WO2009110292A1 - Electrochemical display device - Google Patents

Abstract

Disclosed is an electrochemical display device having improved display stability after long time storage. The electrochemical display device is characterized by having an electrolyte layer between opposite electrodes and containing, in the electrolyte layer, a polymer having at least one repeating unit which is composed of a monomer having a cyclic carbonate structure, a lactone structure or a dioxolane structure in a molecule.

Description

Electrochemical display element

The present invention relates to an 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, conventional liquid crystal displays and CRTs, and in recent years, light-emitting types such as organic EL displays are mainly used. In particular, when the electronic information is document information, it is necessary to watch the browsing means for a relatively long time, and these actions are not necessarily human-friendly means. It is known that eyes are fatigued, inconvenient to carry, reading posture is limited, it is necessary to adjust the line of sight to a static screen, and power consumption increases when reading for a long time.

As a display means that compensates for these drawbacks, a reflection type display that uses external light and does not consume power for image retention (memory type) is known, but has sufficient performance for the following reasons. It's hard to say.

That is, the method using a polarizing plate such as a reflective liquid crystal has a low reflectance of about 40% and is difficult to display white, and many of the manufacturing methods used for producing the constituent members are not easy. 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.

An electrodeposition method (hereinafter abbreviated as ED) using metal or metal salt dissolution and precipitation is known as a display method that eliminates the drawbacks of the above-described methods. 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). ~ See 3). An electrochromic (EC) element whose color changes electrochemically has been proposed as having a high contrast and a clear display.

In these ED / EC elements, a polymer binder is added to the electrolyte layer for the purpose of increasing the viscosity of the electrolyte and making it pseudo-solid for improving the handleability. As a result of examining the characteristics of the display element when these polymer binders are added, the present inventor has found that the conventional polymer binder has a problem in the display stability of the display element during storage over time.
U.S. Pat. No. 4,240,716 Japanese Patent No. 3428603 JP 2003-241227 A

The present invention has been made in view of the above problems, and an object thereof is to provide a display element having improved display stability during storage over time.

The above problem could be solved by the following configuration.

(1) Electrochemistry characterized by having an electrolyte layer between opposing electrodes and containing a polymer having a repeating unit composed of a monomer having a cyclic carbonate structure, a lactone structure or a dioxolane structure in the molecule. Display element.

(2) The electrochemical display element according to (1), wherein the monomer is represented by the following general formula (M1).

[Wherein, P represents a polymerizable ethylenically unsaturated bond group, L ₁ represents an arylene group or a carbonyl group, and L ₂ represents a divalent linking group. X represents a methylene group which may have a substituent or a carbonyl group. R ₅ represents an arbitrary substituent, and n represents 0, 1, 2, or 3. ]
(3) The electrochemical display element according to (1), wherein the monomer is represented by the following general formula (M2).

[Wherein, P represents a polymerizable ethylenically unsaturated bond group, L ₁ represents an arylene group or a carbonyl group, and L ₂ represents a divalent linking group. Y represents an atomic group necessary for forming a lactone ring structure. R ₅ represents an arbitrary substituent, and n represents 0, 1, 2, or 3. ]
(4) A metal salt compound is contained between the counter electrodes, and the counter electrode is driven so as to cause reduction deposition and oxidation dissolution of a metal element contained in the metal salt compound. The electrochemical display element according to any one of (1) to (3).

(5) The electrochemical display element according to (4), wherein the metal salt compound is a silver salt compound.

(6) The electrochemical display element according to (5), wherein the compound represented by the general formula (1) or the general formula (2) is contained between the counter electrodes.

General formula (1)
R ₇ -SR ₈
[Wherein, R ₇ and R ₈ each represent a substituted or unsubstituted hydrocarbon group, and R ₇ and R ₈ may be bonded to each other to form a ring. However, when a ring containing an S atom is formed, an aromatic ring is not formed. ]

[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 ₉ 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 ₉ is They may be the same or different and may be linked together to form a condensed ring. ]
(7) The electrochemical display element as described in any one of (1) to (6) above, wherein an electrochromic compound is contained between the counter electrodes.

(8) The electrochemical display element according to (7), wherein the electrochromic compound is represented by the following general formula (A).

[Wherein, R ₁ represents a substituted or unsubstituted aryl group, and R ₂ and R ₃ each represent a hydrogen atom or a substituent. X represents> N—R ₄ , an oxygen atom or a sulfur atom, and R ₄ represents a hydrogen atom or a substituent. ]
(9) The electrochemical display device according to (8), wherein R ₁ in the general formula (A) is a substituted or unsubstituted phenyl group.

(10) The electrochemical display element according to any one of (1) to (9), wherein a volatile solvent is not substantially contained between the counter electrodes.

(11) Between the counter electrodes, a plurality of types of compounds selected from the metal salt compounds and the electrochromic compounds are contained, and color colors other than white, black, and black are displayed by driving the counter electrodes. 10. The electrochemical display device according to any one of (1) to (9), wherein

(12) The electrochemical display element according to (11), wherein the black display is colored by reduction precipitation of the metal salt compound.

(13) The electrochemical display element according to any one of (1) to (12), wherein a porous white scattering layer is contained between the counter electrodes.

According to the present invention, a display element with improved display stability during storage over time can be obtained.

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 was able to obtain a display element having improved display stability during storage over time by including the polymer of the present invention in the electrolyte layer.

Hereinafter, details of the present invention will be described.

The polymer of the present invention is a polymer having at least one repeating unit composed of a monomer having a cyclic carbonate structure, a lactone structure or a dioxolane structure (also referred to as a monomer of the present invention) in the molecule. The polymer of the present invention has a chemical structure site having a large electronic polarization in the molecule, and the good affinity between this partial structure and other ionic substances contained in the electrolyte contributes to the stability of ionic conduction. Furthermore, it contributes to improving the display stability during storage over time.

The cyclic carbonate structure means a cyclic structure in which —O—CO—O— structures are connected by an alkylene group, and examples thereof include ethylene carbonate and trimethylene carbonate. The monomer having a cyclic carbonate structure in the molecule is preferably a monomer in which these cyclic carbonate structure and an ethylenically unsaturated structure are linked by a linking group. Similarly, the monomer having a lactone structure or a dioxolane structure in the molecule is preferably a monomer in which a lactone structure, a dioxolane structure and an ethylenically unsaturated structure are connected by a linking group. These monomers may be substituted with an arbitrary substituent at a substitutable position. The lactone structure is preferably a 5-membered or 6-membered ring, and the dioxolane structure is preferably 1,3-dioxolane.

The polymer of the present invention may be a homopolymer of these monomers or a copolymer with other comonomers. As the polymer of the present invention, a copolymer of the monomer of the present invention and an ethylenically unsaturated monomer having a polyoxyalkylene group is preferable, and a monomer having an acidic group such as acrylic acid, methacrylic acid, styrenesulfonic acid, and the like. These copolymers are preferred.

In the general formula (M1), P represents a polymerizable ethylenically unsaturated bond group, L ₁ represents an arylene group or a carbonyl group, and L ₂ represents a divalent linking group. X represents a methylene group which may have a substituent or a carbonyl group. R ₅ represents an arbitrary substituent, and n represents 0, 1, 2, or 3.

When X is a methylene group, a 1,3-dioxolane structure is formed, and when X is a carbonyl group, an ethylene carbonate structure is formed.

When L ₁ represents an arylene group, these may further have a substituent. As the arylene group represented by L ₁ , a phenylene group is preferable, and a p-phenylene group is particularly preferable.

Examples of the linking group represented by L ₂ include an oxygen atom, a nitrogen atom, a sulfur atom, a carbonyl group, a sulfonyl group, an alkylene group, an arylene group, a heteroarylene group, or a group obtained by combining these.

When the group represented by L ₁ is a carbonyl group, L ₂ is preferably bonded to L ₁ via an oxygen atom or a nitrogen atom.

