JP2010243563A - Modified electrode and electrochemical display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode with little characteristic change by repetitive drive and to provide an electrochemical display element can be driven with a simple member construction and at a low voltage, has little characteristic change by the repetitive drive and has a high rewrite speed. <P>SOLUTION: A modified electrode has an electrode material on a substrate and includes a redox polymer compound fixed through chemical bond on the electrode material. The redox polymer compound is the copolymer of two or more of redox monomers. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a novel modified electrode on which a redox compound is immobilized and an electrochemical display element using the novel modified electrode.

  In general, the surface of a metal, carbon, or semiconductor, which is an electrode material, is modified with a functional compound, and an electrode imparted with properties and functions not found in a base metal is called a modified electrode. In particular, as a functional compound, a modified electrode modified with a redox compound is used for an electrode for a display element such as an electrochromic display element, an electrode for various secondary batteries such as a radical battery, various sensors such as a biosensor, and asymmetric electrolysis. As an electrode, it is used in a wide range of applications.

  These modified electrodes are required to withstand stable and long-term use, and advanced modification techniques are required. Examples of the method for immobilizing a functional substance on an electrode include a direct chemical bonding method, an indirect chemical bonding method, and an adsorption method. Although direct or indirect chemical bonding methods are superior from the practical aspects such as chemical stability and durability, sufficient durability has not yet been obtained.

  The electrode modification layer is classified into a monomolecular layer or less (for example, an island shape), a monomolecular layer, and a multimolecular layer. For molecular recognition such as various sensors, the function can be expressed by modification of a single molecule to several molecular layers, but functional substances are highly used as electrodes for display elements, electrodes for secondary batteries, and electrodes for electrolytic synthesis. It is necessary to modify the density. However, the modified electrodes modified with these multi-molecular layers were greatly deteriorated by repeated driving.

  On the other hand, the modified electrode of the present invention can be applied to an electrode for a reflective display such as electronic paper. Among them, an electrochromic display element (hereinafter abbreviated as EC method) and an electrodeposition method (hereinafter abbreviated as ED method) utilizing dissolution or precipitation of a metal or a metal salt have attracted attention. The EC method has the advantage of being capable of full-color display at a low voltage of 3V or less, a simple cell configuration, and excellent white quality. The ED method can also be driven at a low voltage of 3V or less and is a simple cell. There are advantages such as excellent configuration, black-to-white contrast and black quality, and various methods have been disclosed (see, for example, Patent Documents 1 to 5).

  There has been a problem that the characteristics of the electrode change when it is repeatedly driven as a problem of the ED method or EC method. For example, in an EC display element, a technique of fixing a ferrocene polymer to a counter electrode by physical adsorption is known (for example, Patent Document 6). However, physical adsorption may dissolve in the electrolyte, and the durability when repeatedly driven is not sufficient. In addition, although the ED method is excellent in terms of white contrast and black quality, since the metal or metal salt dissolves and precipitates not only on the display electrode side but also on the counter electrode side, the electrode is more likely to deteriorate than the EC method. There has been a demand for further durability improvement technology. In addition, when a polymer having a small degree of freedom of redox group is immobilized, the detailed reason is unknown when the redox reaction is repeated, but the redox ability is extremely lowered. Therefore, the durability when it is repeatedly driven is not sufficient.

International Publication No. 04/068231 Pamphlet International Publication No. 04/066733 Pamphlet U.S. Pat. No. 4,240,716 Japanese Patent No. 3428603 JP 2007-72368 A JP 2008-111941 A

  The present invention has been made in view of the above problems, and an object thereof is to provide a modified electrode with little characteristic change in repeated driving, and can be driven with a simple member configuration, low voltage, and repeatedly driven. It is an object of the present invention to provide an electrochemical display element with a small change in characteristics and a high rewrite speed.

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

  1. A modified electrode comprising a redox polymer compound having an electrode material on a substrate and being immobilized on the electrode material through a chemical bond, wherein the redox polymer compound comprises two or more redox monomers. A modified electrode, characterized in that it is a copolymer.

  2. 2. The modified electrode as described in 1 above, wherein at least one of the redox monomers has a spacer between a redox group and a reactive group capable of causing polymerization.

  3. 3. The modified electrode as described in 1 or 2 above, wherein the redox monomer is a metallocene monomer.

