JP5158191B2 - Display element - Google Patents

Description

  The present invention relates to a novel electrochemical display element.

  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 using so-called "memory" that uses external light and does not consume power for image retention is known. However, it has sufficient performance for the following reasons. It is hard to say that it has.

  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 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 eliminating the drawbacks of each of the above-described methods, an electrodeposition method (hereinafter, abbreviated as ED method) using dissolution precipitation of metal or metal salt is known. The ED method can be driven at a low voltage of 3 V or less, has advantages such as a simple cell configuration, excellent black-white contrast and black quality, and various methods have been disclosed (for example, Patent Document 1). -3)).

  Improvement of the rewriting speed of an ED display element is always desired. For example, Patent Document 4 studies to improve the rewriting speed by using an amide compound as an electrolyte solvent.

As a result of examining the technique disclosed in Patent Document 4 in detail, when the amide compound is used as an electrolyte solvent, the inventor improves the rewrite speed when displaying black, but rewrites when displaying white. It has been found that the speed improvement effect is small or the rewriting speed decreases.
U.S. Pat. No. 4,240,716 Japanese Patent No. 3428603 JP 2003-241227 A JP 2001-510590 A

  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 that can be driven with a simple member configuration, a low voltage, and has a fast black display and white display rewrite speed.

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

  1. Between the counter electrodes, an electrolyte containing a compound represented by the following general formula (1) and a metal salt compound and a white scattering material are included, and at least one counter electrode is represented by the following general formula (A). A display element, wherein a compound or a compound represented by the general formula (B) is immobilized, and displays black and white by applying a voltage between the counter electrodes.

[Wherein, R ₁ represents an alkyl group, a cycloalkyl group, an alkenyl group, a carbonyl group, a carboxyl group or an aryl group, and R ₂ represents a hydrogen atom or an alkyl group. R ₁ and R ₂ may further have a substituent. The ring represents a 5-membered ring or 6-membered ring containing a nitrogen atom. ]

[Wherein, Ra ₁ , Ra ₂ , Rb ₁ and Rb ₂ each independently represent an aromatic hydrocarbon group, an aromatic heterocyclic group or an aliphatic hydrocarbon group which may have a substituent. Ra ₁ and Ra ₂ , Rb ₁ and Rb ₂ may be connected to each other to form a cyclic structure. ]
2. 2. The display element according to 1 above, wherein the metal salt compound is a silver salt compound.

3. Ra ₁ and Ra ₂ in the general formula (A) and Rb ₁ and Rb _{2 in} the general formula (B) are each an aromatic hydrocarbon group or an aromatic heterocyclic group, 2. The display element according to 2.

4). In the general formula (A), Ra ₁ and Ra ₂ and Rb ₁ and Rb _{2 in} the general formula (B) are each an aromatic hydrocarbon group substituted with an electron-withdrawing group or an electron-deficient aromatic heterocyclic ring. 4. The display element according to any one of items 1 to 3, wherein the display element is a group.

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

General formula (2)
R ⁵ -S-R ⁶
[Wherein, R ⁵ and R ⁶ each represents a substituted or unsubstituted hydrocarbon group. However, when a ring containing an S atom is formed, an aromatic group is not taken. ]

[Wherein, M represents a hydrogen atom, a metal atom or quaternary ammonium. Z represents a nitrogen-containing heterocyclic ring. n represents an integer of 0 to 5, and R ⁷ 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 aryloxy group 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, aryl Represents an oxycarbonyl 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, each R ⁷ May be the same or different and may be linked to each other to form a condensed ring. ]

  According to the present invention, it is possible to provide a display element that can be driven with a simple member configuration, low voltage, and has a fast rewriting speed for black display and white display.

  Hereinafter, the best mode 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 and a white scattering material containing the compound represented by the general formula (1) and the metal salt compound between the counter electrodes, and The compound represented by the general formula (A) or the compound represented by the general formula (B) is fixed to at least one of the counter electrodes, and by applying a voltage between the counter electrodes, black and It has been found that a display element characterized by displaying white color can realize a display element that can be driven with a simple member configuration, low voltage, and has a fast black display and white display rewrite speed. is there.

  That is, the compound represented by the general formula (A) or (B) according to the present invention is represented by the general formula (A) or (B) by oxidation-reduction on the electrode on the side facing the display side. Compared to the case where there is no compound, the oxidation-reduction reaction of the metal salt compound on the display-side electrode becomes stable, and the stability in repeated driving increases.

  The necessary performance as a compound that reacts on the electrode on the side opposite to the display side is that the compound itself has high stability, has a sufficient reaction rate, and has an oxidation potential suitable for the driving voltage of the display element. The compounds represented by the general formula (A) or (B) satisfy the above conditions.

The amount of the compound represented by the general formula (A) or (B) is preferably an amount capable of taking out 1 mC / cm ² or more in terms of electricity.

  Details of the present invention will be described below.

[Basic structure of display element]
In the display element of the present invention, the display portion is provided with one corresponding counter electrode. The electrode 1 which is one of the counter electrodes close to the display unit is provided with a transparent electrode such as an ITO electrode, and the other electrode 2 is provided with a conductive electrode. Between the electrode 1 and the electrode 2, it has an electrolyte containing the compound represented by the general formula (1) according to the present invention and a metal salt compound, and the electrode 2 is represented by the general formula (A) according to the present invention. Or at least one of the compounds represented by the general formula (B) is immobilized and reversibly switches between white display and black display by applying a voltage of both positive and negative polarities between the counter electrodes. be able to.