The substituent represented by R ₅ is not particularly limited, and examples thereof include alkyl groups (eg, methyl group, ethyl group, n-propyl group, isopropyl group, tert-butyl group, n-pentyl group, n-hexyl group). Group, n-octyl group, n-dodecyl group, trifluoromethyl group, etc.), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), aryl group (eg, phenyl group, naphthyl group, etc.), acylamino group (eg, , Acetylamino group, benzoylamino group etc.), alkylthio group (eg methylthio group, ethylthio group etc.), arylthio group (eg phenylthio group, naphthylthio group etc.), alkenyl group (eg vinyl group, 2-propenyl group, etc.) 3-butenyl group, 1-methyl-3-propenyl group, 3-pentenyl group, 1-methyl-3-bute Group, 4-hexenyl group, cyclohexenyl group, etc.), halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), alkynyl group (eg propargyl group etc.), heterocyclic group (eg pyridyl group, thiazolyl group) Group, oxazolyl group, imidazolyl group, etc.), alkylsulfonyl group (eg, methylsulfonyl group, ethylsulfonyl group etc.), arylsulfonyl group (eg, phenylsulfonyl group, naphthylsulfonyl group etc.), alkylsulfinyl group (eg, methylsulfinyl group) Group), arylsulfinyl group (for example, phenylsulfinyl group), phosphono group, acyl group (for example, acetyl group, pivaloyl group, benzoyl group), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethyl group) Aminocarbonyl Group, butylaminocarbonyl group, cyclohexylaminocarbonyl group, phenylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexyl) Aminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), sulfonamide groups (for example, methanesulfonamide group, benzenesulfone) Amide group etc.), cyano group, alkoxy group (eg methoxy group, ethoxy group, propoxy group etc.), aryloxy group (eg phenoxy group, naphthyl) Oxy group etc.), heterocyclic oxy group, siloxy group, acyloxy group (eg acetyloxy group, benzoyloxy group etc.), sulfonic acid group, sulfonic acid salt, aminocarbonyloxy group, amino group (eg amino group, Ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, etc.), anilino group (for example, phenylamino group, chlorophenylamino group, toluidino group, anisidino group, naphthylamino group) 2-pyridylamino group, etc.), imide group, ureido group (for example, methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2- Pyridylaminourei Group), alkoxycarbonylamino group (eg methoxycarbonylamino group, phenoxycarbonylamino group etc.), alkoxycarbonyl group (eg methoxycarbonyl group, ethoxycarbonyl group, phenoxycarbonyl etc.), aryloxycarbonyl group (eg phenoxy) Carbonyl groups, etc.), heterocyclic thio groups, thioureido groups, carboxyl groups, carboxylic acid salts, hydroxy groups, mercapto groups, nitro groups and the like.

N is preferably 0 or 1.

In the general formula (M2), P represents a polymerizable ethylenically unsaturated bond, L ₁ represents an arylene group or a carbonyl group, and L ₂ represents a divalent linking group. Y represents an atomic group necessary for forming a lactone ring structure. R ₅ represents an arbitrary substituent, and n represents 0, 1, 2, or 3.

In the general formula (M2), Y represents an atomic group necessary for forming a lactone structure together with —CO—O—. As the lactone ring to be formed, a 5-membered ring or a 6-membered ring is preferable.

P, L ₁ , L ₂ and R ₅ in the general formula (M2) have the same meanings as those in the general formula (M1).

Specific examples of the monomers represented by the general formulas (M1) and (M2) are shown below, but are not limited thereto.

Examples of the ethylenically unsaturated monomer having a polyoxyalkylene group, which is a comonomer used in a preferred embodiment of the present invention, include acrylates, methacrylates, acrylamides, and methacrylamides substituted with a polyoxyalkylene group. .

Poly (oxyalkylene) acrylates and methacrylates are commercially available hydroxypoly (oxyalkylene) materials such as trade name “Pluronic” (Pluronic (Asahi Denka Kogyo Co., Ltd.)), Adeka Polyether (Asahi Denka Kogyo Co., Ltd.). ), Carbowax [Carbowax (Glico Products)], Triton [Toriton (Rohm and Haas)] and P.I. E. What is marketed as G (made by Daiichi Kogyo Seiyaku Co., Ltd.) can be manufactured by making it react with acrylic acid, methacrylic acid, acrylic chloride, methacrylic chloride, acrylic anhydride, etc. by a well-known method. Separately, poly (oxyalkylene) diacrylate produced by a known method can also be used.

Commercially available monomers include Blemmer PE-90, Blemmer PE-200, Blemmer PE-350, Blemmer AE-90, Blemmer AE-200 as a hydroxyl-terminated polyalkylene glycol mono (meth) acrylate manufactured by NOF Corporation. Blemmer AE-400, Blemmer PP-1000, Blemmer PP-500, Blemmer PP-800, Blemmer AP-150, Blemmer AP-400, Blemmer AP-550, Blemmer AP-800, Blemmer 50PEP-300, Blemmer 70PEP-350B , Blemmer AEP series, Blemmer 55PET-400, Blemmer 30PET-800, Blemmer 55PET-800, Blemmer AET series, Blemmer 30PPT-800, Buremer Ma 50PPT-800, Blemmer 70PPT-800, Blemmer APT series, Brenmer 10PPB-500B, such as Brenmer 10APB-500B and the like.

Similarly, Blemmer PME-100, Blemmer PME-200, Blemmer PME-400, Blemmer PME-1000, Blemmer PME-4000, Blemmer AME-400, Blemmer as alkyl-terminated polyalkylene glycol mono (meth) acrylates manufactured by NOF Corporation. 50POEP-800B, Blemmer 50AOEP-800B, Blemmer PLE-200, Blemmer ALE-200, Blemmer ALE-800, Blemmer PSE-400, Blemmer PSE-1300, Blemmer ASE series, Blemmer PKEP series, Blemmer AKEP series, Blemmer AE-300 , Blemmer ANE-1300, Blemmer PNEP series, Blemmer PNPE series, Blemmer 43AN P-500, Bremer 70ANEP-550, etc., and Kyoeisha Chemical Co., Ltd. light ester MC, light ester 130MA, light ester 041MA, light acrylate BO-A, light acrylate EC-A, light acrylate MTG-A, light acrylate 130A, Examples include light acrylate DPM-A, light acrylate P-200A, light acrylate NP-4EA, and light acrylate NP-8EA.

Poly (oxyalkylene) acrylamide and methacrylamide can be produced by reacting polyoxyalkylenes substituted with amino groups with acrylic acid, methacrylic acid, acrylic chloride, methacrylic chloride or acrylic anhydride by a known method.

As the polyoxyalkylene substituted with an amino group, for example, the following compounds can be easily obtained.

SUNBRIGHT TPA Series (Amino-PEGs) manufactured by NOF Corporation:
General formula CH ₃ O (CH ₂ CH ₂ O) _n —CH ₂ CH ₂ CH ₂ NH ₂
SUNBRIGHT MEPA-20H (average molecular weight 2,000)
SUNBRIGHT MEPA-50H (average molecular weight 5,000)
SUNBRIGHT MEPA-12T (average molecular weight 12,000)
SUNBRIGHT MEPA-20T (average molecular weight 20,000)
SUNBRIGHT MEPA-30T (average molecular weight 30,000)
Hydroxy-PEG-Amine manufactured by NOF Corporation:
General formula HO (CH ₂ CH ₂ O) _n —CH ₂ CH ₂ CH ₂ NH ₂
SUNBRIGHT HO-020PA (average molecular weight 2,000)
SUNBRIGHT HO-034PA (average molecular weight 3,400)
SUNBRIGHT HO-050PA (average molecular weight 5,000)
Amino-PEG-Carboxylic acid manufactured by NOF Corporation:
General formula HCl · H ₂ N—CH ₂ CH ₂ CH ₂ O (CH ₂ CH ₂ O) _n — (CH ₂ ) ₅ COOH
SUNBRIGHT PA-020HC (average molecular weight 2,000)
SUNBRIGHT PA-034HC (average molecular weight 3,400)
SUNBRIGHT PA-050HC (average molecular weight 5,000)
Other,
Amino-dPEG ^™ acid, Amino-dPEG ^™ t-butyl ester, Amino-dPEG ^™ alcohol, m-dPEG ^™ amine, etc. manufactured by Toyobo Co., Ltd. can also be used.

Examples of other comonomers that can be used in the present invention include the following monomers.

Acrylic esters: methyl acrylate, ethyl acrylate, propyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate, trimethylolpropane monoacrylate, benzyl acrylate, methoxybenzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, etc.
Methacrylic acid esters: methyl methacrylate, ethyl methacrylate, propyl methacrylate, chloroethyl methacrylate, 2-hydroxyethyl methacrylate, trimethylolpropane monomethacrylate, benzyl methacrylate, methoxybenzyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, etc.
Acrylamides: acrylamide, N-alkylacrylamide (alkyl group having 1 to 3 carbon atoms, such as methyl, ethyl, propyl), N, N-dialkylacrylamide, N-hydroxyethyl-N-methylacrylamide, N-2-acetamidoethyl-N-acetylacrylamide and the like. In addition, as alkyloxyacrylamide, methoxymethylacrylamide, butoxymethylacrylamide, etc.
Methacrylamide: methacrylamide, N-alkylmethacrylamide, N-hydroxyethyl-N-methylmethacrylamide, N-2-acetamidoethyl-N-acetylmethacrylamide, methoxymethylmethacrylamide, butoxymethylmethacrylamide, etc.
Allyl compounds: allyl esters (for example, allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate, etc.), allyloxyethanol, etc.
Vinyl ethers: alkyl vinyl ethers (eg, hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethyl hexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether, hydroxy Ethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether, etc.)
Vinyl esters: vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl valate, vinyl caproate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, vinyl butoxyacetate, vinyl lactate, vinyl -Β-phenylbutyrate, vinylcyclohexylcarboxylate, etc.
N-vinylamides: N-vinylformamide (VFA), N-vinyl-N-methylformamide (VMFA), N-vinylacetamide (VAA), N-vinyl-N-methylacetamide (VMAA), N-vinylpyrrolidone ( NVP), N-vinylcaprolactam (NVC), N-vinyloxazolidone (VOX), 5-methyl-N-vinyloxazolidone (5-MeVOX), N-vinylsuccinimide (VSI), N-vinylphthalimide (VPI), N-vinylmaleimide (VMI), N-vinylimidazole (VIZ), etc.
Dialkyl itaconates: dimethyl itaconate, diethyl itaconate, dibutyl itaconate, etc.
Dialkyl esters or monoalkyl esters of fumaric acid: dibutyl fumarate, etc.
Other examples include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, acrylonitrile, methacrylonitrile, maleilonitrile, and styrene.

