1989).

  Table 1 below shows the types of compounds and the locations described in these three research disclosures.

〔Indicated Area〕
In the display element of the present invention, since a region sandwiched between pixel electrodes on the same plane is colored, when a plurality of pixels are combined, as shown in FIG. Resulting in. If this non-colored region is too wide, the overall display density is lowered as a result. For this reason, it is preferable that the area of the colored region is 70% or more of the total display region area.

[Pixel thickness and width]
The relationship between the thickness T of the electrochromic layer and the electrode pixel interval L is shown in FIG. If T is made thick, the electrochromic compound that can be contained in the display element can be increased. If L is widened, a sufficient colored region can be obtained in design. However, it has been found that if T is too thick or L is too long, the color density cannot be obtained sufficiently high, or the driving becomes difficult in some cases.

  In the display element of the present invention, the relationship L / T between the thickness T (μm) of the electrochromic layer and the corresponding distance L (μm) between the pair of electrodes is 2.5 ≦ L / T ≦ 10. It is preferable.

[Product application]
The display element of the present invention can be used in an electronic book field, an office-related field, an ID card-related field, a public-related field, a transportation-related field, a broadcasting-related field, a settlement-related field, a distribution-related field, and the like. Specifically, door keys, student ID cards, employee ID cards, various membership cards, point cards, subway and railway IC cards, bus cards, cash cards, credit cards, highway cards, driver's licenses, hospital examinations Cards, electronic medical records, health insurance cards, Basic Resident Registers, passports, document readers, electronic books, various notice boards, advertisement displays, etc.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

<< Production of substrate with electrodes >>
[Production of substrate 1 with electrode]
The ITO film on the glass substrate with an ITO film (thickness 0.7 mm) was etched by a known method to form a stripe pixel electrode having a width of 130 μm and an interval of 20 μm, and the substrate 1 with an electrode was produced.

[Production of substrate 2 with electrode]
A silver-palladium electrode having a pixel electrode arrangement pattern shown in FIG. 6 was formed on a 0.7 mm thick glass substrate by sputtering to produce a substrate 2 with electrodes. The distance between the pixel electrode pairs was 120 μm, the distance between adjacent pixel electrodes was 20 μm, the size of each electrode was 5 μm wide, 130 μm long, and 2 μm thick. The area of the colored region is about 69% of the total pixel area.

[Production of substrate 3 with electrode]
A silver-palladium electrode having a pixel electrode arrangement pattern shown in FIG. 7 was formed on a 0.7 mm thick glass substrate by sputtering to produce a substrate 3 with electrodes. The distance between the pixel electrode pairs was 130 μm, the distance between adjacent pixel electrode cities was 10 μm, the size of each electrode was 5 μm wide, 140 μm long, and 2 μm thick. The area of the colored region is about 81% of the total pixel area.

[Preparation of substrate 4 with electrodes]
In the production of the substrate 2 with electrodes, as shown in FIG. 4, after applying a mixed liquid of methyl methacrylate and a curing agent between adjacent pixel electrode pairs and curing by exposure to ultraviolet rays through masking, A substrate 4 with an electrode was produced in the same manner except that the uncured portion was removed and a bank having a width of 10 μm, a length of 130 μm, and a height of 5 μm was formed. The area of the colored region is about 69% of the total pixel area.

[Preparation of substrate 5 with electrode]
A silver-palladium electrode having a pixel electrode arrangement pattern shown in FIG. 6 was formed on a glass substrate having a thickness of 0.7 mm by sputtering. The distance between the pixel electrode pairs was 130 μm, the distance between adjacent pixel electrodes was 10 μm, the size of each electrode was 5 μm wide, 140 μm long, and 2 μm thick. A liquid mixture of methyl methacrylate and a curing agent is applied thereon, and cured by exposure to ultraviolet rays through masking. Then, an uncured portion is removed, and a width of 5 μm, a length of 140 μm, and a height between adjacent pixel electrodes are removed. A bank having a thickness of 5 μm was formed to form a substrate 5 with electrodes. The area of the colored region is about 83% of the total pixel area.