[Compound represented by the general formula (1)]
In the general formula (1), R ₁ represents an alkyl group, a cycloalkyl group, an alkenyl group, a carbonyl group, a carboxyl group or an aryl group, and R ₂ represents a hydrogen atom or an alkyl group. R ₁ and R ₂ may further have a substituent. The ring represents a 5- to 6-membered ring containing a nitrogen atom.

In the present invention, R ₁ is preferably an alkyl group, and the ring is preferably a piperidine ring or a pyrrolidine ring.

  Although the typical example of a compound represented by General formula (1) based on this invention below is shown, this invention is not limited to these.

[Organic solvent]
The electrolyte according to the present invention is characterized by using an amide compound represented by the above general formula (1) as an organic solvent, but in combination with another organic solvent within a range not impairing the object effect of the present invention. May be. The organic solvent that can be used in combination with the compound represented by the general formula (1) is an organic solvent having a boiling point in the range of 120 to 300 ° C. that can remain in the electrolyte without causing volatilization after the electrolyte is formed. For example, propylene carbonate, ethylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, butylene carbonate, γ-butyl lactone, tetramethyl urea, sulfolane, dimethyl sulfoxide, hexamethyl phosphortriamide, N-methylpropionamide, N, N-dimethylacetamide, N-methylacetamide, N, N dimethylformamide, N-methylformamide, butyronitrile, propionitrile, acetonitrile, acetylacetone, 4-methyl-2-pentanone, 2- Tanol, 1-butanol, 2-propanol, 1-propanol, acetic anhydride, ethyl acetate, ethyl propionate, dimethoxyethane, diethoxyfuran, tetrahydrofuran, ethylene glycol, diethylene glycol, triethylene glycol monobutyl ether, tricresyl phosphate, 2 Examples include ethyl hexyl phosphate, dioctyl phthalate, and dioctyl sebacate.

  As other solvents that 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).

[Metal salt compounds]
The metal salt compound according to the present invention is any compound as long as it contains a metal species that can be dissolved and precipitated by driving the counter electrode on at least one electrode on the counter electrode. There may be. Preferred metal species are silver, bismuth, copper, nickel, iron, chromium, zinc and the like, and particularly preferred are silver and bismuth.

[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.

  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.

[Halogen ion, metal ion concentration ratio]
In the display element of the present invention, the molar concentration of halogen ions or halogen atoms contained in the electrolyte is [X] (mol / kg), and silver contained in the electrolyte or the total silver of the compound containing silver in the chemical structure. When the molar concentration is [Metal] (mol / kg), it is preferable to satisfy the condition defined by the following formula (1).

Formula (1)
0 ≦ [X] / [Metal] ≦ 0.1
The halogen atom as used in the field of this invention means an iodine atom, a chlorine atom, a bromine atom, and a fluorine atom. When [X] / [Metal] is greater than 0.1, X ⁻ → X ₂ is generated during the metal redox reaction, and X ₂ easily cross-oxidizes with the deposited metal to dissolve the deposited metal. Therefore, the molar concentration of halogen atoms is preferably as low as possible relative to the molar concentration of metallic silver. In the present invention, 0 ≦ [X] / [Metal] ≦ 0.001 is more preferable. In the case of adding halogen ions, the halogen species preferably have a total molar concentration of [I] <[Br] <[Cl] <[F] from the viewpoint of improving memory properties.

[White scattered matter]
In the present invention, from the viewpoint of further improving display contrast and white display reflectance, white scatterers are contained, and a porous white scatter layer may be formed by the white scatterers.

  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.

  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, 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 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 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. 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 of the vinyl monomer having a (e.g., sodium methacrylate, Copolymers with ammonium acid, potassium acrylate, etc.) are also used. These binders can be used in combination of two or more.

  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, “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, 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.

  The porous as used in the present invention means that a water mixture of the water-based polymer and the white pigment is applied on an electrode and dried to form a porous white scattering material, and then silver or silver is formed on the scattering material. After applying an electrolyte solution containing the compound contained in the chemical structure, it can be sandwiched between the counter electrodes, giving a potential difference between the counter electrodes, causing a silver dissolution precipitation reaction, and ionic species can move between the electrodes Says the penetration state.

  In the display element of the present invention, it is desirable to carry out a curing reaction of the water-based polymer with a curing agent during or after application and drying of 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 water-based polymer. In addition, it is possible to perform heat treatment and humidity adjustment during the curing reaction in order to increase the film strength.

[Compound represented by formula (A) or (B)]
The display element of the present invention is characterized in that the compound represented by the general formula (A) or the compound represented by the general formula (B) is immobilized on at least one counter electrode.

  In the present invention, the method of immobilizing the compound represented by the general formula (A) or the compound represented by the general formula (B) according to the present invention on the counter electrode is represented by the general formula (A). Or a compound and a polymer binder represented by the general formula (B) and a binder and a paste liquid, and a method of applying the paste liquid on the electrode by a printing method or a blade method or a general formula (A) A compound represented by the general formula (A), a method of introducing an adsorptive group that chemically adsorbs to the electrode surface or a compound represented by the general formula (B), or a compound represented by the general formula (B) The method of polymerizing a compound and forming a thin film on the electrode surface is mentioned.

  Hereinafter, the details of the compound represented by formula (A) or (B) according to the present invention will be described.

In the general formula (A) or the general formula (B) according to the present invention, Ra ₁ , Ra ₂ , Rb ₁ , Rb ₂ may each independently have a substituent, an aromatic group, an aromatic heterocyclic ring Represents an aliphatic group. Ra ₁ and Ra ₂ , Rb ₁ and Rb ₂ may be connected to each other to form a cyclic structure.