In the polymer of the present invention, each structural unit can take an arbitrary sequence. Therefore, in the case of a copolymer, the polymer of the present invention may be a random copolymer, an alternating copolymer, or a block copolymer.

Further, the mass average molecular weight of the polymer of the present invention is not particularly limited, but is preferably 1000 or more, more preferably 1,000,000 or less, and 5,000 or more and 50,000 or less. Is particularly preferred.

When the polymer of the present invention is used for an electrolyte, the mass ratio is preferably 0.01% or more and 90% or less with respect to the total mass of the electrolyte.

Polymerization methods include radical polymerization, anionic polymerization, and cationic polymerization. In addition, when it is necessary to control the molecular weight, molecular weight distribution, and stereoregularity, a polymerization method called precision polymerization represented by living polymerization may be used.

Generally, as a production process for obtaining a polymer, there are a bulk polymerization process, a suspension polymerization process, an emulsion polymerization process, a gas phase polymerization process, a solution polymerization process, and the like. These production processes may be appropriately determined according to the properties of the target polymer.

When the polymer of the present invention is used as a display element, it is necessary to remove the remaining monomer after the completion of the polymerization reaction and to reduce the molecular weight of the copolymer in order not to reduce the light transmittance. In many cases, the solution polymerization process is adopted among the above processes. Furthermore, among the solution polymerization processes, the average molecular weight and molecular weight distribution due to differences in production batches are small, and a reproducible copolymer can be easily obtained. A so-called dropping polymerization method in which the monomer solution dissolved in is dropped into an organic solvent maintained at a constant temperature is preferably used.

As the polymerization initiator used in the production of the polymer of the present invention, those that generate radicals efficiently by heat are preferable. Examples of such a polymerization initiator include azo compounds such as 2,2′-azobisisobutyronitrile and dimethyl-2,2′-azobisisobutyrate; 2,5-dimethyl-2,5- And organic peroxides such as bis (tert-butylperoxy) hexane.

When producing the polymer of the present invention, a chain transfer agent may be used. By using a chain transfer agent, when a low molecular weight polymer is produced, the amount of the polymerization initiator used can be reduced, and the molecular weight distribution of the resulting polymer can be reduced.

Suitable chain transfer agents include, for example, 1-butanethiol, 2-butanethiol, 1-octanethiol, 1-decanethiol, 1-tetradecanethiol, cyclohexanethiol, 2-methyl-1-propanethiol, 2-mercapto Examples include ethanol.

The amount of the polymerization initiator used is not particularly limited, but it is usually preferably 1 to 20 mol% based on the total amount of monomers used. The amount of chain transfer agent used is not particularly limited, but it is usually preferably 1 to 20 mol% with respect to the total amount of monomers used.

The polymerization temperature is not particularly limited, but is usually preferably 50 ° C. or higher, and preferably 150 ° C. or lower.

As the organic solvent used in the dropping polymerization method, a solvent capable of dissolving any of the chain transfer agent when the monomer used, the polymerization initiator and the resulting polymer, and the chain transfer agent are used in combination is preferable. Examples of such an organic solvent include 1,4-dioxane, isopropyl alcohol, acetone, tetrahydrofuran, methyl ethyl ketone, methyl isobutyl ketone, γ-butyrolactone, propylene glycol monomethyl ether acetate (hereinafter also referred to as “PGMEA”), ethyl lactate. Etc.

A polymer solution produced by a method such as solution polymerization may be prepared with a suitable solvent viscosity with a good solvent such as 1,4-dioxane, acetone, THF, methyl isobutyl ketone, γ-butyrolactone, PGMEA, and ethyl lactate, if necessary. After dilution, the polymer may be purified by dropping it into a large amount of poor solvent such as methanol or water to precipitate the polymer. This process is generally called reprecipitation and is very effective for removing unreacted monomers, polymerization initiators, and the like remaining in the polymerization solution.

[Metal salt compounds]
The metal salt compound that can be used in the present invention is a salt containing a metal species that can be repeatedly dissolved and precipitated by driving the counter electrode on at least one electrode on the counter electrode. Any compound may be used. Preferred metal species are silver, bismuth, copper, nickel, iron, chromium, zinc and the like, and particularly preferred metal species are silver and bismuth from the viewpoint of black color tone and redox potential.

[Silver salt compound]
In the electrochemical display device of the present invention, the silver salt compound in which the metal salt compound contained in the electrolyte is silver or a compound containing silver in the chemical structure is preferable. The compound containing silver or silver in the chemical structure in the present invention is a general term for compounds such as silver oxide, silver sulfide, metallic silver, silver colloidal particles, silver halide, silver complex compounds, silver ions, Phase state species such as solid state, solubilized state in liquid, and gas state, and charged state species such as neutral, anionic, and cationic are not particularly limited.

[Basic configuration of electrochemical display element 1: Black and white display]
In the electrochemical display element of the present invention, the ED display portion is provided with a pair of opposing electrodes. The electrode 1 which is one of the counter electrodes close to the ED display portion is provided with a transparent electrode such as an ITO electrode, and the other electrode 2 is provided with a metal electrode such as a silver electrode. An electrolyte containing a metal salt compound that can be used in the present invention is supported between the electrode 1 and the electrode 2, and by applying a voltage of positive and negative polarity between the counter electrodes, the electrode 1 and the electrode For example, when the metal salt is silver, the reduction state black silver image and the oxidation state transparent silver state can be reversibly switched.

[Basic configuration of electrochemical display element 2: Multicolor display]
In the electrochemical display element of the present invention, the display portion is provided with a pair of opposing electrodes. A transparent electrode such as an ITO electrode is provided on the electrode 1 which is one of the counter electrodes close to the display portion, and a metal electrode such as a silver electrode is provided on the other electrode 2. An electrolyte containing a metal salt compound and an electrochromic compound are held between the electrode 1 and the electrode 2, and a metal salt is formed on the electrode 1 and the electrode 2 by applying a positive / negative bipolar voltage between the counter electrodes. A compound or an electrochromic compound is oxidized and reduced, and color display can be performed by utilizing a difference in coloring state between the two compounds in redox state and a white scatterer disposed between electrodes. The difference in the colored state can be controlled by the polarity of the voltage applied to both electrodes and the voltage threshold for color development and decoloration. As the metal salt compound and the electrochromic compound, plural kinds of compounds can be used as necessary.

(Porous white scattering layer)
In the present invention, a porous white scattering layer may be provided between the counter electrodes from the viewpoint of further increasing display contrast and white display reflectance.

The porous white scattering layer applicable to the present invention can be formed by applying and drying a water admixture of a water-based polymer that does not dissolve in an electrolyte solvent and a white pigment.

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, acid 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, organic substances such as trimethylolethane, triethanolamine acetate, trimethylcyclosilane, etc. Treated titanium dioxide 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 is substantially insoluble 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, cellulose derivatives, natural compounds such as polysaccharides such as starch, gum arabic, dextran, pullulan and carrageenan, polyvinyl alcohol, polyvinyl pyrrolidone, acrylamide polymers, and their Examples include synthetic polymer compounds such as derivatives. 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, the superabsorbent polymer described in JP-A No. 64-13546, pages 71 to 75, US Pat. No. 4,960,681, JP-A No. 62-245260, and the like. That is, a homopolymer of vinyl monomers having —COOM or —SO ₃ M (M is a hydrogen atom or an alkali metal) or these vinyl monomers or other vinyl monomers (for example, sodium methacrylate, ammonium methacrylate, potassium acrylate) Etc.) are also used. Two or more of these binders can be used in combination.

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

Polymers dispersed in an aqueous solvent include natural rubber latex, styrene butadiene rubber, butadiene rubber, nitrile rubber, chloroprene rubber, isoprene rubber and other latexes, polyisocyanate, epoxy, acrylic, silicone, 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 water-based polyurethane resin described in JP-A-10-76621 is preferably used.

The term “not soluble in an electrolyte solvent” as used in the present invention 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 quantification method using a gas chromatogram.

In the present invention, the water admixture 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 by volume, more preferably 0.3 to 0.05.