  4). 4. The modified electrode as described in 3 above, wherein the metallocene monomer is a ferrocene derivative.

5). The redox polymer compound is —COOH, —P═O (OH) ₂ , —OP═O (OH) ₂ , —NCO or —Si (R ₁ ) _{3 -n} (OR ₂ ) _n (R ₁ , R ₂ 5 represents an alkyl group, and n represents an integer of 1 to 3. The modified electrode according to any one of 1 to 4 above, which has a group.

  6). 6. An electrochemical display element, wherein the modified electrode according to any one of 1 to 5 is used for at least one of a pair of opposing electrodes.

  7). 7. The electrochemical display element as described in 6 above, wherein white and black are displayed using color development by electrochemical reduction precipitation of metal salt and decoloration by electrochemical oxidation dissolution.

  According to the present invention, it is possible to provide a modified electrode that has a simple member configuration, can be driven at a low voltage, and has little characteristic change in repeated driving. In addition, an electrochemical display element that has a simple member configuration, can be driven at a low voltage, has little characteristic change due to repeated driving, and has a high rewriting speed can be provided.

  As a result of intensive studies in view of the above problems, the present inventor has obtained a modified electrode having an electrode material on a substrate and a redox polymer compound immobilized on the electrode material through a chemical bond. In addition, the modified electrode in which the redox polymer compound is a copolymer of two or more redox monomers can be used to obtain a modified electrode that can be driven with a simple member configuration, low voltage, and has few characteristic changes in repeated driving. The headline, the present invention has been reached.

  Such an effect is exhibited because the redox polymer compound has a reactive group in the molecule, and therefore has excellent adhesion to the electrode and excellent stability of repeated driving. In addition, since the redox polymer compound is a compound in which two or more types of redox monomers having different structures are copolymerized, the degree of freedom of the redox part of the redox polymer compound is increased, and the mobility of ions in the electrolyte can be maintained, which is durable. It is presumed that the performance has further improved.

  Hereinafter, the present invention will be described in detail.

[Redox polymer compound]
In electrochemical display elements, it is necessary to coat the counter electrode in order to prevent dissolution or precipitation of the metal or metal salt on the counter electrode, and the polymer can be formed with a controlled film thickness. The amount of electricity can be set.

  The modified electrode of the present invention is characterized in that the redox polymer compound immobilized on the electrode material via a chemical bond is a copolymer of two or more redox monomers. Hereinafter, this redox polymer compound which is a copolymer of redox monomers is also referred to as a redox polymer compound of the present invention.

  The redox polymer compound of the present invention is synthesized by a polymerization reaction of a redox monomer. The redox monomer is preferably composed of a redox group and a reactive group capable of causing polymerization, and has a spacer therebetween.

  The redox group is not particularly limited as long as it can cause an electrically reversible redox reaction. Of these, a nitroxyl radical group, a quinone group, and a metallocene group are preferable, and a metallocene group is particularly preferable. Furthermore, the metallocene group is preferably a ferrocene derivative.

  Moreover, the redox polymer compound may contain the monomer unit which does not have a redox group other than the said redox monomer. Examples of the monomer body having no redox group include silane compounds, carboxylic acid compounds, and phosphoric acid compounds having a polymerizable group such as an acryl group, a vinyl group, and a styryl group.

The redox polymer compound has a reactive group for chemical bonding with the electrode surface. As reactive groups, —COOH, —P—O (OH) ₂ , —OP═O (OH) ₂ , —NCO and —Si (R ₁ ) _{3 -n} (OR ₂ ) _n (R ₁ , R ₂ are Represents an alkyl group, and n represents an integer of 1 to 3. Among these, —Si (OR ₂ ) ₃ that forms a stronger bond is particularly preferable in improving the stability of repeated driving of the display element.

  In general, examples of the method for supporting the polymer compound on the porous electrode include coating methods such as electrolytic polymerization, electrolytic deposition, dip, spin, and cast, and any method may be used in the present invention.

  When the redox group of the redox polymer compound of the present invention is a metallocene group, a structure represented by the following general formula (1) can be applied.

In the general formula (1), M ₁ and M ₂ represent metal atoms capable of forming a metallocene structure, and may be the same metal atom or different metal atoms. Specific examples include iron, ruthenium, zirconium, titanium and the like, and iron is particularly preferable.

In the formula, R _{1 to} R ₂₄ each independently represents a hydrogen atom or an aliphatic hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic group which may have a substituent.