  Examples of the aromatic hydrocarbon group include a phenyl group and a naphthyl group. Examples of the aromatic heterocyclic group include a pyridyl group, a thiazolyl group, an oxazolyl group, an imidazolyl group, a furyl group, a pyrrolyl group, a pyrazinyl group, and a pyrimidinyl group. Group, pyridazinyl group, selenazolyl group, sulfolanyl group, piperidinyl group, pyrazolyl group, tetrazolyl group, morpholino group and the like. The aliphatic hydrocarbon group includes a chain and a cyclic group, and the chain includes a linear group and a branched group. Such aliphatic hydrocarbon groups include methyl, ethyl, vinyl, propyl, isopropyl, propenyl, butyl, iso-butyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, iso-hexyl, cyclohexyl, cyclohexenyl, Examples include octyl, iso-octyl, cyclooctyl, 2,3-dimethyl-2-butyl and the like.

  These substituents may further have a substituent. These substituents are not particularly limited, and examples thereof include alkyl groups (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, Tetradecyl group, pentadecyl group etc.), cycloalkyl group (eg cyclopropyl group, cyclopentyl group, cyclohexyl group etc.), alkenyl group (eg vinyl group, allyl group, butenyl group, octenyl group etc.), cycloalkenyl group (eg , 2-cyclopenten-1-yl group, 2-cyclohexen-1-yl group, etc.), alkynyl group (eg, propargyl group, ethynyl group, trimethylsilylethynyl group, etc.), aryl group (eg, phenyl group, naphthyl group, p) -Tolyl group, m-chlorophenyl group, o-hexadecanoyl Minophenyl group, etc.), heterocyclic group (for example, pyridyl group, thiazolyl group, oxazolyl group, imidazolyl group, furyl group, pyrrolyl group, pyrazinyl group, pyrimidinyl group, pyridazinyl group, selenazolyl group, sulfolanyl group, piperidinyl group, pyrazolyl group, Tetrazolyl group, morpholino group, etc.), heterocyclic oxy group (for example, 1-phenyltetrazol-5-oxy group, 2-tetrahydropyranyloxy group, pyridyloxy group, thiazolyloxy group, oxazolyloxy group, imidazolyloxy group, etc.) ), Halogen atoms (for example, chlorine atom, bromine atom, iodine atom, fluorine atom, etc.), alkoxy groups (for example, methoxy group, ethoxy group, propyloxy group, tert-butoxy group, pentyloxy group, hexyloxy group, octyl) Oxy group, dodecyl Xy group etc.), cycloalkoxy group (eg cyclopentyloxy group, cyclohexyloxy group etc.), aryloxy group (eg phenoxy group, 2-naphthyloxy group, 2-methylphenoxy group, 4-tert-butylphenoxy group, 3-nitrophenoxy group, 2-tetradecanoylaminophenoxy group, etc.), alkylthio group (eg, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, , Cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, 1-naphthylthio group, etc.), heterocyclic thio group (eg, pyridylthio group, thiazolylthio group, oxazolylthio group, imidazolylthio group, furylthio group) , Pyrrolylthio group, etc.), alkoxycarbonyl group (eg, methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxy) Carbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenyl) Aminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, morpholinosulfonyl group, pyrrolidinosulfonyl group, etc.), urea Group (for example, methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group, etc.), acyl group (for example, Acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group ( For example, formyloxy group, acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxyphenylcarbonyloxy group, ethylcarbonyloxy group Butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), acylamino group (for example, acetylamino group, benzoylamino group, formylamino group, pivaloylamino group, lauroylamino group, 3, 4, 5-tri-n-octyloxyphenylcarbonylamino group), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octyl) Aminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group Group, morpholinocarbonyl group, piperazinocarbonyl group, etc.), alkanesulfinyl group or arylsulfinyl group (for example, methanesulfinyl group, ethanesulfinyl group, butanesulfinyl group, cyclohexanesulfinyl group, 2-ethylhexanesulfinyl group, dodecane) Sulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkanesulfonyl group or arylsulfonyl group (for example, methanesulfonyl group, ethanesulfonyl group, butanesulfonyl group, cyclohexanesulfonyl group, 2-ethylhexanesulfonyl) Group, dodecanesulfonyl group, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, methylamino) , Ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, N-methylanilino group, diphenylamino group, naphthylamino group, 2-pyridylamino group, etc.) Silyloxy group (for example, trimethylsilyloxy group, tert-butyldimethylsilyloxy group, etc.), aminocarbonyloxy group (for example, N, N-dimethylcarbamoyloxy group, N, N-diethylcarbamoyloxy group, morpholinocarbonyloxy group, N N-di-n-octylaminocarbonyloxy group, Nn-octylcarbamoyloxy group, etc.), alkoxycarbonyloxy groups (for example, methoxycarbonyloxy group, ethoxycarbonyloxy group, tert-butoxycarbo group) Ruoxy group, n-octylcarbonyloxy group, etc.), aryloxycarbonyloxy group (for example, phenoxycarbonyloxy group, p-methoxyphenoxycarbonyloxy group, pn-hexadecyloxyphenoxycarbonyloxy group, etc.), alkoxycarbonylamino Groups (for example, methoxycarbonylamino group, ethoxycarbonylamino group, tert-butoxycarbonylamino group, n-octadecyloxycarbonylamino group, N-methyl-methoxycarbonylamino group, etc.), aryloxycarbonylamino groups (for example, phenoxycarbonyl) Amino group, p-chlorophenoxycarbonylamino group, mn-octyloxyphenoxycarbonylamino group, etc.), sulfamoylamino group (for example, sulfamoylamino group, N , N-dimethylaminosulfonylamino group, Nn-octylaminosulfonylamino group, etc.), mercapto group, arylazo group (eg, phenylazo group, naphthylazo group, p-chlorophenylazo group, etc.), heterocyclic azo group (eg, Pyridylazo group, thiazolylazo group, oxazolylazo group, imidazolylazo group, furylazo group, pyrrolylazo group, 5-ethylthio-1,3,4-thiadiazol-2-ylazo group, etc.), imino group (for example, N-succinimido-1-yl) Group, N-phthalimido-1-yl group, etc.), phosphino group (eg dimethylphosphino group, diphenylphosphino group, methylphenoxyphosphino group etc.), phosphinyl group (eg phosphinyl group, dioctyloxyphosphinyl group) , Diethoxyphosphinyl group, etc.) Finyloxy group (for example, diphenoxyphosphinyloxy group, dioctyloxyphosphinyloxy group, etc.), phosphinylamino group (for example, dimethoxyphosphinylamino group, dimethylaminophosphinylamino group, etc.), silyl group (For example, trimethylsilyl group, tert-butyldimethylsilyl group, phenyldimethylsilyl group, etc.), cyano group, nitro group, hydroxyl group, sulfo group, carboxyl group and the like can be mentioned.