In the present invention, the medium for applying the water mixture of the water-based compound and the white pigment may be at any position as long as it is on the constituent element between the counter electrodes of the display element, but on at least one electrode surface of the counter electrode. It is preferable to give. 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 roller Examples include a coater, a slide hopper coater, a gravure coater, a kiss roll coater, a bead coater, a cast coater, a spray coater, a calendar coater, and an extrusion coater.

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

Porous as used in the present invention refers to the formation of a porous white scattering material by applying a water mixture of the water-based compound and the white pigment on the electrode and drying it, and then the silver or silver has a chemical structure on the scattering material. After supplying the electrolyte solution containing the compound contained in it, it can be sandwiched between the counter electrodes, a potential difference can be applied between the counter electrodes, and a dissolution and precipitation reaction of silver can be caused, and the ionic species can move between the electrodes Say that.

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

Examples of hardeners used in the present invention include, for example, US Pat. No. 4,678,739, column 41, 4,791,042, JP-A-59-116655, Examples of the hardening agent described in JP-A-62-245261, JP-A-61-18942, JP-A-61-249054, JP-A-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 among hardeners. Moreover, when using polyvinyl alcohol, it is preferable to use boron-containing compounds such as boric acid and metaboric acid.

These hardeners are used in an amount of 0.001 to 1 g, preferably 0.005 to 0.5 g, per 1 g of the aqueous compound. It is also possible to adjust the humidity during heat treatment or curing reaction in order to increase the film strength.

In the electrochemical display element of the present invention, the electrolyte preferably contains at least one compound represented by the general formula (1) or the general formula (2).

In the general formula (1), R ₇ and R ₈ each represent a substituted or unsubstituted hydrocarbon group, and these include a linear 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 forming a ring containing an S atom, an aromatic ring is not formed. Each element adjacent to the S atom is preferably a carbon atom.

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, silver or a compound containing silver is solubilized by coexisting with a compound containing a chemical structural species that interacts with silver that causes a coordinate bond with silver or a weak covalent bond with silver. It is common to use a means for converting to. As the chemical structural species, a halogen atom, a mercapto group, a carboxyl group, an imino group, and the like are known. However, in the present invention, a thioether group is also useful as a silver solvent, has little influence on coexisting compounds, and is a solvent. It is characterized by high solubility in water.

Specific examples of the compound represented by the general formula (1) that can be used in the present invention are shown below, but the present invention is not limited to these exemplified compounds.

1-1: CH ₃ SCH ₂ CH ₂ OH
1-2: HOCH ₂ CH ₂ SCH ₂ CH ₂ OH
1-3: HOCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OH
1-4: HOCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OH
1-5: HOCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ OH
1-6: HOCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ OH
1-7: H ₃ CSCH ₂ CH ₂ COOH
1-8: HOOCCH ₂ SCH ₂ COOH
1-9: HOOCCH ₂ CH ₂ SCH ₂ CH ₂ COOH
1-10: HOOCCH ₂ SCH ₂ CH ₂ SCH ₂ COOH
1-11: HOOCCH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ COOH
1-12: HOOCCH ₂ CH ₂ SCH ₂ CH ₂ CH ₂ SCH ₂ CH (OH) CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ COOH
_{1-13: 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
1-14: H ₃ CSCH ₂ CH ₂ CH ₂ NH ₂
1-15: H ₂ NCH ₂ CH ₂ SCH ₂ CH ₂ NH ₂
1-16: H ₂ NCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NH ₂
1-17: H ₃ CSCH ₂ CH ₂ CH (NH ₂ ) COOH
1-18: H ₂ NCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ NH ₂
1-19: H ₂ NCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ NH ₂
1-20: H ₂ NCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NH ₂
1-21: HOOC (NH ₂ ) CHCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ CH (NH ₂ ) COOH
1-22: HOOC (NH ₂ ) CHCH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH (NH ₂ ) COOH
1-23: HOOC (NH ₂ ) CHCH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH (NH ₂ ) COOH
1-24: H ₂ N (O =) CCH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ C (
= O) NH ₂
1-25: H ₂ N (O═) CCH ₂ SCH ₂ CH ₂ SCH ₂ C (═O) NH ₂
1-26: H ₂ NHN (O =) CCH ₂ SCH ₂ CH ₂ SCH ₂ C (= O) NHNH ₂
1-27: H ₃ C (O =) CNHCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NHC (= O)
CH ₃
1-28: H ₂ NO ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SO ₂ NH ₂
1-29: NaO ₃ SCH ₂ CH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ CH ₂ SO ₃ Na
1-30: H ₃ CSO ₂ NHCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NHSO ₂ CH ₃
1-31: H ₂ N (NH) CSCH ₂ CH ₂ SC (NH) NH ₂ .2HBr
1-32: H ₂ N (NH) CSCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ SC (NH) NH ₂ .2HCl
1-33: H ₂ N (NH) CNHCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NHC (NH)
NH ₂ · 2HBr
1-34: [(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 1-2 is particularly preferable from the viewpoint that the objective effect of the present invention can be exhibited.

Next, the compound represented by the general formula (2) that can be used in the present invention will be described.

In the general formula (2), 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 ₉ 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 ₉ 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 (2) include Li, Na, K, Mg, Ca, Zn, and Ag. Examples of the quaternary ammonium include H ₄ N, (CH _{3) 4 N, (C 4} H 9) 4 N, (CH 3) 3 NC 12 H 25, (CH 3) 3 NC 16 H 33, include _{(CH 3) 3 NCH 2 C} 6 H 5 and the like.

Examples of the nitrogen-containing heterocycle represented by Z in the general formula (2) 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. , A benzothiazole ring, a benzoselenazole ring, a naphthoxazole ring, etc., among which a triazole ring is preferable.

Examples of the halogen atom represented by R ₉ in the general formula (2) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group include, for example, 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 a phenylsulfonyl group and a 4-chlorophenylsulfonyl group. 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, and butyroyl groups. Examples of the arylcarbonyl group include a benzoyl group and an alkylbenzoyl group. Examples of the acyloxy group include acetyl group. Examples of the heterocyclic group include oxazole ring, thiazole ring, triazole ring, selenazole ring, tetrazole ring, oxadiazole ring, thiadiazole ring, thiazole group, and the like. Jin 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 include those having further substituents.

Next, preferred specific examples of the compound represented by the general formula (2) will be shown, but the present invention is not limited to these compounds.

Of the above-exemplified compounds, Exemplified Compounds 2-12, 2-18, and 2-20 are particularly preferable from the viewpoint that the objective effects of the present invention can be exhibited.

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

Formula (1)
0 ≦ [X] / [M] ≦ 0.01
In the present invention, the halogen atom means an iodine atom, a chlorine atom, a bromine atom, or a fluorine atom. When [X] / [M] is larger than 0.01, X ⁻ → X ₂ is generated during the redox reaction of the metal ion, and X ₂ easily cross-oxidizes with the reduced form of the metal ion to reduce the metal ion. It is preferable that the halogen atom molar concentration is as low as possible with respect to the metal ion molar concentration, because it oxidizes the body and decreases memory properties and becomes one of the causes of uneven reflectance fluctuations during repeated driving. In the present invention, 0 ≦ [X] / [M] ≦ 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.

[Electrochromic compound]
In the display element of the present invention, the above-described electrolyte contains an electrochromic compound, and when the counter electrode is driven, a color change caused by an oxidation and reduction reaction of the electrochromic compound, and a metal salt on at least one of the counter electrode It is preferable to perform multicolor display of three or more colors by black display, white display, and color display other than black by using the color change caused by reduction precipitation and oxidation dissolution of the metal element contained in the compound.

That is, as an electrochromic compound (hereinafter abbreviated as EC compound) that can be used in the present invention, the optical absorption property (color and light transmittance) of a substance reversibly changes due to electrochemical redox. Any compound may be used as long as it exhibits a phenomenon (electrochromism). Specific compounds include "Electrochromic display" (June 28, 1991, Sangyo Tosho Co., Ltd.) pp27-124, "Development of chromic materials" (November 15, 2000, CMC Corporation) pp81 And the compounds described in -95 and the like.

One of the electrochromic compounds that can be preferably used in the display device of the present invention is preferably a metal complex in which at least one organic ligand having a carbon-nitrogen double bond as a partial structure is coordinated. .

The type of metal constituting the metal complex is not particularly limited as long as the organic ligand having a carbon-nitrogen double bond as a partial structure can be coordinated, but group 8 of the periodic table (iron, Ruthenium, osmium), Group 9 (cobalt, rhodium, iridium), lanthanoids (cisprosium, ytterbium, lutetium, etc.), nickel and copper are preferred, and iron and cobalt are particularly preferred.

The metal complex that can be used in the present invention is characterized in that the colored state is changed by an oxidation-reduction reaction, and the colored state is preferably changed in the range of −3.5V to 3.5V. It is preferable that the coloring state changes in the range of −1.5V to 1.5V.