<< Preparation of white scattering layer forming liquid >>
In an isopropanol solution containing 2% by mass of polyvinyl alcohol (average polymerization degree 3500, saponification degree 87%), 20% by mass of titanium oxide was dispersed with an ultrasonic disperser to prepare a liquid for forming a white scattering layer.

<< Preparation of electrochromic layer forming liquid >>
[Preparation of Electrochromic Layer Forming Solution A]
0.2 mol of tetrabutylammonium perchlorate in propylene carbonate, 2- {2- [4- (dimethylamino) phenyl] ethenyl} -3,3-dimethyl-5-phosphonoindolino [2,1-b ] 0.4 mol of oxazoline (yellow color electrochromic compound) was dissolved, and 20 parts by mass of polyvinyl butyral (Sekisui Chemical Co., Ltd., ESREC BH3) was added thereto to give a yellow color developing electrochromic layer forming solution A. Was prepared.

[Preparation of Electrochromic Layer Forming Solution B]
In preparation of the electrochromic layer forming liquid A, instead of 2- {2- [4- (dimethylamino) phenyl] ethenyl} -3,3-dimethyl-5-phosphonoindolino [2,1-b] oxazoline 2- {2- [4- (dimethylamino) phenyl] -1,3-butadienyl} -3,3-dimethyl-5-carboxylindolino [2,1-b] oxazoline (magenta colored electrochromic compound) ) Was used in the same manner to prepare a magenta electrochromic layer forming solution B.

[Preparation of Electrochromic Layer Forming Solution C]
In preparation of the electrochromic layer forming liquid A, instead of 2- {2- [4- (dimethylamino) phenyl] ethenyl} -3,3-dimethyl-5-phosphonoindolino [2,1-b] oxazoline 2- {2- [4- (methoxy) phenyl] -1,3,5-hexatrienyl} -3,3-dimethyl-5-phosphonoindolino [2,1-b] A cyan color-forming electrochromic layer forming solution C was prepared in the same manner except that the electrochromic compound) was used.

[Preparation of Electrochromic Layer Forming Solution D]
In the preparation of the electrochromic layer forming liquid C, an electrochromic layer forming liquid D was prepared in the same manner except that 20 parts by mass of titanium oxide having an average particle size of 23 nm was further added and dispersed using an ultrasonic dispersing machine. .

[Preparation of Electrochromic Layer Forming Solution E]
In γ-butyrolactone, 0.05 mol / L lithium perchlorate and 0.05 mol / L ferrocene are dissolved, and as an electrochromic compound, exemplary compound (L69) is 0.2 mol / L, polyvinyl butyral (Sekisui 20 parts by mass of ESREC BH3) manufactured by Chemical Industry Co., Ltd. was added to prepare a yellow color-forming electrochromic layer forming liquid E.

[Preparation of Electrochromic Layer Forming Solution F]
In γ-butyrolactone, 0.05 mol / L lithium perchlorate and 0.05 mol / L ferrocene are dissolved, and the exemplary compound (L69) is 0.2 mol / L as an electrochromic compound. 0.3 parts by weight of silver oxide, 0.04 parts by weight of the following compound A-1 and 20 parts by weight of polyvinyl butyral (Sleek BH3 manufactured by Sekisui Chemical Co., Ltd.) are added to form an electrochromic layer with yellow and black color development. Liquid F was prepared.

[Preparation of Electrochromic Layer Forming Solution G]
In γ-butyrolactone, 0.05 mol / L lithium perchlorate and 0.05 mol / L ferrocene are dissolved, and as an electrochromic compound, exemplary compound (L70) is 0.2 mol / L, polyvinyl butyral (Sekisui Magenta electrochromic layer-forming solution G was prepared by adding 20 parts by mass of Chemical Industries Ltd. S-REC BH3).