  The compound represented by the general formula (A) or the general formula (B) may be a multimer such as a dimer or trimer linked by these substituents, or may be a polymer. Good.

In the general formulas (A) and (B), Ra ₁ , Ra ₂ , Rb ₁ and Rb ₂ are preferably an aromatic hydrocarbon group or an aromatic heterocyclic group, and further an aromatic group substituted with an electron-withdrawing group. An aromatic hydrocarbon group or an electron-deficient aromatic heterocyclic group is preferable, and an aromatic hydrocarbon group substituted with an aromatic hydrocarbon group or an electron-withdrawing group is particularly preferable. The electron withdrawing group is an electron withdrawing group having a Hammett's substituent constant σp value of 0 or more and 1.0 or less. Preferably, it is an electron withdrawing group having a σp value of 0.2 or more and 0.75 or less. Hammett's rule was found in 1935 by L. L. in order to quantitatively discuss the effect of substituents on the reaction or equilibrium of benzene derivatives. P. A rule of thumb proposed by Hammett, which is widely accepted today. Substituent constants determined by Hammett's rule include a σp value and a σm value, and these values are described in many general books. A. Dean "Lange's Handbook of
Chemistry "12th edition, 1979 (McGraw-Hill) and" Chemical domain special issue ", 122, 96-103, 1979 (Nanedo). However, it does not mean that the values known in the literature described in these documents are limited to only certain substituents, and even if the values are unknown, as long as they are included in the range when measured based on Hammett's rule Of course included.

  Specific examples of the electron withdrawing group having a σp value of 0.20 or more include acyl group, acyloxy group, carbamoyl group, alkoxycarbonyl group, aryloxycarbonyl group, cyano group, nitro group, dialkylphosphono group, diarylphosphono group Group, diarylphosphinyl group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfonyloxy group, acylthio group, sulfamoyl group, thiocyanate group, thiocarbonyl group, halogenated alkyl group, halogenated alkoxy group A halogenated aryloxy group, a halogenated alkylamino group, a halogenated alkylthio group, an aryl group substituted with another electron-withdrawing group having a σp value of 0.20 or more, a heterocyclic group, a halogen atom, an azo group, or The selenocyanate group It is.

  The electron-deficient aromatic heterocyclic group is preferably a group derived from a nitrogen-containing 6-membered ring such as a pyridine ring, a pyrazine ring, a pyrimidine ring, or a pyridazine ring.

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

  Specific examples of the compound represented by formula (B) are shown below, but the present invention is not limited to these exemplified compounds.

[Compound represented by general formula (2) or general formula (3)]
In the display element of the present invention, the electrolyte preferably contains at least one selected from the compounds represented by the general formulas (2) and (3).

In the general formula (2), R ⁵ and R ⁶ each represent a substituted or unsubstituted hydrocarbon group, which includes an aromatic straight chain group or a branched group. Further, these hydrocarbon groups may contain one or more nitrogen atoms, oxygen atoms, phosphorus atoms, sulfur atoms, and halogen atoms. However, when a ring containing an S atom is formed, an aromatic group is not taken.

  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.

  Generally, in order to cause dissolution and precipitation of silver, it is necessary to solubilize silver in an electrolyte. For example, coexisting with a compound containing a chemical structural species that interacts with silver, such as a coordinate bond with silver and a weak covalent bond with silver, to make silver or a compound containing silver a solubilized product It is common to use a means for conversion. As the chemical structural species, halogen atoms, mercapto groups, carboxyl groups, imino groups and the like are known, but in the present invention, the thioether group is also useful as a silver solvent and has little influence on the coexisting compound, It is characterized by high solubility in solvents.

  Hereinafter, although the specific example of a compound represented by General formula (2) which concerns on this invention is shown, in this invention, it is not limited only to these illustrated compounds.

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

  Among the above-exemplified compounds, Exemplified Compound 2-3 is particularly preferable from the viewpoint that the object and effects of the present invention can be exhibited.

  Next, the compound represented by formula (3) according to the present invention will be described.

In the general formula (3), M represents a hydrogen atom, a metal atom or quaternary ammonium. Z represents a nitrogen-containing heterocyclic ring excluding imidazole rings. n represents an integer of 0 to 5, and R ⁷ 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 aryloxy group 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, aryl Represents an oxycarbonyl 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, each R ⁷ is They may be the same or different, and may be linked together to form a condensed ring.

Examples of the metal atom represented by M in the general formula (3) 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 and the} like It is done.

  Examples of the nitrogen-containing heterocyclic ring represented by Z in the general formula (3) 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, and a benzimidazole ring. Benzothiazole ring, benzoselenazole ring, naphthoxazole ring and the like.