Specific examples of the organic ligand having a carbon-nitrogen double bond as a partial structure include hydrazones (eg, hydrazone, azine, semicarbazone, isosemicarbazone, carbohydrazone, hydrazone acid, hydrazidine, amidrazon, etc. ), Oximes (eg, oxime, hydroxymic acid, amidoxime, etc.), imines, nitrogen-containing heterocyclic compounds (eg, pyrazole, imidazole, thiazole, oxazole, triazole, oxadiazole, thiadiazole, pyridine, pyridazine, pyrimidine, Pyrazine, triazine, benzimidazole, purine, quinoline, isoquinoline, quinoxaline, phenanthroline, porphyrin, phthalocyanine, pyrroline, imidazoline, pyrazoline, pyrazolone, oxazoline, thiazoline, etc.) And the like.

Of these organic ligands, multidentate ligands are preferred, and bidentate or tridentate ligands are particularly preferred. Specific examples include bipyridines, terpyridines, phenanthrolines, tetrazolylpyridines, pyridylquinazolines, bis-isoquinolines, pyridylazines, pyridylbenzimidazoles, and the like.

Further, the organic ligand having a carbon-nitrogen double bond as a partial structure that can be used in the present invention is preferably a compound represented by the following general formula [I].

In the general formula [I], R ₃₁ , R ₃₂ , R ₃₃ and R ₃₄ are each independently a hydrogen atom, amino group, hydroxy group, mercapto group, alkoxy group, alkyl group, alkenyl group, alkynyl group or aryl group. Alternatively, it represents a heterocyclic group, and these substituents may further have a substituent. R ₃₁ and R ₃₂ , R ₃₂ and R ₃₃ and R ₃₃ and R ₃₄ may be linked to each other to form an aromatic or non-aromatic cyclic structure, and any position on the cyclic structure May have a substituent.

R ₃₁ and R ₃₂ , R ₃₂ and R _33, or R ₃₃ and R ₃₄ are preferably a compound in which each is linked to each other to form an aromatic or non-aromatic cyclic structure.

When R ₃₁ and R ₃₂ are connected to each other to form a cyclic structure, the organic ligand having a carbon-nitrogen double bond as a partial structure that can be used in the present invention is represented by the following general formula [II]. It is preferred that

In the general formula [II], R ₃₃ and R ₃₄ have the same meanings as in the general formula [I], and Z represents an atomic group necessary for forming a cyclic structure together with C═N. Further, these cyclic structures may have a substituent at any substitutable position. These ring structures are preferably aromatic heterocyclic structures.

Specific examples of the cyclic structure skeleton in which the substituent is omitted are illustrated below, but are not limited thereto. In addition, in each cyclic structure skeleton shown below, * represents a bonding position.

In the above general formula [I], when R ₃₁ and R ₃₂ and R ₃₃ and R ₃₄ are connected to each other to form a cyclic structure, the carbon-nitrogen double bond that can be used in the present invention has a partial structure. Is preferably a compound represented by the following general formula [III].

In the above general formula [III], Z ₁ and Z ₂ together with C═N represent an atomic group necessary for forming a cyclic structure. Further, the compound represented by the general formula [III] may have a substituent at any substitutable position on the two cyclic structures. There is no restriction | limiting in particular as this substituent, The substituent shown as a concrete cyclic structure of the said general formula [I] may be sufficient.

In the above general formula [I], when R ₃₂ and R ₃₃ are connected to each other to form a cyclic structure, an organic ligand having a carbon-nitrogen double bond as a partial structure which can be used in the present invention. Is preferably a compound represented by the following general formula [IV].

In the general formula [IV], R ₃₁ and R ₃₄ have the same meanings as those in the general formula [I], and Z ₃ represents an atomic group necessary for forming a cyclic structure together with two carbon atoms. To express. Further, this cyclic structure may have a substituent at any substitutable position.

Among the above general formulas [I] to [IV], particularly preferred are compounds represented by the following general formula [V] or general formula [VI].

In the general formula [V], R ₃₁ and R ₃₄ have the same meanings as those in the general formula [I]. In the general formula [VI], R ₄₁ and R ₄₂ each represents an alkyl group which may have a substituent.

The organic ligand having a carbon-nitrogen double bond as a partial structure that can be used in the present invention is chemically or physically adsorbed to the electrode from the viewpoint of adhesion to the electrode surface and film durability. It preferably has at least one adsorptive group.

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

The adsorptive group of the present invention is preferably a chemisorbable group, and examples of chemisorbable adsorptive groups include —COOH, —P—O (OH) ₂ , —OP═O (OH) ₂ and -Si (OR) ₃ (R represents an alkyl group).

Hereinafter, the organic ligand having a carbon-nitrogen double bond as a partial structure that can be used in the present invention, and the organic ligand further having an adsorptive group that is chemically or physically adsorbed on the electrode surface Although the specific example of is shown, it is not limited to these.

Next, examples of metal complexes in which at least one organic ligand having a carbon-nitrogen double bond as a partial structure used in the present invention is coordinated are shown, but the invention is not limited thereto. In the table, M represents a central metal, L represents an organic ligand, n represents the number of ligands, and A represents a counter salt for neutralizing the charge.

Moreover, as another preferable electrochromic compound, the compound represented by the general formula (A) can be exemplified.

Hereinafter, the details of the electrochromic compound represented by the general formula (A) that can be preferably used in the present invention will be described.

In the general formula (A), R ₁ represents a substituted or unsubstituted aryl group, and R ₂ and R ₃ each represent a hydrogen atom or a substituent, but the substitution represented by R ₁ , R ₂ , or R ₃ Specific examples of the group include, for example, an alkyl group (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, etc.), cycloalkyl group (for example, cyclohexyl group, cyclopentyl group). Etc.), alkenyl group, cycloalkenyl group, alkynyl group (for example, propargyl group), glycidyl group, acrylate group, methacrylate group, aromatic group (for example, phenyl group, naphthyl group, anthracenyl group, etc.), heterocyclic group ( For example, pyridyl group, thiazolyl group, oxazolyl group, imidazolyl group, furyl group, pyrrolyl group, pyrazinyl group, pyrimidinyl , Pyridazinyl group, selenazolyl group, sriphoranyl group, piperidinyl group, pyrazolyl group, tetrazolyl group, etc.), alkoxy group (for example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, cyclopentyloxy group, hexyloxy group, cyclohexyloxy group) Group), aryloxy group (for example, phenoxy group, etc.), alkoxycarbonyl group (for example, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, etc.), aryloxycarbonyl group (for example, phenyloxycarbonyl group, etc.) ), Sulfonamide group (for example, methanesulfonamide group, ethanesulfonamide group, butanesulfonamide group, hexanesulfonamide group, cyclohexanesulfonamide group, benzenesulfonamide group, etc.), Rufamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, phenylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), urethane group ( For example, methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, phenylureido group, 2-pyridylureido group, etc.), acyl group (for example, acetyl group, propionyl group, butanoyl group, hexanoyl group, cyclohexanoyl group) Group, benzoyl group, pyridinoyl group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentyl) Aminocarbonyl group, cyclohexylaminocarbonyl group, phenylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), acylamino group (eg, acetylamino group, benzoylamino group, methylureido group, etc.), amide group (eg, acetamido group, propion) Amide group, butanamide group, hexaneamide group, benzamide group, etc.), sulfonyl group (eg, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, phenylsulfonyl group, 2-pyridylsulfonyl group, etc.), sulfonamide Group (for example, methylsulfonamide group, octylsulfonamide group, phenylsulfonamide group, naphthylsulfonamide group, etc.), amino group (for example, amino group, ethylamino group, dimethylamino group) Butylamino group, cyclopentylamino group, anilino group, 2-pyridylamino group, etc.), halogen atom (eg chlorine atom, bromine atom, iodine atom etc.), cyano group, nitro group, sulfo group, carboxyl group, hydroxyl group, phosphono Examples include a group (for example, phosphonoethyl group, phosphonopropyl group, phosphonooxyethyl group), oxamoyl group, and the like. Further, these groups may be further substituted with these groups.

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

R ₂ and R ₃ are preferably an alkyl group, a cycloalkyl group, an aromatic group, or a heterocyclic group, more preferably one of R ₂ and R ₃ is a phenyl group, the other is an alkyl group, and more preferably R ₂ and R ₃ are both phenyl groups.

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

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

[Organic solvent]
An organic solvent can be used for the electrolyte layer of the present invention. Organic solvents include propylene carbonate, ethylene carbonate, γ-butrolactone, tetramethylurea, sulfolane, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone, 2- (N-methyl) -2-pyrrolidinone, hexamethyl Phosphortriamide, N-methylpropionamide, N, N-dimethylacetamide, N-methylacetamide, N, N dimethylformamide, N-methylformamide, butyronitrile, propionitrile, acetonitrile, acetylacetone, 4-methyl-2-pentanone 2-butanol, 1-butanol, 2-propanol, 1-propanol, ethanol, methanol, acetic anhydride, ethyl acetate, ethyl propionate, dimethoxyethane, diethoxyfuran, tetrahydrofuran, Ji glycol, diethylene glycol, triethylene glycol monobutyl ether, and water. Among these solvents, it is preferable to include at least one solvent having a freezing point of −20 ° C. or lower and a boiling point of 120 ° C. or higher.