[Preparation of Electrochromic Layer Forming Solution H]
In γ-butyrolactone, 0.05 mol / L of lithium perchlorate and 0.05 mol / L of ferrocene are dissolved, and the exemplary compound (L71) is 0.2 mol / L as an electrochromic compound, polyvinyl butyral (Sekisui 20 parts by mass of ESREC BH3) manufactured by Kagaku Kogyo Co., Ltd. was added to prepare a cyan color-forming electrochromic layer forming liquid H.

[Preparation of Electrochromic Layer Formation Liquid I]
In γ-butyrolactone, 0.05 mol / L of lithium perchlorate and 0.05 mol / L of ferrocene are dissolved, and the exemplary compound (L71) is 0.2 mol / L as an electrochromic compound, polyvinyl butyral (Sekisui 20 parts by mass of S-Rec BH3) manufactured by Chemical Industry Co., Ltd., 30 parts by mass of titanium oxide (primary average particle size: 0.34 μm) are added, dispersed with an ultrasonic disperser, and a cyan coloring electrochromic layer Forming liquid I was prepared.

[Preparation of Electrochromic Layer Formation Liquid J]
In the preparation of the electrochromic layer forming solution F, electrochromic layer formation was performed in the same manner except that 0.4 parts by mass of the exemplified compound G2-20, which is a compound represented by the general formula (G-2), was further added. Liquid J was prepared.

<< Preparation of electrolyte >>
[Preparation of Electrolytic Solution 1]
In propylene carbonate, 0.2 mol of tetrabutylammonium perchlorate was dissolved, and 20 parts by mass of polyvinyl butyral (Sekisui Chemical Co., Ltd., ESREC BH3) was added and dissolved therein to obtain an electrolytic solution 1.

[Preparation of Electrolyte 2]
5 parts by mass of N-methylpyrrolidone, 0.26 parts by mass of triphenylphosphine, 0.08 parts by mass of (nC ₄ H ₉ ) ₄ NClO ₄ , 0.3 parts by mass of silver p-toluenesulfonate, compound 0.01 part by mass of A-1 (supra), 0.4 part by mass of exemplary compound G2-13 represented by the general formula (G-2), polyvinyl butyral (Surek Chemical Co., Ltd., ESREC BH3) 20 parts by mass was added and dissolved to obtain an electrolytic solution 2.

<< Formation of nanoporous layer >>
[Formation of nanoporous layer (1)]
To 1.5 ml of a 15% by mass SnO ₂ colloidal aqueous solution (SnO ₂ : average particle size: 15 nm), 0.3 ml of acetic acid was dropped and mixed well in a mortar to a ZnO powder (average particle size: 0 0.2 μm) and 20 ml of methanol were added little by little and mixed well. This mixture was applied several times on glass placed on a hot plate (100 to 120 ° C.) while being dried, and finally baked at 550 ° C. to form a nanoporous layer (1) of ZnO / SnO ₂ mixture. . The thickness of the nanoporous layer (1) was 5 μm.

[Formation of nanoporous layer (2)]
Zinc oxide was formed to have a thickness of about 5 μm, and a zinc oxide nanoporous layer (2) was obtained by a known anodic oxidation method.

<< Production of display element >>
[Production of Display Element 1]
Electrochromic layer forming liquid A, electrochromic layer forming liquid B, and electrochromic layer forming liquid D were applied to the surface of the three substrates 1 with electrode layers having the electrode layers so as to have a thickness of 50 μm, respectively. Display unit A1, electrochromic display unit B1, and electrochromic display unit D1 were produced.

  Next, the substrate 1 of the electrochromic display unit B1 was bonded onto the electrochromic layer D of the electrochromic display unit D1, and the substrate 1 of the electrochromic display unit A1 was bonded onto the electrochromic layer B.

  Next, glass with ITO (thickness 0.7 mm) is stacked on the electrochromic layer A of the electrochromic display unit A1 so that the ITO surface is in contact with the electrochromic layer A, and the periphery is sealed with an epoxy sealant. A display element 1 was produced.