S _1, S ₂ each represent a spacer, it may or may not have, but preferably has a different spacer lengths by A units and B units. The spacer portion may have a linear structure and may contain a branched structure. Further, it may contain a carbon atom-heteroatom bond other than a carbon-carbon bond, or a heteroatom bond-heteroatom bond.

At least one of R _{1 to} R ₂₄ preferably has the following reactive group as a partial structure. As reactive groups, —COOH, —P—O (OH) ₂ , —OP═O (OH) ₂ , —NCO and —Si (R ₁ ) _{3 -n} (OR ₂ ) _n (R ₁ , R ₂ are Represents an alkyl group, and n represents an integer of 1 to 3.

  In the formula, n and m are degrees of polymerization, and are integers set so that the total molecular weight is 1000 or more. The degree of polymerization is not particularly limited, but if the degree of polymerization is too high, the solubility in a solvent is lowered, which causes a problem in electrode production. For this reason, a molecular weight of 1000 or more and 100000 or less, which has a moderate solubility, is preferable.

  The present invention is characterized in that the structure of the A unit is different from that of the B unit. Preferably, the structure of the redox part is the same and the length of the spacer is different.

(spacer)
The spacer is present between the redox group and the reactive group that can cause polymerization. The reactive group capable of causing polymerization mainly indicates a double bond, a triple bond, an epoxy group, etc., and a part that is not incorporated into the main chain after the polymerization reaction, such as a benzene ring part of a styryl group or an ester part of an acrylic group. Consider it a spacer.

  As long as the spacer has at least a linear structure, the spacer may consist of only a linear structure or may have a branched structure. Or you may have a cyclic structure between a linear structure and a linear structure. Further, it may contain a carbon atom-heteroatom bond other than a carbon-carbon bond, or a heteroatom bond-heteroatom bond. Specific examples of the linear structure containing different atoms other than carbon include an ether bond, an ester bond, an amide bond, a thioether bond, a urea bond, a carbamate bond, and a carbonate bond. From the viewpoint of freedom, it is preferable not to include a highly rigid bond such as a double bond or a triple bond.

  Although the specific example of the redox polymer compound which can be used by this invention below is shown, it is not limited to these. n, m, and l represent the degree of polymerization for each composition, and take numbers in the range where the total molecular weight is 1000 or more and 100,000 or less.

(Synthesis of redox polymer compound)
Synthesis of Exemplified Compound P-13 2 ml of THF deaerated in a 10 ml eggplant flask, 0.53 g of vinyl ferrocene, 1.0 g of ferrocene carboxyethoxyethyl acrylate, 117 mg of acrylate-3- (trimethoxysilyl) propyl and 0.041 g of AIBN in this order In addition, the mixture was refluxed with stirring at 75 ° C. for 8 hours under a nitrogen atmosphere. After completion of the reaction, 2 ml of THF was added, and the reaction solution was added dropwise to 60 ml of methanol to obtain 1.3 g of orange solid P-13.

  The structure of Exemplified Compound P-13 was confirmed by a nuclear magnetic resonance spectrum. As a result of measuring the molecular weight using a gel permeation chromatography (Mel permeation chromatography) system, Mn (number average molecular weight) = 6500 and Mw (weight average molecular weight) = 22000.

  Other compounds can be synthesized in the same manner.

(Chemical bond)
The redox polymer compound of the present invention that is bonded and fixed to the electrode material via a chemical bond may be bonded by a modification via a functional group, or may be bonded by a reaction via a spacer molecule having these functional groups. May be.

For example, the following formula (R ¹ O) ₃ Si—R ² —NH
(In the formula, R ¹ and R ² each represent a hydrocarbon group.)
Is reacted with the surface hydroxyl group of the electrode,
A—O—Si (OR ¹ ) ₂ —R ² —NH ₂ (A represents an electrode) bond is formed, and then
R ³ —CO—OH
(In the formula, R ³ represents a metallocene polymer compound.)
A carboxy compound represented by
It is possible to carry out the reaction modification of _{^{A-O-Si (OR 1}} ) 2 -R 2 -NH-CO-R 3. Of course, various things may be considered without being limited to the reaction modification as illustrated.

In the above reaction, R 3 may be reacted with the surface hydroxyl groups with which previously held the silane coupling group as a compound having a ^(redox polymer compound).

