JP2010164683A - Display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display element of stable display quality with high density, hardly causing uneven density of an image. <P>SOLUTION: In this display element, an electrolytic layer containing silver or a compound containing silver in a chemical structure is provided between a pair of counter electrodes disposed on a resin substrate, and an electric field is applied between the counter electrodes to cause dissolution and deposition of silver and display an image. At least one of the counter electrodes is a transparent electrode mainly composed of metal oxide, and an electrically inactive compound having a functional group causing ionic bond or coordinate bond to a silver ion in the electrolytic layer exists on the surface of the transparent electrode. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrochemical display element utilizing silver dissolution precipitation.

  In recent years, with the increase in the operating speed of personal computers, the spread of network infrastructure, the increase in capacity and price of data storage, information such as documents and images provided on printed paper on paper has become easier to use electronic information. Opportunities to obtain and browse electronic information are increasing more and more.

  As a means for browsing such electronic information, a conventional liquid crystal display or CRT, and in recent years, a light emitting type such as an organic EL display is mainly used. In particular, when the electronic information is document information, it is relatively long time. It is necessary to pay close attention to this browsing means, and these actions are not human-friendly means. Generally, as a disadvantage of the light-emitting display, eyes flicker due to flickering, inconvenient to carry, reading posture is limited, It is known that it is necessary to adjust the line of sight to a still screen, and that power consumption increases when read for a long time.

  As a display means to compensate for these drawbacks, a reflection type display having a so-called memory property that uses external light and does not consume power for image retention is known. However, it has sufficient performance for the following reasons. It's hard to say.

  That is, the method using a polarizing plate such as a reflective liquid crystal has a low reflectance of about 40%, which makes it difficult to display white, and it is difficult to say that many of the manufacturing methods used to manufacture the constituent members are simple. In addition, the polymer dispersed liquid crystal requires a high voltage and utilizes the difference in refractive index between organic substances, so that the resulting image has insufficient contrast. In addition, the polymer network type liquid crystal has problems such as a high driving voltage and a complicated TFT circuit required to improve the memory performance. In addition, a display element based on electrophoresis requires a high voltage of 10 V or more, and there is a concern about durability due to electrophoretic particle aggregation.

  As a display method for solving the disadvantages of each of the above-mentioned methods, an electrochromic display element (hereinafter abbreviated as EC method), an electrodeposition method (hereinafter abbreviated as ED method) using dissolution precipitation of metal or metal salt, etc. The electrochemical method is known. These systems have an advantage that they can be formed with a simple element configuration and can be driven at a low voltage of 3 V or less. The EC method enables full color display by selecting an electrochromic material, and the ED method has advantages such as excellent black and white contrast and black quality, and various methods have been disclosed (for example, patent documents). 1-3.)

  Generally known EC or ED display elements have a color image or black-and-white color caused by direct contact between the electrode and the electrolyte, and the exchange of electrons at the electrode interface to cause color disappearance and dissolution and precipitation of the metal. Is displayed. Further, a method of further forming an electron conductive layer on the electrode surface is also known (see, for example, Patent Document 4). Even in that case, the electron conductive layer is intended to assist the transfer of electrons from the electrode, and it is considered that the transfer of electrons occurs at the interface of the electron conductive layer.

  However, since the reaction by direct exchange of electrons occurs only at the interface of the electrode or the electron conductive layer, the interface of the electrode or the electron conductive layer is covered with a reactant (deposited metal in the ED method). In that case, it was observed that no further reaction occurred. That is, even if the initial image formation speed is good, it is difficult to obtain a higher color density. In addition, it has been observed that fine unevenness exists on the surface of an electrode such as ITO, and unevenness in image density is caused by charge concentration on the protruding part.

U.S. Pat. No. 4,240,716 Japanese Patent No. 3428603 JP 2003-241227 A Japanese Patent Laid-Open No. 10-30181

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a display element having a high display density and a stable display quality that hardly causes uneven image density.

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

  1. Between the pair of counter electrodes provided on the resin substrate, there is an electrolyte layer containing silver or a compound containing silver in the chemical structure, and an electric field is applied between the counter electrodes to cause dissolution and precipitation of silver. In the display element that performs image display, at least one of the counter electrodes is a transparent electrode containing a metal oxide as a main component, and is ion-bonded or coordinated with silver ions in the electrolyte layer on the surface of the transparent electrode. A display element, characterized in that there is an electrically inactive compound having a functional group that can be formed.

  2. 2. The functional group capable of ionic bonding or coordination bonding with silver ions in the electrolyte layer is a group selected from a sulfonic acid group, an imidazolium group, an amino group, and a mercapto group. Display element.

  3. 3. The display element according to 1 or 2, wherein the electrically inactive compound having a functional group capable of ionic bonding or coordination bonding with silver ions in the electrolyte layer is a polymer compound. .

  4). 4. The display element according to any one of 1 to 3, wherein the electrolyte layer contains a compound represented by the following general formula (G-1) or (G-2).

General formula (G-1)
_{Rg 11} -S-Rg ₁₂
[Wherein Rg ₁₁ and Rg ₁₂ each represents 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. ]

[Wherein, 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. ]

  According to the present invention, it has been possible to provide a display element having a high display density and a stable display quality that hardly causes uneven image density.

  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 present inventor has an electrolyte layer containing silver or a compound containing silver in a chemical structure between a pair of counter electrodes provided on a resin substrate, In a display element that displays an image by causing dissolution and precipitation of silver by applying an electric field between the counter electrodes, at least one of the counter electrodes is a transparent electrode mainly composed of a metal oxide, and the surface of the transparent electrode In addition, an electrically inactive compound having a functional group capable of ionic bonding or coordination bonding with silver ions is present in the electrolyte layer. As soon as the present invention has been found, it has been found that unevenness is less likely to occur and a display element with stable display quality can be realized.

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

[Compounds having functional groups capable of ionic bonding or coordination bonding with silver ions]
The display element of the present invention is characterized in that an electrically inactive compound having a functional group capable of ionic bonding or coordination bonding with silver ions in the electrolyte layer is present on the transparent electrode surface.

  In the electrolyte layer according to the present invention, silver ions can be ionically bonded or coordinated with each other by dissociating from counter ions in the electrolyte layer by becoming a Bronsted base or Lewis base in the electrolyte layer. This means that it can have an affinity for silver ions that are considered to be positively ionized.

  Silver ions can be localized in the vicinity of the transparent electrode by ionic bonds or coordinate bonds between such functional groups of electrically inactive compounds present on the surface of the transparent electrode and silver ions. Become. Since an ionic bond or a coordinate bond is a loose bond as compared with a covalent bond, when a charge is applied from the electrode, the silver ion can easily receive the charge and precipitate as silver particles. The electrically inactive compound according to the present invention also has a functional group that can be in the state of Bronsted base or Lewis base in the electrolyte layer, so that the charge from the electrode can be easily supplied to silver ions. It is thought that there is. The precipitated silver particles are deposited on the electrode in order to eliminate the affinity with the functional group. It becomes possible to repeat a cycle in which new silver ions are supplied from the surrounding electrolyte layer to the functional group that has become free, and electric charges are supplied thereto. As a result, the efficiency of silver particle formation is unlikely to decrease, and the reaction is continued without being affected by the amount of silver particles on the electrode, so that a higher density image can be obtained.