Examples of the halogen atom represented by R ⁷ in the general formula (3) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group include methyl, ethyl, propyl, i- Examples include propyl, butyl, t-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, octyl, dodecyl, hydroxyethyl, methoxyethyl, trifluoromethyl, benzyl, etc. Examples of the aryl group include phenyl, naphthyl and the like. Examples of the alkylcarbonamide group include acetylamino, propionylamino, butyroylamino and the like. Examples of the arylcarbonamide group include benzoylamino and the like. Examples of the sulfonamide group include methanesulfonyl. Minosulfonyl, ethanesulfonylamino group and the like, arylsulfonamide groups include, for example, benzenesulfonylamino group, toluenesulfonylamino group and the like, and aryloxy groups include, for example, phenoxy and the like, alkylthio Examples of the group include each group such as methylthio, ethylthio, and butylthio. Examples of the arylthio group include phenylthio group and tolylthio group. Examples of the alkylcarbamoyl group include methylcarbamoyl, dimethylcarbamoyl, Examples include ethyl carbamoyl, diethyl carbamoyl, dibutyl carbamoyl, piperidyl carbamoyl, morpholyl carbamoyl and the like, and aryl carbamoyl groups include, for example, phenyl carbamoyl, methyl phenyl carbamoyl Examples include groups such as vamoyl, ethylphenylcarbamoyl, and benzylphenylcarbamoyl. Examples of the alkylsulfamoyl group include methylsulfamoyl, dimethylsulfamoyl, ethylsulfamoyl, diethylsulfamoyl, and dibutylsulfamoyl. Examples of each group include moyl, piperidylsulfamoyl, morpholylsulfamoyl, and arylsulfamoyl groups include, for example, phenylsulfamoyl, methylphenylsulfamoyl, ethylphenylsulfamoyl, benzylphenylsulfamoyl. Examples of the alkylsulfonyl group include a methanesulfonyl group and an ethanesulfonyl group. Examples of the arylsulfonyl group include phenylsulfonyl and 4-chlorophenylsulfonyl. Examples of each group include p-toluenesulfonyl and the like. Examples of the alkoxycarbonyl group include groups such as methoxycarbonyl, ethoxycarbonyl and butoxycarbonyl. Examples of the aryloxycarbonyl group include phenoxycarbonyl and the like. Examples of the alkylcarbonyl group include acetyl, propionyl, butyroyl, and the like. Examples of the arylcarbonyl group include a benzoyl group and an alkylbenzoyl group. Examples of the acyloxy group include acetyloxy. , Propionyloxy, butyroyloxy and the like, and examples of the heterocyclic group include oxazole ring, thiazole ring, triazole ring, selenazole ring, tetrazole ring, oxadiazole ring, thiadiazole ring, thiazol ring, and the like. Down ring, a triazine ring, a benzoxazole ring, benzothiazole ring, an indolenine ring, benzimidazole benzoselenazole ring, naphthothiazole ring, triazaindolizine ring, diaza indolizine ring, tetraazacyclododecane indolizine ring group, and the like. These substituents further include those having a substituent.

  Next, although the preferable specific example of a compound represented by General formula (3) is shown, this invention is not limited to these compounds.

  Among the above-exemplified compounds, Exemplified Compounds 3-12, 3-18, and 3-20 are particularly preferable from the viewpoint that the object and effects of the present invention can be exhibited.

〔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”).
Etc.

[Ionic liquid]
An ionic liquid can be applied to the display element of the present invention. 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, more preferably an ammonium cation, an imidazolium cation, a pyridinium cation, a sulfonium cation, and a phosphonium cation.

The above-mentioned 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 each other hydrogen, saturated or unsaturated carbon, An alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 11 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). groups ammonium is selected from the group consisting of which may have a substituent] and / or phosphonium ^{_{ion, R 1 R 2 N + =}} CR 3 - ^{_{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 represents an alkylene or phenylene group having 1 to 6 carbon atoms, and these groups are substituted) A quaternary ammonium and / or phosphonium ion selected from the group consisting of (which may have a group), an atom selected from nitrogen, sulfur and phosphorus atoms represented by the following general formula: An ammonium ion, a sulfonium ion, a phosphonium ion, or the like derived from a nitrogen-containing, sulfur-containing, and phosphorus-containing heterocyclic ring containing three atoms can be given.

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 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, decyl, a cycloalkyl group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, unsubstituted or halogen atom (F, Cl, Br, I), Hydroxyl group, lower alkoxy group (methoxy, ethoxy, propoxy, butoxy), carboxyl group, acetyl group, propanoyl group, thiol group, lower alkylthio group (methylthio, ethylthio, propylthio, butylthio), amino group, lower alkylamino group, di-lower Substitution such as alkylamino group An aryl group such as phenyl, naphthyl, toluyl and xylyl having 1 to 3 groups, and an aralkyl group such as benzyl can be exemplified. Specific examples of R ₅ include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl groups, and R ₆ represents methylene. 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.

The counter anion represented by A ⁻ in the formula includes hexafluorophosphate, hexafluoroantimonate, hexafluoroarsenate, fluorosulfonate, tetrafluoroborate, nitrate, alkylsulfonate. 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 of the present invention is not limited to a solution electrolyte composed of a solvent or an ionic liquid, but also a high-viscosity electrolyte or gel electrolyte (hereinafter referred to as a gel) containing a solid electrolyte or a polymer compound substantially free of a solvent. Electrolyte).

(Electronic insulation layer)
In the display element of the present invention, an electrical insulating layer can be provided.