[Basic structure of display element]
In the display element of the present invention, a pair of opposed electrodes is provided. A transparent electrode such as an ITO electrode is provided on the electrode 1 which is one of a pair of opposed electrodes close to the display portion, and a conductive electrode is provided on the other electrode 2. Between the electrode 1 and the electrode 2, it has an electrolyte layer containing the organic solvent, the metal salt compound, the redox polymer compound of the present invention represented by the general formula (1), etc. By applying a bipolar voltage, white display and black display can be switched reversibly.

[Electrolyte composition]
(Organic solvent)
An organic solvent may be used in combination with the electrolyte according to the present invention. The organic solvent preferably has a boiling point in the range of 120 to 300 ° C., for example, propylene carbonate, ethylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, butylene carbonate, γ-butyl lactone, sulfolane, dimethyl sulfoxide, butyronitrile. , Propionitrile, acetonitrile, acetylacetone, 4-methyl-2-pentanone, 2-butanol, 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-ethylhexyl phosphate , It can be exemplified dioctyl phthalate, dioctyl sebacate or the like.

(Metal salt compound)
The metal salt compound according to the present invention is a salt containing a metal species that can be dissolved and precipitated by driving the pair of opposed electrodes on at least one electrode on the pair of opposed electrodes. Any compound may be used as long as it is present. 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. It is a generic term, and there are no particular limitations on the state species of the phase 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 the silver salt, a compound that does not have a nitrogen atom having a coordination property with halogen, carboxylic acid, or silver, and for example, silver trifluoromethanesulfonate is preferable.

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

(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 larger than 0.1, X− → X ₂ is generated during the oxidation-reduction reaction of the metal, 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.

(Metal salt solvent compound)
In the present invention, a silver salt solvent can be used to promote dissolution and precipitation of metal salts (particularly silver salts). The silver salt solvent may be any compound as long as it can solubilize silver in the electrolyte. For example, silver or a compound containing silver coexisting with a compound containing a chemical structural species that interacts with silver, such as a coordinate bond with silver or a weak supply bond with silver. It is common to use a means for converting to a solubilizate. 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 because it has a small influence on the coexisting compound and high solubility in a solvent.

  In particular, it is preferable to contain at least one compound represented by the following general formula (G1) or general formula (G2).

(Compound represented by General Formula (G1) or General Formula (G2))
General Formula _{(G1) Rg 11 -S-Rg} 12
(Wherein 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 atoms, halogen atoms are substituted. Rg ₁₁ and Rg ₁₂ may be connected to each other to form a cyclic structure.

(In the formula, 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 substituent. In the case where n is 2 or more, each Rg ₂₁ may be the same or different, and may be linked to each other to form a condensed ring.
In the general formula (G1), Rg ₁₁ and Rg ₁₂ each represent a substituted or unsubstituted hydrocarbon group, which includes an aromatic straight chain group or a branched group. These hydrocarbon groups may contain one or more nitrogen atoms, oxygen atoms, phosphorus atoms, and sulfur atoms, and Rg ₁₁ and Rg ₁₂ may be connected to each other to form a cyclic structure. 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.

  Hereinafter, specific examples of the compound represented by the general formula (G1) according to the present invention will be shown, but the present invention is not limited only 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 ⁻

  Among the above-exemplified compounds, the exemplified compound G1-3 is particularly preferable from the viewpoint that the object and effects of the present invention can be exhibited.

  Next, the compound represented by formula (G2) according to the present invention will be described.

In the general formula (G2), 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, Rg ₂₁ represents a substituent, and when n is 2 or more, each Rg ₂₁ may be the same or different, and may be connected to each other to form a condensed ring. It may be formed.

Examples of the metal atom represented by M in the general formula (G2) 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 heterocycle having Z as a constituent in general formula (G2) 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, and a benzimidazole Ring, benzothiazole ring, benzoselenazole ring, naphthoxazole ring and the like.

The substituents represented by Rg ₂₁ of the general formula (G2), is not particularly limited, include, for example, substituents as described below.