  It should be noted that the expression "ion bond" and "coordination bond" are used here, but the situation is weaker than ion dissociation in an aqueous solution, and it is thought that the charge is probably localized. You can use this term for convenience.

  Examples of the functional group capable of ionic bonding or coordination bonding with silver ions in such an electrolyte layer include various functional groups capable of becoming a Bronsted base or a Lewis base in the electrolyte layer.

  Specific examples of functional groups capable of ion-bonding with silver ions include carboxylic acid groups, phosphoric acid groups, sulfuric acid groups, amino groups, sulfonic acid groups, mercapto groups, oxalic acid groups, and nitric acid groups. It is not limited to.

  As functional groups that can coordinately bond with silver ions, amino groups, imidazole groups, and the like are known. In imidazole, electrons are localized on a nitrogen atom by extracting a proton at the 1-position. It is widely known that this makes it a good ligand for transition metal ions such as silver ions. Since the nitrogen atom of the amino group also has an unshared electron pair, it can be coordinated to a silver ion.

  Among these functional groups, a sulfonic acid group, an imidazolium group, an amino group, and a mercapto group are particularly preferred because of the balance between the ability to attract silver ions and the ability to transfer charges as ions and release silver ions as silver particles. preferable.

  The electrically inactive compound having a functional group capable of ionic bonding or coordination bonding with silver ions according to the present invention has such a functional group and can be present on or adjacent to the electrode. There is no particular limitation, and known ones can be used. In order to allow the compound to stably exist on the electrode surface, it is possible to take a method such as adsorption onto the electrode, chemical reaction with the electrode surface and bonding, or formation of a film on the electrode surface. A low molecular weight compound can be supported on the electrode surface by a silane coupling reaction or the like, or can be polymerized on the electrode surface. Moreover, it can form suitably by fix | immobilizing the compound known as an ionic liquid on an electrode, or making it polymerize with a matrix formation polymer | macromolecule. Their combination is not particularly defined.

  The part that binds to the silver ions should be some distance away from the electrode surface. That is, silver ions can be easily captured from the electrolyte layer, and the steric influence of the deposited and deposited silver particles can be excluded.

  Therefore, in the case of a high molecular compound, it is more preferable that the functional group which couple | bonds with a silver ion is contained in the form of the side chain.

  An electrically inactive compound having a functional group capable of ionic bonding with silver ions is a compound having non-conductivity. The reason for this is that, in the case of a conductive compound, since it has the same function as the electrode itself, it can transfer charges efficiently, but silver particles are deposited around the compound and do not move. This is because the function of efficiently collecting silver ions in the vicinity is scarce and it is difficult to supply new silver ions.

  Examples of the compound having a sulfonic acid group include polyaniline sulfonic acid, a sulfonic acid group-containing polythiophene polymer such as Espacer 100 manufactured by Showa Denko KK, and perfluorosulfonic acid polymers shown below represented by Nafion manufactured by DuPont. Are known.

  Examples of the compound having an imidazolium group include polybenzimidazole, poly-2,2 ′-(m-phenylene) -5,5′-bibenzimidazole, polyvinylimidazole, and alkylimidazoles described in JP-A-2008-094798. And polybenzimidazole-based proton conductive polymer membranes described in JP-A-2006-339064.

  Examples of the compound having an amino group include ethylenediamine, triethanolamine, glycine, diethylenetriamine, ammonium acetate, triethyltetramine, ethylenediaminetetraacetate, N, N, N ′, N′-tetrakis- (2-aminoethyl) ethylenediamine, 1, Examples thereof include 3-diamino-2-propanol and a polymer compound having an amino group in the structure, but are not limited thereto.

  As a compound having a mercapto group, 2-thioacetic acid-5-mercapto-1,3,4-thiadiazole is used to increase the silanol group by hydrothermal treatment on the surface of the spherical pores of the inorganic porous material, and further using a silane coupling agent. A method for introducing a mercapto group is described in claim 20 of JP-A-2007-311310.

[Silver salt compound]
The silver salt compound according to the present invention is 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, silver ion and the like. There are no particular restrictions on the phase state species such as the solid state, the solubilized state in liquid, and the gas 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 solution 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 the present invention, a silver salt solvent can be used to promote dissolution and precipitation of the silver salt. The silver salt solvent may be any compound that can solubilize silver in the electrolyte. For example, a compound that generates a coordinate bond with silver, a compound that generates a weak covalent bond with silver, a compound containing a chemical structural species that interacts with silver, etc. It is common to use a means for converting to. As the chemical species, halogen atoms, mercapto groups, carboxyl groups, imino groups and the like are known, but in the present invention, compounds containing thioether groups and mercaptoazoles are useful as silver solvents, and This is preferable in that it has little influence on the coexisting compound and can increase the solubility of silver in a solvent. That is, by using a silver salt solvent in combination, erasure of the precipitated silver image is promoted, so that the effect of quick decoloration can be obtained.

(Compound represented by general formula (G-1) or (G-2))
In the display element of this invention, it is preferable that an electrolyte layer contains the compound represented by the following general formula (G-1) or (G-2).

  The mercapto compound represented by the general formula (G-1) and the thioether compound represented by the general formula (G-2) according to the present invention cause dissolution and precipitation of silver in the present invention. It is a compound that promotes solubilization of silver.

  In general, in order to cause dissolution and precipitation of silver, it is necessary to solubilize silver in the electrolyte. For example, a compound that generates a coordinate bond with silver, a compound that generates a weak covalent bond with silver Alternatively, compounds containing chemical structural species that interact with silver are useful. As the chemical structural species, halogen atoms, mercapto groups, carboxyl groups, imino groups and the like are known, but in the present invention, compounds containing thioether groups and mercaptoazoles are useful as silver solvents and It has a feature that it has little influence on coexisting compounds and high solubility in a solvent.

In the general formula (G-1), Rg ₁₁ and Rg ₁₂ each represent a substituted or unsubstituted hydrocarbon group. These hydrocarbon groups may contain one or more nitrogen atoms, oxygen atoms, phosphorus atoms, sulfur atoms, and halogen atoms, and Rg ₁₁ and Rg ₁₂ may be linked to each other to form a cyclic structure.

In the 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.

In the general formula (G-1), Rg ₁₁ and Rg ₁₂ each represent a substituted or unsubstituted hydrocarbon group. 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 the group that can be substituted with a hydrocarbon group include an amino group, a guanidino group, a quaternary amino group, a hydroxyl group, a halogen compound, a carboxylic acid group, a carboxylate group, an amide group, a sulfinic acid group, a sulfonic acid group, and a sulfate. 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), 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.

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.

  Examples of the nitrogen-containing heterocycle having Z as a constituent in general formula (G-2) include, for example, a tetrazole ring, a triazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, an indole ring, an oxazole ring, a benzoxazole ring, Examples include a benzimidazole ring, a benzothiazole ring, a benzoselenazole ring, and a naphthoxazole ring.