[Production of Display Element 2]
An electrochromic layer forming solution A, an electrochromic layer forming solution B, and an electrochromic layer forming solution D are applied on the surface having the electrodes of the three substrates 2 with an electrode layer so as to have a thickness of 50 μm, respectively. Unit A2, electrochromic display unit B2, and electrochromic display unit D2 were produced.

  Next, the substrate 2 of the electrochromic display unit B2 was bonded onto the electrochromic layer D of the electrochromic display unit D2, and the substrate 2 of the electrochromic display unit A2 was bonded onto the electrochromic layer B.

  Next, 0.7 mm thick glass is stacked on the electrochromic layer A, the periphery is sealed with an epoxy sealant, and a white acrylic plate is stacked on the outer surface of the substrate of the electrochromic display unit D2, thereby producing a display element 2. did.

[Production of Display Element 3]
A liquid for forming a white scattering layer was applied on the surface of the substrate 2 with an electrode layer, and then dried at 15 ° C. for 30 minutes, followed by baking at 120 ° C. for 1 hour to obtain a white scattering layer. The dry thickness of the white scattering layer was about 20 μm.

  An electrochromic layer C was applied on the above-prepared electrode and the substrate 2 having white scattering, so that the total thickness was about 50 μm to obtain an electrochromic display unit C3.

  Next, the electrochromic display unit C3 and the electrochromic display unit B2 and electrochromic display unit A2 used in the manufacture of the display element 2 are stacked and bonded in the same manner as the display element 2, and a 0.7 mm thick glass is formed. The display element 3 was manufactured by overlapping and sealing the periphery with an epoxy sealant.

[Production of Display Element 4]
Electrochromic layer forming liquid A, electrochromic layer forming liquid B, and electrochromic layer forming liquid D are respectively applied on the surface having the electrodes of the substrate 4 with three electrode layers so as to have a thickness of 50 μm. Unit A4, electrochromic display unit B4, and electrochromic display unit D4 were obtained.

  Next, the substrate 4 of the electrochromic display unit B4 was bonded onto the electrochromic layer D of the electrochromic display unit D4, and the substrate 4 of the electrochromic display unit A4 was bonded onto the electrochromic layer B.

  Subsequently, 0.7 mm thick glass was laminated on the electrochromic layer A, and the periphery was sealed with an epoxy-based sealant to produce a display element 4.

[Preparation of display element 5]
A white scattering layer is formed on the surface having the electrodes of the substrate 4 with the electrode layer in the same manner as the display element 3 so as to have a dry film thickness of about 20 μm, and an electrochromic layer forming liquid C is applied to the entire surface. An electrochromic display unit C5 was produced with a thickness of 50 μm. Using this electrochromic display unit C5, and the electrochromic display unit A4 and electrochromic display unit B4 used in the production of the display element 4, a display element 5 was produced in the same manner as in the production of the display element 4.

[Production of Display Element 6]
In the production of the display element 5, the display element 6 was produced in the same manner except that the nanoporous layer (1) was formed on the top of each electrochromic layer.

[Production of display element 7]
In the production of the display element 6, a display element 7 was produced in the same manner except that the nanoporous layer (2) was used instead of the nanoporous layer (1).

[Production of Display Element 8]
In the production of the display element 6, in place of the electrochromic layer forming liquid A, the electrochromic layer forming liquid E is replaced with the electrochromic layer forming liquid B, and the electrochromic layer forming liquid G is replaced with the electrochromic layer forming liquid C. Instead of using the electrochromic layer forming liquid H, a display element 8 was produced in the same manner.

[Production of Display Element 9]
In the production of the display element 6, a display element 9 was produced in the same manner except that the electrochromic layer forming liquid F was used instead of the electrochromic layer forming liquid E.

[Production of Display Element 10]
A display element 10 was produced in the same manner as in the production of the display element 9 except that the substrate 4 with an electrode layer was replaced with the substrate 3 with an electrode layer.

[Production of Display Element 11]
A display element 11 was produced in the same manner as in the production of the display element 10 except that the thickness of each electrochromic layer was changed to 35 μm.