  Hydrogen atom, 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 groups (eg, phenyl, naphthyl, etc.), alkylcarbonamide groups (eg, acetylamino, propionylamino, butyroylamino, etc.), aryl Carboxamide groups (eg, benzoylamino), alkylsulfonamide groups (eg, methanesulfonylamino group, ethanesulfonylamino group, etc.), arylsulfonamide groups (eg, benzenesulfonylamino group, toluenesulfonylamino) Group), alkoxy group, aryloxy group (for example, phenoxy), alkylthio group (for example, methylthio, ethylthio, butylthio, etc.), arylthio group (for example, phenylthio group, tolylthio group, etc.), alkylcarbamoyl group (for example, methylcarbamoyl group) Dimethylcarbamoyl, ethylcarbamoyl, diethylcarbamoyl, dibutylcarbamoyl, piperidylcarbamoyl, morpholylcarbamoyl, etc.), arylcarbamoyl groups (eg, phenylcarbamoyl, methylphenylcarbamoyl, ethylphenylcarbamoyl, benzylphenylcarbamoyl, etc.), carbamoyl groups, alkylsulfurates Famoyl groups (eg methylsulfamoyl, dimethylsulfamoyl, ethylsulfamoyl, diethylsulfamoyl, dibu Sulfamoyl, piperidylsulfamoyl, morpholylsulfamoyl, etc.), arylsulfamoyl groups (eg, phenylsulfamoyl, methylphenylsulfamoyl, ethylphenylsulfamoyl, benzylphenylsulfamoyl, etc.), sulfamoyl groups , A cyano group, an alkylsulfonyl group (eg, methanesulfonyl group, ethanesulfonyl group, etc.), an arylsulfonyl group (eg, phenylsulfonyl, 4-chlorophenylsulfonyl, p-toluenesulfonyl, etc.), an alkoxycarbonyl group (eg, methoxycarbonyl, Ethoxycarbonyl, butoxycarbonyl etc.), aryloxycarbonyl group (eg phenoxycarbonyl etc.), alkylcarbonyl group (eg acetyl, propionyl, butyroyl etc.), a A reelcarbonyl group (for example, benzoyl group, alkylbenzoyl group, etc.), an acyloxy group (for example, acetyloxy, propionyloxy, butyroyloxy, etc.), a carboxyl group, a carbonyl group, a sulfonyl group, an amino group, a hydroxy group, or a 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, tetraazaindolizine ring group, etc.). These substituents further include those having a substituent.

  Next, although the preferable specific example of a compound represented by general formula (G2) is shown, this invention is not limited to these compounds.

  Of the above-exemplified compounds, Exemplified Compounds G2-12 and G2-20 are particularly preferable from the viewpoint that the object and effects of the present invention can be exhibited.

[Supporting electrolyte]
As the supporting electrolyte that can be used in the electrolyte composition 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 is no restriction | limiting in particular as salts, For example, inorganic ion salts, such as an alkali metal salt and alkaline-earth metal salt; Quaternary ammonium salt; Cyclic quaternary ammonium salt; Quaternary phosphonium salt etc. 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 Li salt, Na salt having a counter anion selected from ₆ ⁻ , AsF ₆ ⁻ , CH ₃ COO ⁻ , CH ₃ (C ₆ H ₄ ) SO ₃ ⁻ , and (C ₂ F ₅ SO ₂ ) ₃ C ⁻ 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 ,
Moreover,

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 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.

[White scattered matter]
In the present invention, from the viewpoint of further increasing the display contrast and the white display reflectance, it is preferable to contain a white scattering material, and a porous white scattering layer may be formed and present.

  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. Further, Research Disclosure and those described on pages (71) to (75) of JP-A No. 64-13546, US Pat. No. 4,960,681, No. JP-A No. 62-245260 Or the like, or a homopolymer of vinyl monomers having —COOM or —SO ₃ M (M is a hydrogen atom or an alkali metal), or such vinyl monomers or other vinyl monomers (for example, methacrylic monomers). A copolymer with sodium acid, ammonium methacrylate, potassium acrylate, etc.) is 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, the aqueous polyurethane resin described in JP-A-10-76621 is preferably used.

  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.

[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 gel electrolyte (hereinafter, referred to as a solid electrolyte or a polymer compound containing substantially no solvent). Gel electrolyte) can be used.

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

(Thickener added with electrolyte)
In the electrochemical display device of the present invention, a thickener can be used for the electrolyte. Examples of the thickener include gelatin, gum arabic, poly (vinyl alcohol), hydroxyethyl cellulose, hydroxypropyl cellulose, and cellulose acetate. , Cellulose acetate butyrate, poly (vinyl pyrrolidone), 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 (esters) Urethane), Fe Xyresin, poly (vinylidene chloride), poly (epoxide) s, poly (carbonates), poly (vinyl acetate), cellulose esters, poly (amides), hydrophobic transparent binders such as polyvinyl butyral, cellulose acetate, cellulose Examples include acetate butyrate, polyester, polycarbonate, polyacrylic acid, and polyurethane.