In the general formula (G-2), examples of the specific group represented by Rg ₂₁ include a halogen atom (eg, fluorine atom, chlorine atom, bromine atom, iodine atom) alkyl group (eg, methyl, ethyl, propyl). I-propyl, butyl, t-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, octyl, dodecyl, hydroxyethyl, methoxyethyl, trifluoromethyl, benzyl, etc.), aryl group (for example, phenyl, naphthyl, etc.), alkylcarboxylic Amido group (eg, acetylamino, propionylamino, butyroylamino, etc.), arylcarbonamide group (eg, benzoylamino, etc.), alkylsulfonamide group (eg, methanesulfonylamino group, ethanesulfonylamino group, etc.), arylsulfone An amide group (eg , Benzenesulfonylamino group, toluenesulfonylamino group etc.), aryloxy group (eg phenoxy etc.), alkylthio group (eg methylthio, ethylthio, butylthio etc.), arylthio group (eg phenylthio group, tolylthio group etc.), alkyl Carbamoyl group (for example, methylcarbamoyl, dimethylcarbamoyl, ethylcarbamoyl, diethylcarbamoyl, dibutylcarbamoyl, piperidylcarbamoyl, morpholylcarbamoyl, etc.), arylcarbamoyl group (for example, phenylcarbamoyl, methylphenylcarbamoyl, ethylphenylcarbamoyl, benzylphenylcarbamoyl, etc.) Alkylsulfamoyl groups (eg methylsulfamoyl, dimethylsulfamoyl, ethylsulfamoyl, diethyl) Sulfamoyl, dibutylsulfamoyl, piperidylsulfamoyl, morpholylsulfamoyl, etc.), arylsulfamoyl groups (eg, phenylsulfamoyl, methylphenylsulfamoyl, ethylphenylsulfamoyl, benzylphenylsulfamoyl) Etc.), alkylsulfonyl groups (eg, methanesulfonyl group, ethanesulfonyl group, etc.), arylsulfonyl groups (eg, phenylsulfonyl, 4-chlorophenylsulfonyl, p-toluenesulfonyl, etc.) alkoxycarbonyl groups (eg, methoxycarbonyl, ethoxycarbonyl, etc.) , Butoxycarbonyl etc.), aryloxycarbonyl group (eg phenoxycarbonyl etc.), alkylcarbonyl group (eg acetyl, propionyl, butyroyl etc.), aryl Rubonyl group (for example, benzoyl group, alkylbenzoyl group, etc.), acyloxy group (for example, acetyloxy, propionyloxy, butyroyloxy, etc.), heterocyclic group (for example, oxazole ring, thiazole ring, triazole ring, selenazole ring, tetrazole ring, Oxadiazole ring, thiadiazole ring, thiazine ring, triazine ring, benzoxazole ring, benzthiazole ring, indolenine ring, benzselenazole ring, naphthothiazole ring, triazaindolizine ring, diazaindolizine ring, tetraazaind Lysine 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, G2-18, and G2-19 are particularly preferable from the viewpoint that the object and effects of the present invention can be exhibited.

〔solvent〕
In the electrolyte layer according to the present invention, as a solvent, a solvent that is generally used in electrochemical cells and batteries and that can dissolve various additives such as a metal salt compound and a promoter 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 electrolyte 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, Methoxyacetonitrile, dimethylacetamide, methylpyrrolidinone, dimethyl sulfoxide, dioxolane, sulfolane, trimethyl phosphate and triethyl phosphate are preferred. The solvent may be used alone or in combination of two or more.

  In the present invention, particularly preferably used solvents are compounds represented by the following general formula (S1) or (S2).

  <Compounds Represented by General Formulas (S1) and (S2)>

In the general formula (S1), L represents an oxygen atom or an alkylene group, and Rs ₁₁ to Rs ₁₄ each represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group, or an alkoxy group.

In the general formula (S2), Rs ₂₁ and Rs ₂₂ each represents an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group, or an alkoxy group.

  First, the detail of the compound represented by general formula (S1) is demonstrated.

In the general formula (S1), L represents an oxygen atom or CH ₂ , and Rs ₁₁ to Rs ₁₄ each represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group, or an alkoxy group, These substituents may be further substituted with an arbitrary substituent.

  Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, tert-butyl, pentyl, hexyl, octyl, dodecyl, tridecyl, tetradecyl, pentadecyl, and the like as aryl groups. Examples of the cycloalkyl group such as phenyl group, naphthyl group and the like include, for example, a cyclopentyl group, cyclohexyl group and the like, an alkoxyalkyl group, for example, a β-methoxyethyl group, a γ-methoxypropyl group and the like, as an alkoxy group, Examples thereof include a methoxy group, an ethoxy group, a propyloxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, and a dodecyloxy group.

  Hereinafter, although the specific example of a compound represented by general formula (S1) is shown, in this invention, it is not limited only to these illustrated compounds.

  Next, details of the compound represented by formula (S2) according to the present invention will be described.

In the general formula (S2), Rs ₂₁ and Rs ₂₂ each represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group, or an alkoxy group.

  Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, tert-butyl, pentyl, hexyl, octyl, dodecyl, tridecyl, tetradecyl, pentadecyl, and the like as aryl groups. Examples of the cycloalkyl group such as phenyl group, naphthyl group and the like include, for example, a cyclopentyl group, cyclohexyl group and the like, an alkoxyalkyl group, for example, a β-methoxyethyl group, a γ-methoxypropyl group and the like, as an alkoxy group, Examples thereof include a methoxy group, an ethoxy group, a propyloxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, and a dodecyloxy group.

  Hereinafter, although the specific example of a compound represented by general formula (S2) is shown, in this invention, it is not limited only to these illustrated compounds.

  Of the compounds represented by the general formulas (S1) and (S2) exemplified above, the exemplary compounds (S1-1), (S1-2), and (S2-3) are particularly preferable.

  The compounds represented by the general formulas (S1) and (S2) according to the present invention are one type of electrolyte solvent. However, in the display element of the present invention, another solvent is used as long as the object effects of the present invention are not impaired. Can be used together. Specifically, tetramethylurea, sulfolane, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone, 2- (N-methyl) -2-pyrrolidinone, hexamethylphosphortriamide, N-methylpropionamide, N, N-dimethylacetamide, N-methylacetamide, N, N dimethylformamide, N-methylformamide, butyronitrile, propionitrile, acetonitrile, acetylacetone, 4-methyl-2-pentanone, 2-butanol, 1-butanol, 2 -Propanol, 1-propanol, ethanol, methanol, acetic anhydride, ethyl acetate, ethyl propionate, dimethoxyethane, diethoxyfuran, tetrahydrofuran, ethylene glycol, diethylene glycol, triethylene glycol monobuty Ether, water and the like. Among these solvents, it is preferable to include at least one solvent having a freezing point of −20 ° C. or lower and a boiling point of 120 ° C. or higher.