[Production of Display Element 12]
A display element 12 was produced in the same manner as in the production of the display element 11 except that the substrate 3 with electrode layer was changed to the substrate 2 with electrode.

[Production of Display Element 13]
The electrochromic layer forming liquid J was applied to the electrode-side surface of the substrate 5 so as to have a thickness of 35 μm, and the nanoporous layer (1) was immersed therein to obtain an electrochromic display unit J13. Similarly, electrochromic display units G13 and H13 were obtained using the electrochromic layer forming solution G and the electrochromic forming solution H. These were laminated in the same configuration as the display element 11 to produce a display element 13.

[Production of Display Element 14]
A white scattering layer was formed to a thickness of 15 μm on the electrode side surface of the substrate 5 in the same manner as the display element 3. On top of this, the electrochromic layer forming liquid J was applied so that the total thickness was 35 μm, and the nanoporous layer (1) was immersed therein to obtain an electrochromic display unit J14. Also, the electrochromic layer forming solution G and the electrochromic layer forming solution H are applied to the surface of the substrate 5 on the electrode side so as to have a thickness of 35 μm, respectively, and the nanoporous layer (1) is immersed therein, and the electrochromic display unit G14 and H14 were obtained. Next, using the electrochromic display units J14, G14, and H14, the display element 14 was obtained by laminating with the same configuration as the display element 11.

[Production of Display Element 15]
An ethanol solution of the exemplified compound (L17) was prepared as an electrochromic compound, and the nanoporous layer (1) was immersed in this solution for 12 hours, then taken out, and the ethanol was dried to adsorb the electrochromic compound (L17). A quality layer (1) A was obtained.

  Next, the nanoporous layer (1) is dipped in the same manner for the exemplary compound (L18) and the exemplary compound (L19) as the electrochromic compound, and the nanoporous layer (1) B and nanoporous layer (1) C are immersed. Got.

  Next, the white porous layer is formed on the substrate 5 with the electrode layer so as to have a thickness of 15 μm, and the nanoporous layer (1) C is overlaid on the electrolyte solution 1 applied so as to have a thickness of about 20 μm. To obtain an electrochromic display unit C15.

  Next, the nanoporous layer (1) B was overlaid on the substrate 5 with an electrode layer coated with the electrolytic solution 1 so as to have a thickness of about 20 μm, and dipped to obtain an electrochromic display unit B15.

  Next, the electrolyte solution 2 was applied on the substrate 5 with an electrode layer so as to have a thickness of about 20 μm, and the nanoporous layer (1) A was overlaid and immersed therein to obtain an electrochromic display unit A15.

  Next, the produced electrochromic display units C15, B15, and A15 were stacked, and a glass having a thickness of 0.7 mm was stacked on the uppermost portion, and the periphery was sealed with an epoxy resin, whereby a display element 15 was manufactured.

<< Evaluation of display element >>
Each of the produced display elements was evaluated as follows.

[Evaluation of white reflectance characteristics]
The total wavelength average reflectance of each display element in an uncolored state, that is, a white display state was measured using a spectrocolorimeter CM-3700d manufactured by Konica Minolta Sensing Co., Ltd., and white reflectance characteristics were evaluated according to the following criteria. .

×: Average reflectance is less than 50% Δ: Average reflectance is 50% or more and less than 55% ○: Average reflectance is 55% or more and less than 60% ◎: Average reflectance is 60% or more [Evaluation of repeated durability]
An extraction electrode from the electrode of each display element was connected to a drive circuit through a contact hole. Next, for each display element, each constituting electrochromic layer is driven independently at a driving voltage of 1.5 V, and the driving time during which the contrast with the white reflectance at the absorption peak wavelength of each electrochromic layer is 5.0. Asked. That is, in the case of displaying each color, the initial contrast is set to 5.0. For black display due to metal deposition, the initial contrast was obtained from the reflectance at a wavelength of 550 nm.