Further, examples of the solvent that can be used in the present invention include J. 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 Electrolytes Handbook”, Vol. 1, Academic Press (1972). The organic solvent used for the electrolyte may be a single type or a mixture of solvents.

In the present invention, it is preferable that the electrolyte layer does not substantially contain a volatile solvent. Examples of such an organic solvent include various ionic liquids, phthalates having 8 or more carbon atoms, fatty acid esters, sorbitols, and the like.

[Electrolyte-Silver salt]
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 which does not have a nitrogen atom having a coordination property with halogen, carboxylic acid or silver, and for example, silver p-toluenesulfonate is preferable.

The silver ion concentration contained in the electrolyte that can be used in the present invention is preferably 0.2 mol / kg ≦ [Ag] ≦ 2.0 mol / kg. If the silver ion concentration is less than 0.2 mol / kg, it becomes a dilute silver solution, and the driving speed is delayed. If it is greater than 2 mol / kg, the solubility deteriorates, and precipitation tends to occur during low-temperature storage, which is disadvantageous. It is.

In the display element of the present invention, various constituent layers can be provided as necessary in addition to the constituent elements described above.

[Porous electrode containing metal oxide]
In the display element of the present invention, a porous electrode containing a metal oxide can also be used. In the display element of the present invention, the surface of the counter electrode that is not on the image observation side is protected by a porous electrode containing a metal oxide, so that silver or silver on the surface that is not on the image observation side is in a chemical structure. By finding that the oxidation-reduction reaction of the compound contained in the electrode is carried out on or in the porous electrode containing the metal oxide, it is possible to expand the choice of types of electrodes not on the image observation side and improve the durability. Can do.

Examples of the metal oxide constituting the porous electrode that can be used in the present invention include titanium oxide, silicon oxide, zinc oxide, tin oxide, Sn-doped indium oxide (ITO), antimony-doped tin oxide (ATO), and fluorine. Examples thereof include doped tin oxide (FTO), aluminum-doped zinc oxide, and the like, or a mixture thereof.

The porous electrode is formed by binding or contacting a plurality of fine particles of the metal oxide. The average particle diameter of the metal oxide fine particles is preferably 5 nm to 10 μm, more preferably 20 nm to 1 μm. The specific surface area of the metal oxide fine particles is preferably 1 × 10 ⁻³ to 1 × 10 ² m ² / g, more preferably 1 × 10 ⁻² to 10 m ² / g, according to the simple BET method. The metal oxide fine particles may have any shape such as an indefinite shape, a needle shape, and a spherical shape.

As a method for forming or binding metal oxide fine particles, a known sol-gel method, sintering method, microwave heating method, or the like can be employed. For example, 1) Journal of the Ceramic Society of Japan, 102, 2, p200 (1994), 2) Journal of Ceramic Industry Association 90, 4, p157, 3) J. of Non-Cryst. Solids, 82, 400 (1986) and the like. Also, use is made of a method in which titanium oxide dendrimer particles prepared by a vapor phase method are dispersed on a solution and coated on a substrate, and dried at a temperature of about 120 to 150 ° C. to remove the solvent to obtain a porous electrode. You can also. The metal oxide fine particles are preferably bound, and preferably have a resistance of 0.1 g or more, preferably 1 g or more with a continuous load type surface property measuring instrument (for example, a scratch tester).

Porous in the present invention means that a porous electrode is arranged, a potential difference is applied between the opposing electrodes, a silver dissolution precipitation reaction can be caused, and a penetrating state in which ionic species can move in the porous electrode. To tell.

(Electronic insulation layer)
In the display element of the present invention, an electronic 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 High porous membranes and pseudo-solid electrolyte membranes carrying an electrolyte in the voids, polymer porous membranes having voids, and porous materials of inorganic materials having a low relative dielectric constant such as silicon-containing compounds.

As a method for forming a porous film, a sintering method (fusion method) (particulate fusion of polymer fine particles or inorganic particles by using a binder, etc., and utilizing pores formed between particles), extraction method ( After forming a 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 Known forming methods such as a foaming method in which foaming is performed, a phase change method in which a mixture of polymers is phase-separated by operating a good solvent and a poor solvent, and a radiation irradiation method in which pores are formed by radiating various types of radiation Can be used.

Specifically, JP-A-10-30181, JP-A-2003-107626, JP-B-7-95403, Japanese Patent Nos. 2635715, 2849523, 29987474, 3066426, 3464513, 3483444. , 3535942 and 306203, the electronic insulating layer can be mentioned.

[Electrolyte material]
In the display element of the present invention, when the electrolyte is a liquid, the following compounds can be included in the electrolyte. KCl, KI, KBr, etc. as potassium compounds, LiBF ₄ , LiClO ₄ , LiPF ₆ , LiCF ₃ SO ₃ etc. as lithium compounds, tetraethylammonium perchlorate, tetrabutylammonium perchlorate, tetraethylammonium borofluoride as tetraalkylammonium compounds And tetrabutylammonium borofluoride and tetrabutylammonium halide. Further, the molten salt electrolyte composition described in paragraph numbers [0062] to [0081] of JP-A No. 2003-187881 can also be preferably used. Furthermore, a compound that becomes a redox pair such as I ⁻ / I ₃ ⁻ , Br ⁻ / Br ₃ ⁻ , and quinone / hydroquinone can be used.

Further, when the supporting electrolyte is solid, the following compounds exhibiting electron conductivity and ion conductivity can be contained in the electrolyte.

Vinyl fluoride polymer containing perfluorosulfonic acid, polythiophene, polyaniline, polypyrrole, triphenylamines, polyvinylcarbazoles, polymethylphenylsilanes, Cu ₂ S, Ag ₂ S, Cu ₂ Se, AgCrSe _2, etc. F-containing compounds such as chalcogenide, CaF ₂ , PbF ₂ , SrF ₂ , LaF ₃ , TlSn ₂ F ₅ , CeF ₃ , Li salts such as Li ₂ SO ₄ , Li ₄ SiO ₄ , Li ₃ PO ₄ , ZrO ₂ , CaO , Cd ₂ O ₃ , HfO ₂ , Y ₂ O ₃ , Nb ₂ O ₅ , WO ₃ , Bi ₂ O ₃ , AgBr, AgI, CuCl, CuBr, CuBr, CuI, LiI, LiBr, LiCl, LiAlCl ₄ , LiAlF ₄ , AgSBr, C ₅ H ₅ NHAg ₅ I ₆ , Rb ₄ Cu ₁₆ I ₇ Cl ₁₃ , Rb ₃ Cu ₇ Cl ₁₀ , LiN, Li ₅ N _I2 , Examples thereof include compounds such as Li ₆ NBr ₃ .

Further, a gel electrolyte can also be used as the supporting electrolyte. When the electrolyte is non-aqueous, oil gelling agents described in paragraph numbers [0057] to [0059] of JP-A No. 11-185836 can be used.

[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 (epoxides), 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. Further, compounds described on pages 71 to 75 of JP-A No. 64-13546 can be exemplified. 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 layer of the display device 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, color Preparations, hardeners, surfactants, thickeners, plasticizers, sliding agents, UV absorbers, anti-irradiation dyes, filter light absorbing dyes, antibacterial agents, polymer latex, heavy metals, antistatic agents, matting agents, etc. Can be contained as required. The auxiliary layer may be provided in a region sandwiched between the pair of counter electrodes, or may be provided in a region not sandwiched between the counter electrodes.

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

The types of compounds and their locations 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 996 III
Sensitizing dye 23 IV 648-649 996-8 IV
Desensitizing dye 23 IV 998 IV
Dye 25-6 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
A metallocene derivative can be used for the constituent layer of the display element of the present invention. A ferrocene derivative is preferably used as the metallocene derivative. Examples of ferrocene derivatives include ferrocene, methyl ferrocene, dimethyl ferrocene, ethyl ferrocene, propyl ferrocene, n-butyl ferrocene, t-butyl ferrocene, 1,1-dicarboxyferrocene, and the like. The metallocene derivatives can be used alone or in admixture of two or more.

〔Layer structure〕
The constituent layers between the counter electrodes of the display element of the present invention will be further described.

As a constituent layer according to the display element of the present invention, a constituent layer containing a hole transport material can be provided. Examples of hole transport materials include aromatic amines, triphenylene derivatives, oligothiophene compounds, polypyrroles, polyacetylene derivatives, polyphenylene vinylene derivatives, polythienylene vinylene derivatives, polythiophene derivatives, polyaniline derivatives, polytoluidine derivatives, CuI, CuSCN CuInSe ₂ , Cu (In, Ga) Se, CuGaSe ₂ , Cu ₂ O, CuS, CuGaS ₂ , CuInS ₂ , CuAlSe ₂ , GaP, NiO, CoO, FeO, Bi ₂ O ₃ , MoO ₂ , Cr ₂ O ₃ Etc.