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

  In the electrochemical display device of the present invention, polyethylene glycol having an average polymerization degree of 100 to 500 is preferable as the thickener, and is added in a mass ratio of 5 to 20% with respect to the organic solvent of the electrolyte layer. Is preferred.

〔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, polyether sulfone, 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 pair of opposing electrodes according to the present invention, the electrode located 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.

  As an electrode located on the display side, Indium Tin Oxide (ITO: Indium Tin Oxide), Indium Zinc Oxide (IZO: Indium Zinc Oxide), Fluorine Doped Tin Oxide (FTO), Indium Oxide, Zinc Oxide, etc. An electrode made of a transparent conductive oxide is preferable.

  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 inkjet 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 performing anodization, photoelectrochemical etching, etc. after forming an electrode layer by sputtering method, CVD method, atmospheric pressure plasma method, 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, an arbitrary shape such as an indefinite shape, a needle shape, or 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.

(Porous carbon electrode)
In the present invention, a porous carbon electrode can also be used. Porous carbon electrodes that can be adsorbed and supported include graphite, non-graphitizable carbon, graphitizable carbon, composite carbon, and carbon compounds obtained by doping carbon with boron, nitrogen, phosphorus, etc. Can be mentioned. Examples of the shape of the carbon particles include mesophase microspheres and fibrous graphite. Mesophase spherules are obtained by firing coal tar pitch or the like at 350 to 500 ° C., and further classifying these spherules and graphitizing by high-temperature firing provides a good porous carbon electrode. In addition, fibrous graphite can be obtained from pitch-based, PAN-based, and vapor-grown fibers.

[Modified electrode]
The electrode material may be any conductive material, such as a metal such as Cu, Al, Pt, Ag, Pd, or Au, an oxide semiconductor such as ITO, SnO ₂ , TiO ₂ , or ZnO, or carbon. May be.

  In the present invention, the electrode substrate surface comprising these metals, carbon, and oxide semiconductor may be modified with a compound that can be directly oxidized / reduced, and the metal, oxide semiconductor, or carbon (for example, carbon nanotube, glassy carbon, diamond-like) is modified. A composite electrode in which a nanoporous electrode layer is formed on an electrode substrate after modifying a compound capable of being oxidized and reduced on the surface of conductive fine particles made of carbon, nitrogen-containing carbon, or the like.

When used as an electrode for a display element, it is necessary to modify the compound to be oxidized / reduced with high density, and therefore a composite electrode in which a nanoporous electrode is formed is preferable. The fine particles used in this case are preferably oxide semiconductor fine particles such as ITO and TiO ₂ , and particularly preferably ITO fine particles.

(Auxiliary electrode)
An auxiliary electrode can be attached to at least one of the pair of opposing 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 suitably formed according to the required performance, such as a straight line, a mesh, or a circle. 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.

  Although the line width and line interval of the auxiliary electrode pattern of the present invention may be arbitrary values, it is necessary to increase the line width 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)
In order to form the display side electrode and the counter electrode (auxiliary electrode), a known method can be used. For example, mask deposition may be performed on the substrate by sputtering or the like, or patterning may be performed by photolithography after the entire surface is formed.

  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 coating, known methods such as a dipping method, a spinner method, a spray method, a roll coater method, a flexographic printing method, and a screen printing method can be used.

  Among the ink jet systems, the following electrostatic ink jet can print a highly viscous liquid continuously 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)
In the electrochemical 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 a solution in the nozzle. It is preferable to use a liquid discharge apparatus including a supply means for supplying the liquid and discharge voltage application means for applying a discharge voltage to the solution in the nozzle.

  Furthermore, it is preferable that the solution in the nozzle is formed using a discharge device provided with a convex meniscus forming means for forming a state where the solution rises in a convex shape from the nozzle tip.

  In addition, an operation control unit that controls application of a drive voltage for driving the convex meniscus forming unit and application of a discharge voltage by the discharge voltage application unit is provided, and the operation control unit applies the discharge voltage by the discharge voltage application unit. 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 while performing the above.