  Furthermore, as a solvent which can be used in the present invention, J.P. A. Riddick, W.M. B. Bunger, T.A. K. Sakano, “Organic Solvents”, 4th ed. , John Wiley & Sons (1986). Marcus, “Ion Solvation”, John Wiley & Sons (1985), C.I. Reichardt, “Solvents and Solvent Effects in Chemistry”, 2nd ed. VCH (1988), G .; J. et al. Janz, R.A. P. T.A. Tomkins, “Nonqueous Electronics Handbook”, Vol. 1, Academic Press (1972).

  In the present invention, the electrolyte solvent may be a single type or a mixture of solvents, but a mixed solvent containing ethylene carbonate is preferred. The addition amount of ethylene carbonate is preferably 10% by mass or more and 90% by mass or less of the total electrolyte solvent mass. A particularly preferable electrolyte solvent is a mixed solvent having a mass ratio of propylene carbonate / ethylene carbonate of 7/3 to 3/7. When the propylene carbonate ratio is larger than 7/3, the ionic conductivity is inferior and the response speed is lowered. When the propylene carbonate ratio is smaller than 3/7, the electrolyte tends to be deposited at a low temperature.

〔Electrolytes〕
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.

Specific examples of the salts include halogen ions, SCN ⁻ , ClO ₄ ⁻ , BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , PF _{^{6 -, AsF 6 -, CH}} 3 COO -, CH 3 (C 6 H 4) SO 3 -, and _{(C 2 F 5 SO 2)} 3 C - Li salt having a counter anion selected from, Na salt or K salt is mentioned.

Further, halogen ions, SCN ⁻ , ClO ₄ ⁻ , BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , PF ₆ ⁻ , AsF _{6 ^{-, CH 3 COO -, CH}} 3 (C 6 H 4) SO 3 -, and _{(C 2 F 5 SO 2)} 3 C - 4 quaternary ammonium salt having a counter anion selected from, specifically, (CH ₃ ) ₄ NBF ₄ , (C ₂ H ₅ ) ₄ NBF ₄ , (n-C ₄ H ₉ ) ₄ NBF ₄ , (C ₂ H ₅ ) ₄ NBr, (C ₂ H ₅ ) ₄ NClO ₄ , (n- C ₄ H ₉ ) ₄ NClO ₄ , CH ₃ (C ₂ H ₅ ) ₃ NBF ₄ , (CH ₃ ) ₂ (C ₂ H ₅ ) ₂ NBF ₄ , (CH ₃ ) ₄ NSO ₃ CF ₃ , (C ₂ H _{5) 4 NSO 3 CF 3,} (n-C 4 H 9 ₄ NSO ₃ CF _3,
Furthermore,

Etc.

Further, halogen ions, SCN ⁻ , ClO ₄ ⁻ , BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , PF ₆ ⁻ , AsF _{6 ^{-, CH 3 COO -, CH}} 3 (C 6 H 4) SO 3 -, and _{(C 2 F 5 SO 2)} 3 C - phosphonium salt having a counter anion selected from, specifically, _(CH 3) ₄ PBF ₄ , (C ₂ H ₅ ) ₄ PBF ₄ , (C ₃ H ₇ ) ₄ PBF ₄ , (C ₄ H ₉ ) ₄ PBF _{4 and the} like. Moreover, these mixtures can also be used suitably.

The supporting electrolyte of the present invention is preferably a quaternary ammonium salt, particularly preferably a quaternary spiro ammonium salt. The _ClO ⁴ as counter anion ^{_{-, BF 4 -, CF 3}} SO 3 -, (C 2 F 5 SO 2) 2 N -, PF 6 - are preferable, and BF ₄ ^- is preferable.

  The amount of the electrolyte salt used is arbitrary, but in general, the electrolyte salt is present in the solvent as an upper limit of 20 mol / L or less, preferably 10 mol / L or less, more preferably 5 mol / L or less. 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.

  In the case of a solid electrolyte, the following compounds exhibiting electronic conductivity and ionic conductivity can be contained in the electrolyte.

Vinyl fluoride polymer containing perfluorosulfonic acid, polythiophene, polyaniline, polypyrrole, triphenylamines, polyvinylcarbazoles, polymethylphenylsilanes, Cu ₂ S, Ag ₂ S, Cu ₂ Se, AgCrSe _2, etc. Fluorine-containing compounds such as chalcogenides, CaF ₂ , PbF ₂ , SrF ₂ , LaF ₃ , TlSn ₂ F ₅ , CeF ₃ , Li salts such as Li ₂ SO ₄ , Li ₄ SiO ₄ , Li ₃ PO ₄ , ZrO ₂ , CaO , Cd ₂ O ₃ , HfO ₂ , Y ₂ O ₃ , Nb ₂ O ₅ , WO ₃ , Bi ₂ O ₃ , AgBr, AgI, CuCl, CuBr, CuBr, CuI, LiI, LiBr, LiCl, LiAlCl ₄ , LiAlF ₄ , AgSBr, C ₅ H ₅ NHAg ₅ I ₆ , Rb ₄ Cu ₁₆ I Examples thereof include ₇ Cl ₁₃ , Rb ₃ Cu ₇ Cl ₁₀ , LiN, Li ₅ NI ₂ , and Li ₆ NBr ₃ .

(Ionic liquid)
The ionic liquid referred to in the present invention is also called a room temperature molten salt, and is a salt having a melting point of 100 ° C. or lower. This salt is composed of the same number of cations and anions, and there are many substances having a melting point below room temperature depending on the molecular structure, and these are in a liquid state at room temperature without adding any solvent. An ionic liquid has a strong characteristic that it has a strong electrostatic interaction and thus has almost no vapor pressure, and does not evaporate even at high temperatures.

  The ionic liquid used in the present invention 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.

The ionic liquid that can be suitably used in the present invention is represented by the formula Q ⁺ A ⁻ and is 20 to 100 ° C., preferably 20 to 80 ° C., more preferably 20 to 60 ° C., and still more preferably 20 to 40 ° C. In particular, it refers to a salt that exists as a liquid at 20 ° C., and the viscosity (25 ° C.) is not particularly limited as long as it is a melt at normal temperature, but it is preferably 1 to 200 mPa · s. Further, the cation component represented by Q + in the formula is preferably an onium cation, and more preferably an ammonium cation, an imidazolium cation, a pyridinium cation, a sulfonium cation, and a phosphonium cation.