〔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. Furthermore, 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, Japanese Patent Application Laid-Open No. Sho 62-253195 (pages 29 to 31). What was described as a support 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 described on 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. Among them, silver or a silver electrode having a silver content of 80% or more is advantageous for maintaining the reduced state of silver, Also excellent in prevention. The electrode can be produced by an existing method such as a vapor deposition method, a printing method, an ink jet method, a spin coating method, or a CVD method.

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, silicone, 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 electrochemical display elements]
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 as not to leak outside, also called sealing agent, epoxy resin, urethane resin, acrylic resin, vinyl acetate resin, ene-thiol resin, silicone resin, Curing types such as a thermosetting type, a photo-curing type, a moisture-curing type, and an anaerobic curing type such as a modified polymer resin can be used.

Columnar structures provide strong self-holding (strength) between substrates, for example, cylindrical bodies, square pillars, elliptical pillars, trapezoidal pillars arranged in a predetermined pattern such as a lattice arrangement. A columnar structure such as a body can be mentioned. Alternatively, stripes arranged at predetermined intervals may be used. This columnar structure is not a random array, it can maintain an appropriate interval between substrates, 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 cycle. It is preferable that the sequence is considered so as not to hinder. If the ratio of the area occupied by the columnar structure to 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 uniformly maintain the gap between the substrates, only the columnar structure may be provided, but both the spacer and the columnar structure may be provided, or only the spacer is used as a space holding member instead of the columnar structure. May be. 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.

[Screen printing]
In the present invention, a sealant, a columnar structure, an electrode pattern and the like can be formed by a screen printing method. In the screen printing method, a screen on which a predetermined pattern is formed is placed on an electrode surface of a substrate, and a printing material (a composition for forming a columnar structure, such as a photocurable resin) is placed on the screen. Then, the squeegee is moved at a predetermined pressure, angle, and speed. Thereby, the printing material is transferred onto the substrate through the pattern of the screen. Next, the transferred material is heat-cured and dried.

When the columnar structure is formed by the screen printing method, the resin material is not limited to a photocurable resin, and for example, a thermosetting resin such as an epoxy resin or an acrylic resin or a thermoplastic resin can also be used. As thermoplastic resins, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, polymethacrylate resin, polyacrylate resin, polystyrene resin, polyamide resin, polyethylene resin, polypropylene resin, fluororesin, polyurethane resin , Polyacrylonitrile resin, polyvinyl ether resin, polyvinyl ketone resin, polyether resin, polyvinyl pyrrolidone resin, saturated polyester resin, polycarbonate resin, chlorinated polyether resin and the like. The resin material is preferably used in the form of a paste by dissolving the resin in an appropriate solvent.

After the columnar structure or the like is formed on the substrate as described above, a spacer is provided on at least one of the substrates as desired, and the pair of substrates are overlapped with the electrode formation surfaces facing each other to form an empty cell. . A pair of stacked substrates is heated while being pressed from both sides, whereby the display cells are obtained. In order to obtain a display element, an electrolyte composition may be injected between substrates by a vacuum injection method or the like. Alternatively, the electrolyte composition may be dropped on one substrate when the substrates are bonded together, and the liquid crystal composition may be sealed simultaneously with the bonding of the substrates.

[Electrochemical display element driving method]
In the electrochemical display element of the present invention, it is preferable to perform a driving operation in which a metal is deposited by applying a voltage equal to or higher than the deposition overvoltage, and the metal is continuously deposited by applying a voltage equal to or lower than the deposition overvoltage. By performing this driving operation, the writing energy can be reduced, the driving circuit load can be reduced, and the writing speed as a screen can be improved. It is generally known that overvoltage exists in electrode reactions in the electrochemical field. For example, overvoltage is described in detail on page 121 of “Introduction to Chemistry of Electron Transfer-Introduction to Electrochemistry” (published by Asakura Shoten in 1996). Since the display element of the present invention can also be regarded as an electrode reaction between the electrode and silver in the electrolyte, it can be easily understood that overvoltage exists even in silver dissolution precipitation. Since the magnitude of the overvoltage is governed by the exchange current density, it is possible to continue silver black precipitation by applying a voltage equal to or lower than the precipitation overvoltage after the formation of silver black as in the present invention. However, it is presumed that electron injection can be easily performed with little excess electric energy.

In addition, the method for controlling the transparent state and the colored state of the electrochemical display device of the present invention can be determined based on the deposition voltage and dissolution overvoltage of the metal ion of the metal salt compound, and the threshold voltage for coloring and decoloring of the electrochromic compound. It is preferable. For example, in the case of a display element having a silver complex and an iron complex between counter electrodes, a colored state other than black is shown when no voltage is applied, a white state is shown on the oxidation side, and a black state is shown on the reduction side. As an example of the control method in this case, the iron complex is oxidized by applying a voltage nobler than the redox potential of the iron complex to show a white state, and between the redox potential of the iron complex and the precipitation overvoltage of the silver complex. By applying a voltage, the iron complex is reduced and returned to a colored state other than black, and by applying a voltage that is lower than the silver complex precipitation overvoltage, silver is deposited on the electrode, indicating a black state, and the iron complex is redox. There is a method of dissolving and decoloring the deposited silver by applying a voltage lower than the potential.

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 Japanese Patent Application Laid-Open No. 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.

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
Polymers shown in Table 1 were synthesized. Under a nitrogen atmosphere, 100 g of PGMEA (propylene glycol monomethyl ether acetate) was placed in a flask equipped with a nitrogen inlet, a stirrer, a condenser and a thermometer, and the temperature of the hot water bath was raised to 80 ° C. while stirring. Next, a mixture having the following composition was dropped into the flask over 6 hours at a constant rate using a dropping device, and then kept at 80 ° C. for 1 hour.

Monomer Amount (g) shown in Table 1 below
AIBN 0.2g
PGMEA 50g
Subsequently, the said polymerization liquid was dripped in about 30 times amount diisopropyl ether / heptane 1: 1 mixed solution, and the gummy white precipitate was obtained. After removing the supernatant as decane, about the same amount of diisopropyl ether / heptane 1: 1 mixed solution was again added and washed. The obtained polymer was dried at 40 ° C. under reduced pressure to obtain the intended polymer.

The following are shown in the table.

Monomer 1: Monomer of the present invention Monomer 2: Ethylenically unsaturated monomer having polyoxyalkylene group Monomer 4: Ethylenically unsaturated monomer having acidic group Monomer 3: Other ethylenically unsaturated monomer PME-400: Blemmer PME- 400 (manufactured by NOF), methacrylate having-(EO) _m —CH ₃ (m≈9) PSE-400: BLEMMER PSE-400 (manufactured by NOF), — (EO) _m —C ₁₈ H ₃₇ (m ≈ 9) methacrylate (EO; ethyleneoxy group)
BMA: butyl methacrylate,
AA: Acrylic acid Example 2
<< Production of display element >>
[Production of Display Element 1]
(Preparation of electrolyte 1)
Add bismuth chloride 90mg and lithium iodide 180mg in 2.5g of dimethyl sulfoxide and dissolve completely, then add 0.6g of titanium dioxide and 150mg of polyethylene glycol (PEG, average molecular weight 500,000) and heat to 120 ° C. While stirring for 1 hour, an electrolytic solution 1 was obtained.

(Production of electrode 1)
An ITO (Indium Tin Oxide Indium Tin Oxide) film with 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 porous carbon electrode having an electrode thickness of 0.8 μm, 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 a size of 2 cm × 4 cm using a known method. An electrode 2 having a volume fraction of 10% and having an olefin sealant as an edge was produced.

(Preparation of display element 1)
The electrode 2 and the electrode 1 were bonded together so that the striped electrodes were orthogonal to each other with the electrolytic solution 1 interposed therebetween, and then pressed and heated to solidify the sealant, whereby the display element 1 was produced.

(Preparation of display element 2)
In the production of the display element 1, the same procedure was performed except that the electrolytic solution 2 added with 0.1 g of 1,1′-di-n-octyl-4,4′-bipyridinium dichloride was used instead of bismuth chloride and lithium iodide. Thus, the display element 2 was produced.

(Preparation of display element 3)
Display element 3 was produced in the same manner as display element 1 except that polyethylene glycol in electrolyte solution 1 of display element 1 was changed to the same mass of the synthetic polymer of Example 1 (Comparative P2).

(Preparation of display element 4)
The display element 2 is the same as the display element 2 except that the polyethylene glycol in the electrolytic solution 2 of the display element 2 is changed to polyvinyl alcohol having the same mass (PVA235, manufactured by Kuraray Co., Ltd., average polymerization degree 3500, saponification degree 87%). 4 was produced.