  The electronic insulating layer applicable to the present invention may be a layer having both ionic conductivity and electronic insulating properties. For example, a solid electrolyte membrane in which a polymer or salt having a polar group is formed into a film, electronic insulating properties And a porous solid body having a low relative dielectric constant, such as a silicon-containing compound, and the like.

  As a method for forming a porous film, a sintering method (fusion method) (using fine pores formed between particles by adding polymer fine particles or inorganic particles to a binder or the like and partially fusing them), extraction method (After forming a constituent layer with a solvent-soluble organic substance or inorganic substance and a binder that does not dissolve in the solvent, the organic substance or inorganic substance is dissolved in the solvent to obtain pores), heating or degassing the polymer Well-known formation such as foaming method for foaming, phase change method for phase separation of polymer mixture by operating good solvent and poor solvent, radiation irradiation method for forming pores by radiating various radiation The method can be used. Specifically, JP-A-10-30181, JP-A-2003-107626, JP-B-7-95403, JP-A-2635715, JP-A-2894523, JP-A-2987474, JP-A-3066426, and JP-A-3464513. No. 3,483,464, No. 3535942, No. 30622203, and the like.

[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 1006-7 XIII
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
〔substrate〕
Examples of the substrate that can be used in the present invention include polyolefins such as polyethylene and polypropylene, polycarbonates, cellulose acetate, polyethylene terephthalate, polyethylene dinaphthalene dicarboxylate, polyethylene naphthalates, polyvinyl chloride, polyimide, and polyvinyl acetal. Synthetic plastic films such as polystyrene can also be preferably used. Syndiotactic polystyrenes are also preferred. These can be obtained, for example, by the methods described in JP-A Nos. 62-117708, 1-46912 and 1-178505. Further, a metal substrate such as stainless steel, a paper support such as baryta paper and resin coated paper, and a support provided with a reflective layer on the plastic film, supported by JP-A-62-253195 (pages 29-31) The thing described as a body is mentioned. RDNo. 17643, page 28, ibid. No. 18716, page 647, right column to page 648, left column, and No. 307105, page 879 can also be preferably used. As these supports, those having resistance to curling due to heat treatment of Tg or less as in US Pat. No. 4,141,735 can be used. Further, the surface of these supports may be subjected to surface treatment for the purpose of improving the adhesion between the support and other constituent layers. In the present invention, glow discharge treatment, ultraviolet irradiation treatment, corona treatment, and flame treatment can be used as the surface treatment. Furthermore, the support body described in pages 44 to 149 of publicly known technology No. 5 (issued by Aztec Co., Ltd. on March 22, 1991) can also be used. Furthermore, RDNo. 308119, page 1009, Product Licensing Index, Volume 92, P108, “Supports”, and the like. In addition, a glass substrate or an epoxy resin kneaded with glass can be used.

〔electrode〕
In the display element of the present invention, it is preferable that at least one of the counter electrodes is a metal electrode. 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. The metal electrode is preferably a metal having a work function close to the redox potential of silver in the electrolyte. Above all, silver or a silver electrode having a silver content of 80% or more is advantageous for maintaining the reduced state of silver. Excellent in preventing dirt. 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.

  In the display element of the present invention, it is preferable that at least one of the counter electrodes is 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 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.

[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.

Example 1
<< Production of display element >>
(Preparation of electrolyte)
(Preparation of electrolyte 1)
In 2.5 g of dimethyl sulfoxide, 0.1 g of bismuth chloride, 0.1 g of lithium bromide, and 0.025 g of tetrabutylammonium perchlorate were dissolved to obtain an electrolytic solution 1.

(Preparation of electrolyte 2)
In 2.5 g of compound (1-40), 0.1 g of bismuth chloride, 0.1 g of lithium bromide, and 0.025 g of tetrabutylammonium perchlorate were dissolved to obtain an electrolytic solution 2.

(Preparation of electrolyte 3)
In 2.5 g of dimethyl sulfoxide, 0.1 g of silver p-toluenesulfonate and 0.025 g of tetrabutylammonium perchlorate were dissolved to obtain an electrolytic solution 3.

(Preparation of electrolyte 4)
In 2.5 g of the compound (1-40), 0.1 g of silver p-toluenesulfonate and 0.025 g of tetrabutylammonium perchlorate were dissolved to obtain an electrolytic solution 4.

(Preparation of electrolyte 5)
In 2.5 g of the exemplified compound (1-40), 0.1 g of silver p-toluenesulfonate, 0.2 g of the compound (3-12), and spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate 0.025 g was dissolved to obtain an electrolytic solution 5.

(Preparation of electrolyte 6)
In 2.5 g of Exemplified Compound (1-40), 0.1 g of silver p-toluenesulfonate, 0.2 g of Compound (2-3), and spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate 0.025 g was dissolved to obtain an electrolytic solution 6.

(Preparation of electrolyte solution 7)
In 2.5 g of the exemplified compound (1-47), 0.1 g of silver p-toluenesulfonate, 0.2 g of the compound (3-12) and spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate 0.025 g was dissolved to obtain an electrolyte solution 7.

(Preparation of electrolyte 8)
In 2.5 g of Exemplified Compound (1-6), 0.1 g of silver p-toluenesulfonate, 0.2 g of Compound (3-12), and spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate 0.025 g was dissolved to obtain an electrolyte solution 8.

(Preparation of electrolyte 9)
In 2.5 g of the exemplified compound (1-43), 0.1 g of silver p-toluenesulfonate, 0.2 g of the compound (3-12), and spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate 0.025 g was dissolved to obtain an electrolyte solution 9.

[Production of electrodes]
(Production of electrode 1)
An ITO (Indium Tin Oxide) film having a pitch of 145 μm and an electrode width of 130 μm is formed on a glass substrate having a thickness of 1.5 mm and 2 cm × 4 cm according to a known method, and a transparent electrode (electrode 1) is formed. Obtained.