The above-described ionic fluid will be specifically described in detail. As Q ⁺ in the above formula, R ₁ R ₂ R ₃ R ₄ N ⁺ , R ₁ R ₂ R ₃ S ⁺ , R ₁ R ₂ R ₃ R ₄ P ⁺ , R ₁ R ₂ N ⁺ = CR ₃ R ₄ , R ₁ R ₂ P ⁺ = CR ₃ R ₄ [where R ₁ to R ₄ are, independently of one another, hydrogen, saturated or unsaturated carbon C 1 -C 12 alkyl group, a cycloalkyl group having 3 to 8 carbon atoms, an aryl group or an aralkyl group having a carbon number of 7-11 having 6 to 10 carbon _{atoms, R 5 -X- (R 6 -Y-} ) n - (Wherein R ₅ represents an alkyl group having 4 or less carbon atoms, R ₆ represents an alkylene group having 4 or less carbon atoms, X and Y represent an oxygen atom or a sulfur atom, and n represents an integer of 0 to 10). And the group may be substituted] ammonium selected from the group consisting of Phosphonium _{^{ion, R 1 R 2 N + =}} CR 3 -R 7 -R 3 C = N + R 1 R 2, R 1 R 2 S + -R 7 -S + R 1 R 2, R 1 R 2 P + ^{_{= CR 3 -R 7 -R 3 C}} = P + R 1 R 2 ( _wherein, R 1, _{R 2} and _{R 3} are the same as defined above, and _{R 7} is 1 to carbon atoms A quaternary ammonium and / or phosphonium ion selected from the group consisting of 6 alkylene or phenylene groups, which may have a substituent, and nitrogen represented by the following general formula: Examples thereof include nitrogen ions containing 1, 2 or 3 atoms selected from sulfur and phosphorus atoms, ammonium ions derived from sulfur and phosphorus atom-containing heterocycles, sulfonium ions, phosphonium ions, and the like.

Wherein R ₁ and R ₂ are as defined above, and Z is an atom capable of constituting a 4-10 membered ring containing N ⁺ , N ⁺ = C, S ⁺ , P ⁺ or P ⁺ = C And the constituent atoms may have a substituent.

Specific examples of R ₁ to R _{4 in} the above are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, A linear or branched alkyl group such as nonyl and decyl; a cycloalkyl group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl; unsubstituted or halogen atoms (eg, F, Cl, Br, I ), Hydroxyl group, lower alkoxy group (eg, methoxy, ethoxy, propoxy, butoxy, etc.), carboxyl group, acetyl group, propanoyl group, thiol group, lower alkylthio group (eg, methylthio, ethylthio, propylthio, butylthio, etc.) Each group), amino group, lower alkyl Amino group include phenyl having one to three substituents, such as di-lower alkyl amino group, naphthyl, tolyl, aryl group xylyl, and the like aralkyl groups such as benzyl. Further, specific examples of _{R 5} include methyl, ethyl, n- propyl, isopropyl, n- butyl, isobutyl, sec- butyl, and alkyl group such as tert- butyl group, methylene as _{R 6} And alkylene groups such as ethylene, propylene and butylene groups. Furthermore, specific examples of R ₇ include alkylene groups such as methylene, ethylene, propylene, and butylene, and phenylene groups such as phenylene.

Further, A in the formula ^- Examples of the counter anion represented by, hexafluorophosphate, hexafluoroantimonate, hexafluoroarsenate, fluorosulfonate salts, tetrafluoroborate, nitrate, alkyl sulfonate Represents a fluorinated alkyl sulfonate or a hydrogen sulfate.

  Furthermore, WO95 / 18456, JP-A-8-259543, JP-A-2001-243959, Electrochemical Vol.65, No.11, p.923 (1997), EP-716288, J. Org. Electrochem. Soc. , Vol. 143, no. 10, 3099 (1996), Inorg. Chem. The pyridinium salts, imidazolium salts, triazolium salts and the like described in 1996, 35, 1168 to 1178 can be selected and used in a timely manner according to the present invention.

(Solid electrolyte, gel electrolyte)
The electrolyte according to the present invention is not only a solution electrolyte composed of a solvent or an ionic liquid, but also a high-viscosity electrolyte or a gel electrolyte (hereinafter, referred to as a solid electrolyte or a polymer compound containing substantially no solvent). Gel electrolyte) can be used.

  Examples of the solid electrolyte and gel electrolyte applicable to the present invention include a solid electrolyte described in JP-A No. 2002-341387, a polymer solid electrolyte described in JP-A No. 2002-341387, and JP-A No. 2004-20928. A solid polymer electrolyte described in JP-A No. 2004-191945, a solid polymer electrolyte described in JP-A No. 2005-338204, and a polymer described in JP-A No. 2006-323022 Examples thereof include solid electrolytes, solid electrolytes described in JP-A No. 2007-141658, solid electrolytes described in JP-A No. 2007-163865, and gel electrolytes.

[White scattered matter]
In the present invention, a porous white scattering layer containing a white scattering material can be provided from the viewpoint of further increasing display contrast and white display reflectance.

  The porous white scattering layer applicable to the present invention can be formed by applying and drying an aqueous mixture of an aqueous polymer and a white pigment that is substantially insoluble in the electrolyte solvent.

  In the present invention, “substantially insoluble in an electrolyte solvent” is defined as a state in which the dissolved amount per kg of electrolyte solvent 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 a component determination method using a chromatogram or a gas chromatogram.

  In the present invention, examples of the water-based polymer that does not substantially dissolve in the electrolyte solvent include a water-soluble polymer and a polymer dispersed in the water-based solvent.

Examples of water-soluble compounds include proteins such as gelatin and gelatin derivatives, or cellulose derivatives, natural compounds such as starch, gum arabic, dextran, pullulan, and carrageenan polysaccharides, polyvinyl alcohol, polyethylene glycol, polyvinyl pyrrolidone, and acrylamide polymers. And synthetic polymer compounds such as derivatives thereof. As gelatin derivatives, acetylated gelatin, phthalated gelatin, polyvinyl alcohol derivatives as 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. Furthermore, Research Disclosure and those described in 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 (e.g., sodium methacrylate in the vinyl monomer having a methacrylic acid Copolymers with ammonium, potassium acrylate, etc.) are also used. These binders can be used in combination of two or more.

  In the present invention, polyvinyl alcohol, polyethylene glycol, and polyvinylpyrrolidone compounds 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.

  The average molecular weight of the water-based polymer of the present invention is preferably in the range of 10,000 to 2,000,000, more preferably in the range of 30,000 to 500,000 on a weight average basis.

  Examples of the white pigment applicable in 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, or the like may be used alone or in combination, or in a state having voids that change the refractive index in the particles.

In the present invention, among the white particles, titanium dioxide is preferably used. In particular, titanium dioxide surface-treated with an inorganic oxide (Al ₂ O ₃ , AlO (OH), SiO _2, etc.), in addition to these surface treatments. Titanium dioxide that has been treated with an organic substance such as trimethylolethane, triethanolamine acetate, or trimethylcyclosilane is more preferably 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, the water mixture of the water-based compound and the white pigment is preferably in a form in which the white pigment is dispersed in water according to a known dispersion method. The mixing ratio of the aqueous compound / white pigment is preferably 1 to 0.01, more preferably 0.3 to 0.05 in terms of volume ratio.

  The thickness of the porous white scattering layer is preferably in the range of 5 to 50 μm, more preferably in the range of 10 to 30 μm.

  As the alcohol solvent, a compound having high solubility in water such as methanol, ethanol, isopropanol is preferably used, and the mixing ratio with the water / alcohol solvent is preferably in the range of 0.5 to 20 by mass ratio, More preferably, it is the range of 2-10.