  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 is configured to swell the solution by the convex meniscus forming unit and apply the discharge voltage. And a second discharge control unit that performs synchronization with the liquid discharge device, wherein the operation control means is configured to supply the liquid 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 the surface inward.

  By producing an electrode pattern using such an electrostatic ink jet, an electrode having excellent on-demand properties, little waste material, and excellent dimensional accuracy can be advantageously obtained.

(Electronic insulation layer)
In the electrochemical 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 (fusing method) (using fine pores formed between particles by partially fusing polymer fine particles or inorganic particles by adding a binder, etc.), extraction method ( After forming the constituent layer with a solvent-soluble organic or inorganic substance and a binder that does not dissolve in the solvent, the organic or inorganic substance is dissolved with the solvent to obtain pores), and the polymer is heated or degassed Well-known forming methods such as foaming method for foaming, phase change method for phase separation of polymer mixture by operating good solvent and poor solvent, and radiation irradiation method for forming pores by radiating various radiations Can be used. Specifically, Japanese Patent Application Laid-Open Nos. 10-30181, 2003-107626, 7-95403, Japanese Patent Nos. 2635715, 2849523, 29987474, 30664426, and 3464513. No. 3,483,464, No. 3535942, No. 30622203, and the like.

[Other components of electrochemical element]
In the electrochemical 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 region 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.

[Driving method of electrochemical display element]
The driving operation of the electrochemical 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 advantages 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 electrochemical display element of the present invention can be used in the electronic book field, the ID card related field, the public related field, the transportation related field, the broadcasting related field, the settlement related field, the distribution logistics related 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 << Preparation of electrochemical display element >>
(Preparation of electrolyte)
(Preparation of electrolyte 1)
In 2.5 g of γ-butyrolactone, 0.1 g of silver p-toluenesulfonate, 0.2 g of compound (G1-4) and 0.025 g of spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate were dissolved. Electrolyte solution 1 was obtained.

(Preparation of electrolyte 2)
In 2.5 g of γ-butyrolactone, 0.1 g of silver trifluoromethanesulfonate, 0.2 g of the compound (G1-4) and 0.025 g of lithium bis (trifluoromethanesulfonylimide) were dissolved to obtain an electrolytic solution 2.

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

(Preparation of electrode 2)
On the electrode 1, ITO ink X-490CN27 (Sumitomo Metal Mining Co., Ltd., average particle size: 20 nm) and zinc oxide particles (Wako Pure Chemical Industries, Ltd., average particle size: 20 nm) are 15% by mass with respect to the ITO particles. The mixture was stirred and mixed, and the mixture was applied by spin coating. After baking at 180 ° C. and drying, the sample was immersed in dilute nitric acid (diluted nitric acid having a specific gravity of 1.38 10 times), washed and dried to obtain an electrode 2 having a thickness of 0.4 μm.

(Preparation of electrode 3)
Using the electrode 2 and the following H-1, the electrode 3 was obtained by the method described in JP 2008-111941 A, paragraph [0053].

(Preparation of electrode 4)
Mix and stir the ITO ink X-490CN27 (manufactured by Sumitomo Metal Mining Co., Ltd., average particle size: 20 nm) with Jonkrill emulsion PDX7696 (manufactured by BASF, average particle size: 80 nm) at 15% by mass with respect to the ITO particles. , 1 L of a mixed solution (total solid content 20% by mass) was prepared. 100 ml of the following H-2 / THF solution was added to the mixed solution, and the mixture was stirred for 24 hours at 80 ° C., and then the mixed solution was applied to the ITO film on the substrate glass by spin coating. After baking at 180 ° C. and drying, it was immersed in a 1 mol / L sodium hydroxide solution to wash away the emulsion, and then washed and dried to obtain an electrode 4 having a thickness of 0.4 μm.

(Preparation of electrode 5)
Electrode 5 was obtained in the same manner except that H-2 was changed to P-3 (Mn = 8000, Mw = 35600) in preparation of electrode 3.

(Preparation of electrode 6)
Electrode 6 was obtained in the same manner except that H-2 was changed to P-13 (Mn = 6500, Mw = 22000) in preparation of electrode 3.

(Preparation of electrode 7)
Electrode 7 was obtained in the same manner except that H-2 was changed to P-19 (Mn = 9500, Mw = 39600) in preparation of electrode 3.