(Preparation of electrode 2)
A nickel electrode having an electrode thickness of 0.1 μm, a pitch of 145 μm, and an electrode interval of 130 μm is formed on a glass substrate having a thickness of 1.5 mm and a size of 2 cm × 4 cm by using a known method. And a gold-nickel electrode (electrode 2) having a depth of 0.05 μm replaced with gold from the electrode surface was obtained.

(Preparation of electrode 3)
600 mg of carbon powder (conductivity imparting agent) and 100 mg of polyvinylidene fluoride (binder) were measured and mixed. 4 ml of acetylacetone was added here, and it stirred until it became a slurry form. The obtained slurry liquid was applied on the electrode 2 with a doctor blade so that the film thickness after drying was 0.5 μm, and then dried at 80 ° C. for 3 minutes to obtain an electrode 3.

(Preparation of electrode 4)
300 mg of exemplary compound (A-29), 600 mg of carbon powder (conductivity imparting agent), and 100 mg of polyvinylidene fluoride (binder) were weighed and mixed. 4 ml of acetylacetone was added here, and it stirred until it became a slurry form. The obtained slurry-like liquid was applied on the electrode 2 with a doctor blade so that the film thickness after drying was 0.5 μm, and then dried at 80 ° C. for 3 minutes to obtain an electrode 4.

(Preparation of electrode 5)
300 mg of the exemplary compound (A-69), 600 mg of carbon powder (conductivity imparting agent), and 100 mg of polyvinylidene fluoride (binder) were weighed and mixed. 4 ml of acetylacetone was added here, and it stirred until it became a slurry form. The obtained slurry-like liquid was applied on the electrode 2 with a doctor blade so that the film thickness after drying was 0.5 μm, and then dried at 80 ° C. for 3 minutes to obtain an electrode 5.

(Preparation of electrode 6)
300 mg of exemplary compound (A-24), 600 mg of carbon powder (conductivity imparting agent), and 100 mg of polyvinylidene fluoride (binder) were weighed and mixed. 4 ml of acetylacetone was added here, and it stirred until it became a slurry form. The obtained slurry-like liquid was applied on the electrode 2 with a doctor blade so that the film thickness after drying was 0.5 μm, and then dried at 80 ° C. for 3 minutes to obtain an electrode 6.

(Preparation of electrode 7)
300 mg of exemplary compound (B-25), 600 mg of carbon powder (conductivity imparting agent) and 100 mg of polyvinylidene fluoride (binder) were weighed and mixed. 4 ml of acetylacetone was added here, and it stirred until it became a slurry form. The obtained slurry-like liquid was applied on the electrode 2 with a doctor blade so that the film thickness after drying was 0.5 μm, and then dried at 80 ° C. for 3 minutes to obtain an electrode 7.

(Preparation of electrode 8)
300 mg of the exemplary compound (B-24), 600 mg of carbon powder (conductivity imparting agent), and 100 mg of polyvinylidene fluoride (binder) were weighed and mixed. 4 ml of acetylacetone was added here, and it stirred until it became a slurry form. The obtained slurry liquid was applied on the electrode 2 with a doctor blade so that the film thickness after drying was 0.5 μm, and then dried at 80 ° C. for 3 minutes to obtain an electrode 8.

(Preparation of electrode 9)
300 mg of exemplary compound (A-1), 600 mg of carbon powder (conductivity imparting agent), and 100 mg of polyvinylidene fluoride (binder) were weighed and mixed. 4 ml of acetylacetone was added here, and it stirred until it became a slurry form. The obtained slurry-like liquid was applied on the electrode 2 with a doctor blade so that the film thickness after drying was 0.5 μm, and then dried at 80 ° C. for 3 minutes to obtain an electrode 9.

(Production of electrode 10)
300 mg of exemplary compound (B-1), 600 mg of carbon powder (conductivity imparting agent), and 100 mg of polyvinylidene fluoride (binder) were weighed and mixed. 4 ml of acetylacetone was added here, and it stirred until it became a slurry form. The obtained slurry-like liquid was applied onto the electrode 2 with a doctor blade so that the film thickness after drying was 0.5 μm, and then dried at 80 ° C. for 3 minutes to obtain the electrode 10.

[Production of display element]
(Preparation of display element 1: comparative example)
After the periphery of the electrode 3 is edged with an olefin-based sealant containing glass spherical beads having an average particle diameter of 40 μm as a volume fraction of 10%, the striped electrodes are orthogonal to the electrodes 3 and 1 respectively. The cells were bonded together and further heated and pressed to produce an empty cell. The electrolytic solution 1 was vacuum-injected into the empty cell, and the injection port was sealed with an epoxy-based ultraviolet curable resin to produce a display element 1.

(Preparation of display element 2: comparative example)
A display element 2 was produced in the same manner as the display element 1 except that the electrolytic solution 1 was changed to the electrolytic solution 2.

(Preparation of display element 3: comparative example)
A display element 3 was produced in the same manner as the display element 1 except that the electrolytic solution 1 was changed to the electrolytic solution 3.

(Preparation of display element 4: comparative example)
A display element 4 was produced in the same manner as the display element 1 except that the electrolytic solution 1 was changed to the electrolytic solution 4.

(Preparation of display element 5: present invention)
The periphery of the electrode 4 is edged with an olefin-based sealant containing glass spherical beads having an average particle size of 40 μm as a volume fraction of 10%, and then the electrode 4 and the electrode 1 are orthogonal to each other in stripes. Then, the cells were bonded together and further heated and pressed to produce an empty cell. The electrolytic solution 4 was vacuum-injected into the empty cell, and the injection port was sealed with an epoxy-based ultraviolet curable resin to produce a display element 5.