  With this driving time, each electrochromic layer is driven 1000 times independently, the contrast after 1000 times driving is measured, the contrast fluctuation rate (contrast after 1000 times driving / initial contrast) is obtained, and this is repeated for durability. It was used as an index.

  The results obtained as described above are shown in Table 2.

  As is clear from the results shown in Table 2, for a display element having an electrochromic display unit having a configuration defined in the present invention, formation of a white scattering layer, introduction of a bank, introduction of a nanoporous layer, or It was confirmed that the durability was improved by expanding the total display area. Moreover, durability was remarkably improved by using the compound represented by general formula (L2) as an electrochromic compound. The black display due to the metal deposition was clearer than the black due to the mixed color of yellow, magenta and cyan, and a high density was obtained.

  The display elements 10, 11, 13, 14, and 15 with the ratio of the colored region exceeding 80% can obtain a higher density, and the drive times of the display elements 11 to 15 that satisfy 2.5 ≦ L / T ≦ 10 are as follows: It could be shorter than other display elements. Furthermore, when the L / T was fabricated with a configuration exceeding 10, it was difficult to obtain a contrast of 5.

1, 1-1, 1-2 substrate 1 'transparent substrate 2, 2-1, 2-2 electrochromic layer 3, 3', 3 ", 3A, 3A ', 3B, 3B', 3C, 3C ', 3D 3D 'electrode 3-1, 3-2 electrode group 4 white scattering layer 5 bank 6-1, 6-2 nanoporous layer 7 contact hole 8 colored region 9 transparent electrode 10 partition 11 transparent substrate L between electrode pair Distance T Electrochromic layer thickness

Claims (9)

In an electrochromic display element having at least an electrode provided in a predetermined pattern on a single substrate and an electrochromic layer, the electrode is composed of a pair of electrodes arranged at opposing positions on the same plane. A pixel electrode forming one pixel, and by causing a potential difference between the pair of electrodes, the electrochromic layer is colored or decolored, and
A display element comprising an electrically insulating bank between a pair of the pixel electrodes forming one pixel and the other pixel electrodes.   2. The electrochromic display unit comprising an electrode and an electrochromic layer provided in a predetermined pattern on the one substrate has a structure in which two or more electrochromic display units are laminated. The display element as described in.   The display element according to claim 1, further comprising a white scattering layer.   The display element according to claim 1, wherein the electrochromic layer has a nanoporous layer. The display element according to any one of claims 1 to 4, wherein the electrochromic layer contains a compound represented by the following general formula (L) as an electrochromic compound.
[Wherein, Rl ₁ represents a substituted or unsubstituted aryl group, and Rl ₂ and Rl ₃ each represent a hydrogen atom or a substituent. X represents> N—Rl ₄ , an oxygen atom or a sulfur atom, and Rl ₄ represents a hydrogen atom or a substituent. ] The display device according to claim 5, wherein the compound represented by the general formula (L) is a compound represented by the following general formula (L2).
Wherein Rl ₂₁ and Rl ₂₂ each represents an aliphatic group, an aliphatic oxy group, an acylamino group, a carbamoyl group, an acyl group, a sulfonamide group or a sulfamoyl group, and Rl ₂₃ represents an aromatic group or an aromatic heterocyclic group Rl ₂₄ represents a hydrogen atom, an aliphatic group, an aromatic group or an aromatic heterocyclic group, and Rl ₂₅ represents a hydrogen atom, an aliphatic group, an aromatic group or an acyl group. ]   The at least one layer of the electrochromic layer contains a metal species that can be electrically dissolved or deposited to display substantially transparent and black with respect to visible light. The display element according to any one of the above.   When observed from the viewing side, the total area of the colored region for performing colored display composed of the electrode pairs arranged on the same plane on the same plane is 70% or more of the entire display region, The display element according to any one of claims 1 to 7.   When the thickness of the electrochromic layer is T (μm) and the distance between the corresponding electrode pairs is L (μm), L / T is 2.5 or more and 10.0 or less. The display element of any one of Claim 1 to 8.