(Preparation of electrode 8)
Electrode 8 was obtained in the same manner except that H-2 was changed to P-43 (Mn = 7000, Mw = 26000) in the production of electrode 3.

(Preparation of electrode 9)
Electrode 9 was obtained in the same manner except that H-2 was changed to P-48 (Mn = 10000, Mw = 45100) in the production of electrode 3.

(Production of electrode 10)
Electrode 10 was obtained in the same manner except that H-2 was changed to P-53 (Mn = 11000, Mw = 50100) in preparation of electrode 3.

[Production of electrochemical display element]
(Production of electrochemical display element 1)
On the periphery of the electrode 2 bordered with an olefin-based sealant containing 10% glass spherical bead spacers with an average particle diameter of 40 μm as a volume fraction, polyvinyl alcohol (average polymerization degree 3500, saponification degree 87% ) 20% by mass of Titanium Dioxide CR-90 manufactured by Ishihara Sangyo Co., Ltd. was added to 2% by mass of isopropanol solution, and the mixed liquid dispersed with an ultrasonic disperser was applied so that the film thickness after drying was 20 μm. Then, after drying at 15 ° C. for 30 minutes to evaporate the solvent, it was dried in an atmosphere at 45 ° C. for 1 hour. After spraying glass spherical bead-shaped spacers having an average particle diameter of 20 μm on the obtained titanium dioxide layer, the electrode 2 and the electrode 1 were bonded and 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.

(Production of electrochemical display elements 2 to 16)
In the production of the electrochemical display element 1, electrochemical display elements 2 to 16 were produced in the same manner except that the electrolyte solution and the electrode were changed to the combinations shown in Table 1.

<< Evaluation of electrochemical display element >>
The following evaluation was performed about the produced electrochemical display elements 1-20.

(Reflectance stability)
When both electrodes of the display element are connected to both terminals of the constant voltage power source, a voltage of +1.5 V is applied for 1.5 seconds, and then a voltage of -1.5 V is applied for 1 second to display gray The reflectance at a wavelength of 550 nm was measured with a spectrocolorimeter CM-3700d manufactured by Konica Minolta Sensing. The driving was performed a total of 10 times under similar driving conditions, and the average value of the obtained reflectances was defined as R _ave1 . Further, after driving repeatedly 20,000 times, an average value R _ave2 of the _reflectance was obtained by the same method. ΔR _BK1 = | R _ave1 −R _ave2 | was used as an index of stability of reflectance when ΔR _BK1 was repeatedly driven. Here, the smaller the value of ΔR _BK1, the better the stability of the reflectance when it is repeatedly driven.

(Rewriting speed)
Connect both electrodes of the 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. the reflectance of the wavelength of 550nm was measured with a spectrocolorimeter CM-3700d manufactured by Konica Minolta sensing Inc. when is grayed Te, the obtained value was defined as R _BK2. Here, the smaller the value of R _BK2 is, the faster the black display rewriting speed is.

  The evaluation results are shown in Table 1.

  From the table, it can be seen that the electrochemical display element of the present invention is excellent in reflectance stability and rewriting speed when repeatedly driven.

Claims (7)

  A modified electrode comprising an electrode material on a substrate and a redox polymer compound immobilized on the electrode material via a chemical bond, wherein the redox polymer compound comprises two or more redox monomers. A modified electrode, characterized in that it is a copolymer.   The modified electrode according to claim 1, wherein at least one of the redox monomers has a spacer between a redox group and a reactive group capable of causing polymerization.   The modified electrode according to claim 1, wherein the redox monomer is a metallocene monomer.   The modified electrode according to claim 3, wherein the metallocene monomer is a ferrocene derivative. The redox polymer compound is —COOH, —P═O (OH) ₂ , —OP═O (OH) ₂ , —NCO or —Si (R ₁ ) _{3 -n} (OR ₂ ) _n (R ₁ , R ₂ 5 represents an alkyl group, and n represents an integer of 1 to 3. The modified electrode according to any one of claims 1 to 4, wherein the modified electrode has a group.   The electrochemical display element characterized by using the modified electrode of any one of Claims 1-5 for at least one among a pair of electrodes which oppose.   The electrochemical display element according to claim 6, wherein white and black are displayed using color development by electrochemical reduction precipitation of a metal salt and decoloration by electrochemical oxidation dissolution.