(Preparation of display element 5)
A display element 5 was produced in the same manner as the display element 3 except that the synthetic polymer (comparative P2) of the electrolytic solution 1 of the display element 3 was changed to a synthetic polymer (P1) having the same mass.

(Preparation of display element 6)
A display element 6 was produced in the same manner as in the display element 4 except that the polyvinyl alcohol in the electrolytic solution 2 of the display element 4 was changed to a synthetic polymer (P8) having the same mass.

(Preparation of display elements 7 and 8)
Display elements 7 and 8 were produced in the same manner as the display element 5 except that the synthetic polymer (P1) of the display element 5 was changed to synthetic polymers (P6) and (P9) having the same mass.

(Preparation of display elements 9 and 10)
Display elements 9 and 10 were produced in the same manner as the display element 6 except that the synthetic polymer (P8) of the display element 6 was changed to synthetic polymers (P2) and (P4) having the same mass.

(Preparation of display element 11)
Display element except that polyethylene glycol in electrolyte solution 1 of display element 1 is changed to synthetic polymer (P5) of the same mass, bismuth chloride is changed to equimolar p-toluenesulfonic acid, and lithium iodide is changed to equimolar lithium chloride. In the same manner as in Example 1, a display element 11 was produced.

(Preparation of display elements 12 to 15)
In the display element 11, dimethyl sulfoxide is added to propylene carbonate (PC) having the same mass, and lithium chloride is added to equimolar compounds (1-2), (1-4), (2-12), and (2-18). Display elements 12 to 15 were fabricated in the same manner as the display element 11 except for the change.

(Preparation of display elements 16 to 17)
The dimethyl sulfoxide of the display element 10 is γ-butyrolactone (γBL) of the same mass, the synthetic polymer (P4) is (P10), the electrochromic compound is an exemplary compound (A-70), and (A-105), respectively. Display elements 16 and 17 were produced in the same manner as the display element 10 except that the change was made.

(Preparation of display element 18)
A display element 18 was produced in the same manner as the display element 13 except that the propylene carbonate of the display element 13 was changed to N-ethyl-N-methylimidazolium hexafluoroborate having the same mass.

(Preparation of display element 19)
A display element 19 was produced in the same manner as the display element 13 except that the propylene carbonate of the display element 13 was changed to N-hexyl-pyridinium hexafluoroborate having the same mass.

(Preparation of electrode 3)
Polyvinyl alcohol (average polymerization degree 3500, saponification degree 87%) is formed on the electrode 2 bordered by an olefin-based sealant containing 10% glass spherical beads having an average particle diameter of 40 μm as a volume fraction in the periphery. After applying a mixed solution in which 20% by mass of titanium oxide was dispersed in an isopropanol solution containing 2% by mass with an ultrasonic disperser at a thickness of 100 μm, and then drying at 15 ° C. for 30 minutes to evaporate the solvent, The electrode 3 was produced by drying in an atmosphere at 45 ° C. for 1 hour.

(Preparation of display element 20)
A display element 20 was produced in the same manner as the display element 19 except that titanium dioxide was removed from the electrolyte solution of the display element 19 and the electrode 3 was used instead of the electrode 2.

(Preparation of display element 21)
A display element 21 was produced in the same manner as the display element 17 except that γ-butyrolactone was changed from the electrolyte solution of the display element 17 to N-hexyl-pyridinium hexafluoroborate having the same mass.

(Preparation of display element 22)
Display element 22 was fabricated in the same manner as display element 21 except that titanium dioxide was removed from the electrolyte solution of display element 21 and electrode 3 was used instead of electrode 2.

(Preparation of display element 23)
A display element 23 was produced in the same manner as the display element 22 except that 0.3 g of tetrathiafulvalene was added to the electrolyte solution of the display element 22.

(Preparation of display element 24)
Same as display element 22 except that 0.1 g of silver p-toluenesulfonate, 0.15 g of exemplary compound (1-4) and 0.05 g of synthetic polymer (P5) were added to the electrolyte solution of display element 22. Thus, the display element 24 was produced.

<< Evaluation of display element >>
[Evaluation of display stability during storage over time]
For each of the manufactured display elements, a driving condition is set such that the L ^* value at the time of black display is 65 with a D65 light source using a spectrocolorimeter CM-3700d manufactured by Konica Minolta Sensing. The L ^* value, a ^* value, and b ^* value when whitening was performed under the conditions were measured and designated as L ₁ , a ₁ , and b ₁ , respectively. Thereafter, the display element is left in an environment of 85 ° C. and relative humidity 65% for 2 days to perform an accelerated test for storage over time, and then when the whitening is performed again under the same driving conditions as before the accelerated test. ^{The *} value, a ^* value, and b ^* value were measured and designated as L ₂ , a ₂ , and b ₂ , respectively.

ΔE = [(L ₂ −L ₁ ) ² + (a ₂ −a ₁ ) ² + (b ₂ −b ₁ ) ² ] ^1/2 was calculated from the obtained measured values as an evaluation value of color tone fluctuation. . Table 1 shows the result of obtaining the relative value of ΔE for each display element when the value of ΔE of the display element 1 is 1. The smaller the value of ΔE, the smaller the color tone variation in repeated driving, and the better.

The display elements 1 to 22 obtained black and white or white-color display. For the display elements 23 and 24, white-black-color multicolor display was obtained. The display elements 23 and 24 show the evaluation value of display by an electrochromic compound.

As is clear from the results shown in Table 2, the display element having the structure defined in the present invention is not limited to the other components contained in the electrolyte due to the effect of the polymer of the present invention having a chemical structure portion having a large electronic polarization in the molecule. It can be seen that the affinity between these ionic substances is improved, the change in display characteristics when the display element is stored over time is reduced, and the color tone variation resistance is excellent.

Further, only the same performance was obtained even when the synthetic polymer (comparative P2) of the display element 3 was changed to comparative P1.

Further, even when the electrochromic compound was changed to the compounds represented by the general formulas [I] to [IV], the same results as in Table 2 were obtained.

Claims (13)

1. Electrochemistry having an electrolyte layer between opposing electrodes, and containing in the molecule a polymer having at least one repeating unit composed of a monomer having a cyclic carbonate structure, a lactone structure or a dioxolane structure in the molecule Display element.
2. The electrochemical display element according to claim 1, wherein the monomer is represented by the following general formula (M1).
   

   

   
   [Wherein, P represents a polymerizable ethylenically unsaturated bond group, L ₁ represents an arylene group or a carbonyl group, and L ₂ represents a divalent linking group. X represents a methylene group which may have a substituent or a carbonyl group. R ₅ represents an arbitrary substituent, and n represents 0, 1, 2, or the third term. ]
3. The electrochemical display element according to claim 1, wherein the monomer is represented by the following general formula (M2).
   

   

   
   [Wherein, P represents a polymerizable ethylenically unsaturated bond group, L ₁ represents an arylene group or a carbonyl group, and L ₂ represents a divalent linking group. Y represents an atomic group necessary for forming a lactone ring structure. R ₅ represents an arbitrary substituent, and n represents 0, 1, 2, or the third term. ]
4. 2. The counter electrode according to claim 1, wherein a metal salt compound is contained between the counter electrodes, and the counter electrode is driven so as to cause reduction precipitation and oxidation dissolution of a metal element contained in the metal salt compound. 4. The electrochemical display device according to any one of items 3 to 3.
5. The electrochemical display element according to claim 4, wherein the metal salt compound is a silver salt compound.
6. The electrochemical display element according to claim 5, wherein the compound represented by the general formula (1) or the general formula (2) is contained between the counter electrodes.
   General formula (1)
   R ₇ -SR ₈
   [Wherein R ₇ and R ₈ 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 ₉ 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 ₉ is They may be the same or different and may be linked together to form a condensed ring. ]
7. The electrochemical display element according to any one of claims 1 to 6, wherein an electrochromic compound is contained between the counter electrodes.
8. The electrochemical display element according to claim 7, wherein the electrochromic compound is represented by the following general formula (A).
   

   

   
   [Wherein, R ₁ represents a substituted or unsubstituted aryl group, and R ₂ and R ₃ each represent a hydrogen atom or a substituent. X represents> N—R ₄ , an oxygen atom or a sulfur atom, and R ₄ represents a hydrogen atom or a substituent. ]
9. The electrochemical display element according to claim 8, wherein R ₁ in the general formula (A) is a substituted or unsubstituted phenyl group.
10. The electrochemical display element according to any one of claims 1 to 9, wherein a volatile solvent is not substantially contained between the counter electrodes.
11. A plurality of kinds of compounds selected from the metal salt compound and the electrochromic compound are contained between the counter electrodes, and a color color other than white, black, and black is displayed by driving the counter electrode. The electrochemical display element according to any one of claims 1 to 9, wherein:
12. 12. The electrochemical display element according to claim 11, wherein the black display is colored by reduction precipitation of the metal salt compound.
13. The electrochemical display element according to any one of claims 1 to 12, further comprising a porous white scattering layer between the counter electrodes.