  In the present invention, the medium for applying the water mixture of the water-based compound 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 on the electrode surface of at least one of the counter electrodes. It is preferable to give to.

  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.

  As a coating method, it can select suitably from a well-known coating method. For example, air doctor coater, blade coater, rod coater, knife coater, squeeze coater, impregnation coater, reverse roller coater, transfer roller coater, curtain coater, double roller coater, slide hopper coater, gravure coater, kiss roll coater, bead coater, Examples include cast coaters, spray coaters, calendar coaters, and extrusion coaters.

  Drying of the water mixture of the aqueous compound and the white pigment applied on the medium may be performed 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.

  Porous as used in the present invention refers to the formation of a porous white scattering material by applying a water admixture of the water-based compound and the white pigment onto the electrode and drying it, and then the silver or silver is chemically treated on the scattering material. After supplying an electrolyte solution containing the compound contained in the structure, it can be sandwiched between opposing electrodes, giving a potential difference between the opposing electrodes, causing a silver dissolution precipitation reaction, and penetrating ions that can move between the electrodes Tell the state.

  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.

[Thickener added with electrolyte]
In the display element of the present invention, a thickener can be used for the electrolyte. For example, gelatin, gum arabic, poly (vinyl alcohol), hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose acetate, cellulose acetate butyrate, poly ( Vinylpyrrolidone), poly (alkylene glycol), 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 acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (esters), poly (urethanes), phenoxy resins, poly (PVC Redene), poly (epoxide) s, poly (carbonates), poly (vinyl acetate), cellulose esters, poly (amides), hydrophobic transparent binders such as polyvinyl butyral, cellulose acetate, cellulose acetate butyrate, polyester, Examples include polycarbonate, polyacrylic acid, polyurethane and the like.

  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.

[Other additives]
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).

  The types of compounds and their descriptions shown in these three research disclosures are listed below.

Additive RD17643 RD18716 RD308119
Page Classification Page Classification Page Classification Chemical sensitizer 23 III 648 Upper right 96 III
Sensitizing dye 23 IV 648-649 996-8 IV
Desensitizing dye 23 IV 998 IV
Dye 25-26 VIII 649-650 1003 VIII
Development accelerator 29 XXI 648 Upper right Anti-fogging agent / stabilizer
24 IV 649 Upper right 1006-7 VI
Brightener 24 V 998 V
Hardener 26 X 651 Left 1004-5 X
Surfactant 26-7 XI 650 Right 1005-6 XI
Antistatic agent 27 XII 650 Right 1006-7XIII
Plasticizer 27 XII 650 Right 1006 XII
Slipper 27 XII
Matting agent 28 XVI 650 Right 1008-9 XVI
Binder 26 XXII 1003-4 IX
Support 28 XVII 1009 XVII
The above additives may be provided in auxiliary layers such as a protective layer, a filter layer, an antihalation layer, a crossover light cut layer, and a backing layer, and may be contained in these auxiliary layers.

〔substrate〕
The substrate that can be used in the present invention is preferably a transparent substrate. Examples of such a transparent substrate include polyester (for example, polyethylene terephthalate), polyimide, polymethyl methacrylate, polystyrene, polypropylene, polyethylene, and polyamide. Nylon, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyethersulfone, silicone resin, polyacetal resin, fluororesin, cellulose derivative, polyolefin and other polymer films, plate substrates, glass substrates, and the like are preferably used. The transparent substrate used in the present invention refers to a substrate having a transmittance for visible light of at least 50%.

  Further, as the counter substrate, for example, an opaque substrate such as an inorganic substrate such as a metal substrate or a ceramic substrate can be used.

〔electrode〕
(Display side transparent electrode)
Of the counter electrodes, the electrode positioned on the display side is preferably a transparent electrode.

  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 addition, polythiophene, polypyrrole, polyaniline, polyacetylene, polyparaphenylene, polyselenophenylene, etc., and their modifying compounds can be used alone or in combination.

  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.

(Transparent porous electrode)
As one embodiment of the transparent electrode, a nanoporous electrode having a nanoporous structure can be provided on the transparent electrode. This nanoporous electrode is substantially transparent when a display element is formed, and can carry an electroactive substance such as an electrochromic dye.

  The nanoporous structure as used in the present invention refers to a state in which an infinite number of nanometer-sized pores exist in a layer and ionic species contained in the electrolyte can move within the nanoporous structure.

  As a method for forming such a nanoporous electrode, a dispersion containing fine particles constituting the nanoporous electrode is formed in layers by an ink jet method, a screen printing method, a blade coating method, etc., and then heated at a predetermined temperature. A method of making porous by drying, baking, a method of making nanoporous by anodizing or photoelectrochemical etching after forming an electrode layer by sputtering, CVD, atmospheric pressure plasma, etc. Is mentioned. Also, the sol-gel method, Adv. Mater. It can also be formed by the method described in 2006, 18, 2980-2983.

The main components of the fine particles constituting the nanoporous electrode are metals such as Cu, Al, Pt, Ag, Pd and Au, metal oxides such as ITO, SnO ₂ , TiO ₂ and ZnO, carbon nanotubes, glassy carbon, and diamond. It can be selected from carbon electrodes such as like carbon and nitrogen-containing carbon, and is preferably selected from metal oxides such as ITO, SnO ₂ , TiO ₂ , and ZnO.

  In order for the nanoporous electrode to have transparency, it is preferable to use fine particles having an average particle diameter of about 5 nm to 10 μm. As the shape of the fine particles, those having an arbitrary shape such as an indefinite shape, a needle shape, and a spherical shape can be used.

  The film thickness of the nanoporous electrode is preferably in the range of 0.1 to 10 μm, more preferably in the range of 0.25 to 5 μm.

(Grid electrode: auxiliary electrode)
An auxiliary electrode can be attached to at least one of the counter electrodes according to the present invention.

  The auxiliary electrode is preferably made of a material having a lower electrical resistance than the main electrode portion. For example, metals such as platinum, gold, silver, copper, aluminum, zinc, nickel, titanium, and bismuth and alloys thereof can be preferably used.

  The auxiliary electrode can be installed either between the main electrode portion and the substrate, or on the surface of the main electrode portion opposite to the substrate. In any case, it is only necessary that the auxiliary electrode is electrically connected to the main electrode portion.

  There are no particular restrictions on the arrangement pattern of the auxiliary electrodes. It can be appropriately formed according to the required performance, such as linear, mesh, or circular. When the main electrode part is divided into a plurality of parts, the divided electrode parts may be connected to each other. However, in the case where the main electrode portion is a transparent electrode provided on the substrate on the display side, the auxiliary electrode is required to be provided with a shape and frequency that do not impair the visibility of the display element.

  As a method of forming the auxiliary electrode, a known method can be used. For example, a patterning method by photolithography, a printing method, an ink jet method, electrolytic plating or electroless plating, or a method of forming a pattern by exposing and developing using a silver salt photosensitive material may be used.