(Preparation of display element 6: present invention)
A display element 6 was produced in the same manner as the display element 5 except that the electrolytic solution 4 was changed to the electrolytic solution 5.

(Preparation of display element 7: present invention)
A display element 7 was produced in the same manner as the display element 5 except that the electrolytic solution 4 was changed to the electrolytic solution 6.

(Preparation of display element 8: present invention)
A display element 8 was produced in the same manner as the display element 6 except that the electrode 4 was changed to the electrode 5.

(Preparation of display element 9: present invention)
A display element 9 was produced in the same manner as the display element 6 except that the electrode 4 was changed to the electrode 6.

(Preparation of Display Element 10: Present Invention)
A display element 10 was produced in the same manner as the display element 6 except that the electrode 4 was changed to the electrode 7.

(Preparation of display element 11: present invention)
A display element 11 was produced in the same manner as the display element 6 except that the electrode 4 was changed to the electrode 8.

(Preparation of display element 12: present invention)
A display element 12 was produced in the same manner as the display element 5 except that the electrolytic solution 4 was changed to the electrolytic solution 7.

(Preparation of display element 13: present invention)
A display element 13 was produced in the same manner as the display element 5 except that the electrolytic solution 4 was changed to the electrolytic solution 8.

(Preparation of display element 14: present invention)
A display element 14 was produced in the same manner as the display element 5 except that the electrolytic solution 4 was changed to the electrolytic solution 9.

(Preparation of display element 15: present invention)
A display element 15 was produced in the same manner as the display element 6 except that the electrode 4 was changed to the electrode 9.

(Preparation of display element 16: present invention)
A display element 16 was produced in the same manner as the display element 6 except that the electrode 4 was changed to the electrode 10.

  Table 1 shows the main structure of each of the manufactured display elements.

<< Evaluation of display element >>
[Evaluation of rewriting speed of black display]
Connect both electrodes of the manufactured display element to both terminals of the constant voltage power supply, control the upper limit of the current value to 10 mA per square centimeter, and apply a constant voltage of -1.5 V to the display side electrode for 1 second. Then, the reflectance at a wavelength of 550 nm was measured with a spectrocolorimeter CM-3700d manufactured by Konica Minolta Sensing Co., Ltd., and the obtained value was defined as R _BK . Here, the smaller the value of R _BK, the faster the rewriting speed for black display.

[Evaluation of rewriting speed of white display]
Connect both electrodes of the display element to both terminals of the constant voltage power supply, and adjust the reflectance on the display side so that the reflectance at a wavelength of 550 nm measured with a spectrocolorimeter CM-3700d manufactured by Konica Minolta Sensing becomes 10%. A voltage of -1.5 V was applied to the electrode for an appropriate time to display in gray. Next, the upper limit of the current value was controlled to 10 mA per square centimeter, and a constant voltage of +1.5 V was applied to the display-side electrode for 0.5 seconds to erase the color from a gray state with a reflectance of 10%. wavelength 550nm reflectance was measured in the same way when the resulting value was defined as R _W. Here, as the value of R _W is large, resulting in fast rewriting speed of the white display.

  Table 1 shows the evaluation results obtained as described above.

  As is apparent 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 faster rewriting speed of black display and white display than the comparative example.

Claims (5)

Between the counter electrodes, an electrolyte containing a compound represented by the following general formula (1) and a metal salt compound and a white scattering material are included, and at least one counter electrode is represented by the following general formula (A). A display element, wherein a compound or a compound represented by the general formula (B) is immobilized, and displays black and white by applying a voltage between the counter electrodes.
[Wherein, R ₁ represents an alkyl group, a cycloalkyl group, an alkenyl group, a carbonyl group, a carboxyl group or an aryl group, and R ₂ represents a hydrogen atom or an alkyl group. R ₁ and R ₂ may further have a substituent. The ring represents a 5-membered ring or 6-membered ring containing a nitrogen atom. ]
[Wherein, Ra ₁ , Ra ₂ , Rb ₁ and Rb ₂ each independently represent an aromatic hydrocarbon group, an aromatic heterocyclic group or an aliphatic hydrocarbon group which may have a substituent. Ra ₁ and Ra ₂ , Rb ₁ and Rb ₂ may be connected to each other to form a cyclic structure. ]   The display element according to claim 1, wherein the metal salt compound is a silver salt compound. The Ra ₁ and Ra ₂ in the general formula (A) and the Rb ₁ and Rb _{2 in} the general formula (B) are each an aromatic hydrocarbon group or an aromatic heterocyclic group. The display element according to item 1 or 2. In the general formula (A), Ra ₁ and Ra ₂ and Rb ₁ and Rb _{2 in} the general formula (B) are each an aromatic hydrocarbon group substituted with an electron-withdrawing group or an electron-deficient aromatic heterocyclic ring. The display element according to any one of claims 1 to 3, wherein the display element is a base. The display element according to any one of claims 1 to 4, wherein the electrolyte contains a compound represented by the following general formula (2) or general formula (3).
General formula (2)
R ⁵ -S-R ⁶
[Wherein, R ⁵ and R ⁶ each represents a substituted or unsubstituted hydrocarbon group. However, when a ring containing an S atom is formed, an aromatic group is not taken. ]
[Wherein, M represents a hydrogen atom, a metal atom or quaternary ammonium. Z represents a nitrogen-containing heterocyclic ring. n represents an integer of 0 to 5, and R ⁷ 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 aryloxy group 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, aryl Represents an oxycarbonyl 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, each R ⁷ May be the same or different and may be linked to each other to form a condensed ring. ]