  The line width and line spacing of the auxiliary electrode pattern may be arbitrary values, but the line width needs to be increased in order to increase the conductivity. On the other hand, when an auxiliary electrode is attached to the transparent electrode, from the viewpoint of visibility, the area coverage of the auxiliary electrode viewed from the display element observation side is preferably 30% or less, and more preferably 10% or less.

  Thus, from the viewpoint of transmittance and conductivity, the line width of the auxiliary electrode is preferably 1 μm or more and 100 μm or less, and the line interval is preferably 50 μm to 1000 μm.

(Method of forming electrode)
A known method can be used to form the transparent electrode and the metal auxiliary electrode. For example, a method of depositing a mask on a substrate by a sputtering method or the like, a method of patterning by a photolithography method after forming the entire surface, and the like can be given.

  Electrodes can also be formed by electrolytic plating, electroless plating, printing methods, and ink jet methods.

  After forming an electrode pattern including a catalyst layer having a monomer polymerization ability on a substrate using an inkjet method, a monomer component that is polymerized by the catalyst and becomes a conductive polymer layer after polymerization is added, It is also possible to form a metal electrode pattern by polymerizing and further performing metal plating such as silver on the conductive polymer layer, and the process is greatly reduced because no photoresist or mask pattern is used. It can be simplified.

  When the electrode material is formed by a coating method, for example, a known method such as a dipping method, a spinner method, a spray method, a roll coater method, a flexographic printing method, a screen printing method, or the like can be used.

  Among the ink jet methods, the following electrostatic ink jet method is capable of continuously printing a highly viscous liquid with high accuracy and is preferably used for forming the transparent electrode and the metal auxiliary electrode of the present invention. The viscosity of the ink is preferably 30 mPa · s or more, and more preferably 100 mPa · s or more.

<Electrostatic inkjet method>
In the display element of the present invention, at least one of the transparent electrode of the composite electrode and the metal auxiliary electrode has a liquid discharge head having a nozzle with an internal diameter of 30 μm or less for discharging a charged liquid, and supplies a solution into the nozzle. It is one of the preferable embodiments that the liquid discharge device is provided with a supply unit that performs the discharge and a discharge voltage application unit that applies a discharge voltage to the solution in the nozzle. Further, it is preferable that the solution in the nozzle is formed by using a discharge device provided with a convex meniscus forming means for forming a state where the solution rises from the nozzle tip.

  In addition, it comprises operation control means for controlling application of drive voltage for driving the convex meniscus forming means and application of discharge voltage by the discharge voltage application means, and this operation control means applies application of the discharge voltage by the discharge voltage application means. It is also preferable to use a liquid ejection apparatus having a first ejection control unit that applies a driving voltage to the convex meniscus forming means when ejecting liquid droplets.

  In addition, an operation control unit that controls driving of the convex meniscus forming unit and voltage application by the discharge voltage applying unit is provided, and the operation control unit includes an operation for raising the solution by the convex meniscus forming unit, and application of the discharge voltage. A liquid discharge device having a second discharge control unit that synchronizes the liquid, and the operation control means includes a liquid level at the tip of the nozzle after the swell operation of the solution and the application of the discharge voltage. It is also a preferred form to use a liquid ejection apparatus having a liquid level stabilization control unit that performs operation control for drawing in the inside.

  By producing an electrode pattern using such an electrostatic inkjet, it is advantageous that an electrode having excellent on-demand characteristics, little waste material, and excellent dimensional accuracy can be obtained.

[Other components of the display element]
In the display element of the present invention, a sealant, a columnar structure, and spacer particles can be used as necessary.

  Sealing agent is for sealing so that it does not leak outside and is also called sealing agent. Epoxy resin, urethane resin, acrylic resin, vinyl acetate resin, ene-thiol resin, silicon resin, modified resin A curing type such as a polymer resin, such as a thermosetting type, a photocurable type, a moisture curable type, and an anaerobic curable type can be used.

  The columnar structure provides strong self-holding (strength) between the substrates, for example, a columnar body, a quadrangular columnar body, an elliptical columnar body, a trapezoidal array arranged in a predetermined pattern such as a lattice arrangement. A columnar structure such as a columnar body can be given. Alternatively, stripes arranged at predetermined intervals may be used. This columnar structure is not a random array, but can be properly maintained at intervals of the substrate, such as an evenly spaced array, an array in which the interval gradually changes, and an array in which a predetermined arrangement pattern is repeated at a constant period. The arrangement is preferably considered so as not to disturb the display. If the ratio of the area occupied by the columnar structure in the display area of the display element is 1 to 40%, a practically sufficient strength as a display element can be obtained.

  A spacer may be provided between the pair of substrates for uniformly maintaining a gap between the substrates. Examples of the spacer include a sphere made of resin or inorganic oxide. Further, a fixed spacer having a surface coated with a thermoplastic resin is also preferably used. In order to hold the gap between the substrates uniformly, only the columnar structure may be provided, but both the spacer and the columnar structure may be provided, or instead of the columnar structure, only the spacer is used as the space holding member. May be used. The diameter of the spacer is equal to or less than the height of the columnar structure, preferably equal to the height. When the columnar structure is not formed, the diameter of the spacer corresponds to the thickness of the cell gap.

[Display element driving method]
The driving operation of the display element of the present invention may be simple matrix driving or active matrix driving. The simple matrix driving in the present invention is a driving method in which a current is sequentially applied to a circuit in which a positive line including a plurality of positive electrodes and a negative electrode line including a plurality of negative electrodes are opposed to each other in a vertical direction. Say that. By using simple matrix driving, there is an advantage that the circuit configuration and driving IC can be simplified and manufactured at low cost. The active matrix drive is a system in which scanning lines, data lines, and current supply lines are formed in a grid pattern, and are driven by TFT circuits provided in each grid pattern. Since switching can be performed for each pixel, there are merits such as gradation and memory function. For example, a circuit described in FIG. 5 of JP-A-2004-29327 can be used.

[Product application]
The display element of the present invention can be used in an electronic book field, an ID card field, a public field, a traffic field, a broadcast field, a payment field, a distribution logistics field, and the like. Specifically, keys for doors, student ID cards, employee ID cards, various membership cards, convenience store cards, department store cards, vending machine cards, gas station cards, subway and railway cards, bus cards, Cash cards, credit cards, highway cards, driver's licenses, hospital examination cards, electronic medical records, health insurance cards, Basic Resident Registers, passports, electronic books, 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.

<< Preparation of electrolyte solution >>
[Preparation of electrolyte solution 1]
A solution prepared by adding 1 part by mass of silver iodide (AgI), 2 parts by mass of sodium iodide (NaI) and 10 parts by mass of polyvinylpyrrolidone (PVP, average molecular weight 100,000) in 25 parts by mass of dimethyl sulfoxide and heating and dissolving. In addition, 12 parts by mass of titanium dioxide having an average particle diameter of about 0.25 μm was added and dispersed with an ultrasonic disperser to prepare an electrolyte solution 1.

[Preparation of electrolyte solution 2]
In 25 parts by mass of dimethyl sulfoxide, 1 part by mass of silver p-toluenesulfonate, 2 parts by mass of 3-mercapto-1,2,4-triazole and 10 parts by mass of polyvinylpyrrolidone (PVP, average molecular weight 100,000) are added. Then, 12 parts by mass of titanium dioxide having an average particle size of about 0.25 μm was added to the solution dissolved by heating and dispersed with an ultrasonic disperser to prepare an electrolyte solution 2.

[Preparation of electrolyte solution 3]
In 25 parts by mass of dimethyl sulfoxide, 1 part by mass of silver p-toluenesulfonate, 2 parts by mass of 3,6-dithia-1,8-octanediol and 10 parts by mass of polyvinylpyrrolidone (PVP, average molecular weight 100,000) are added. Then, 12 parts by mass of titanium dioxide having an average particle diameter of about 0.25 μm was added to the heat-dissolved liquid, and dispersed with an ultrasonic disperser to prepare an electrolyte solution 3.

<Production of electrode>
[Preparation of electrode 1]
An ITO film having a pitch of 145 μm and an electrode width of 130 μm was formed on a 10 cm × 10 cm glass substrate having a thickness of 1.5 mm according to a known method to obtain a transparent electrode (electrode 1).

[Production of electrode 2]
A silver-palladium electrode having an electrode thickness of 0.8 μm, a pitch of 145 μm, and an electrode interval of 130 μm was formed on a glass substrate having a thickness of 1.5 mm and a size of 10 cm × 10 cm using a known method.

[Production of Electrode 1-a]
Using a conventionally known electrolytic polymerization method in a hydrochloric acid aqueous solution, aniline was electrolytically polymerized on the electrode 1 to form a polyaniline film to obtain an electrode 1-a.

[Production of Electrode 1-b]
A film of polyaniline sulfonic acid was formed on electrode 1 by spin coating using aquaPASS-01x (see the following structural formula, manufactured by Mitsubishi Rayon Co., Ltd.), which is an aqueous polyaniline sulfonic acid solution, to obtain electrode 1-b.

[Production of Electrode 1-c]
A coating of a sulfonic acid group-containing polythiophene polymer was formed on the electrode 1 using Espacer 100 (manufactured by Showa Denko KK), which is a polythiophene derivative, to obtain an electrode 1-c.

[Production of Electrode 1-d]
Azobisisobutyronitrile was added to N-vinylimidazolium bromide prepared according to the method described in JP-A-2000-11753 in a proportion of 0.7% by mass with respect to the vinyl group, and 65 ° C. To obtain an electrode 1-d in which an N-vinylimidazolium polymer was formed on the electrode 1 by radical polymerization for 3 hours.

[Production of Electrode 1-e]
0.1 part by mass of 3-aminopropyldiethoxymethylsilane (manufactured by Tokyo Chemical Industry Co., Ltd.) is dissolved in 20 parts by mass of pure water, and the electrode 1 is immersed in this solution for 1 hour, and then pure water and ethanol And then heat-treated at 100 ° C. for 1 hour.

  Heat-treated electrode 1 was dissolved in 10 parts by mass of dimethylformamide in an amount of 0.3 parts by mass of 2-thioacetic acid-5-mercapto-1,3,4-thiadiazole (manufactured by Toyo Kasei Kogyo Co., Ltd.). It was immersed and left at room temperature for about 3 hours to cause a silane coupling reaction to obtain an electrode 1-d.

[Production of Electrode 1-f]
1,3-bis (dimethylbenzylammonium) isopropyl acrylate chlorine prepared according to the method described in JP-A-2002-371041 is polymerized on the electrode 1 using benzyl chloride, and the electrode 1-f is formed. Obtained.

[Preparation of electrode 1-g]
Using a Nafion dispersion (5% by mass, manufactured by DuPont), which is a perfluorosulfonic acid polymer, a perfluorosulfonic acid polymer film was formed on the electrode 1 to obtain an electrode 1-g.

[Production of Electrode 1-h]
A hydrophilic polymer described in Synthesis Example 5 of JP-A-2008-260272 was used as an aqueous solution, spin-coated on the electrode 1, and then dried at 80 ° C. for 5 minutes to form an electrode 1-h.

<< Production of display element >>
The periphery of each of the electrodes 1 and 1-a to 1-h is trimmed with an olefin-based sealant containing 10% of glass spherical bead spacers having an average particle diameter of 30 μm as a volume fraction. An empty cell was prepared by pasting and heating and pressing. Into this empty cell, the electrolyte solution shown in Table 1 was vacuum-injected, and the inlet was sealed with an epoxy-based ultraviolet curable resin, and display elements 1 to 15 were produced. Table 1 shows the types of electrodes and electrolyte solutions used for manufacturing each display element.

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

(Measurement of initial arrival reflectance)
Connect both electrodes of each display element to both terminals of the constant voltage power supply and apply a voltage of -1.5 V to the display-side electrode, and change the reflectance of the display part of each display element by Konica Minolta Sensing Co., Ltd. And a spectrocolorimeter CM-3700d. The reflectance at the time when the change in the reflectance value almost disappeared was defined as the initial reached reflectance. The lower the initial arrival reflectance, the higher the display density.

[Durability evaluation: Measurement of ultimate reflectance fluctuation]
Connect both electrodes of each display element to both terminals of the constant voltage power supply, apply a voltage of -1.5 V to the display-side electrode to perform black display, and then apply +1.5 V to the display-side electrode. Applied to erase the color. The voltage application of -1.5V for 1 second and the voltage application of + 1.5V for 1 second are repeated 300 times, and then black display by -1.5V is performed, and the ultimate reflection after continuous operation is performed in the same manner as described above. The ratio was measured, and the difference ΔR (%) from the measured initial reached reflectance was calculated and used as a measure of durability. It represents that it is excellent in durability, so that (DELTA) R (%) is small.

  The results obtained as described above are shown in Table 1.

  As is clear from the results shown in Table 1, it can be seen that the display element having the configuration defined in the present invention has a higher display density and superior durability compared to the comparative example.

Claims (4)

  There is an electrolyte layer containing silver or a compound containing silver in the chemical structure between a pair of counter electrodes provided on the resin substrate, and an electric field is applied between the counter electrodes to cause dissolution and precipitation of silver. In the display element that performs image display, at least one of the counter electrodes is a transparent electrode containing a metal oxide as a main component, and is ion-bonded or coordinated with silver ions in the electrolyte layer on the surface of the transparent electrode. A display element, characterized in that there is an electrically inactive compound having a functional group that can be formed.   The functional group capable of ionic bonding or coordination bonding with silver ions in the electrolyte layer is a group selected from a sulfonic acid group, an imidazolium group, an amino group, and a mercapto group. The display element as described.   The display according to claim 1 or 2, wherein the electrically inactive compound having a functional group capable of ionic bonding or coordination bonding with silver ions in the electrolyte layer is a polymer compound. element. The display element according to any one of claims 1 to 3, wherein the electrolyte layer contains a compound represented by the following general formula (G-1) or (G-2).
General formula (G-1)
_{Rg 11} -S-Rg ₁₂
[Wherein Rg ₁₁ and Rg ₁₂ each represents 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. ]

[Wherein, 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. ]