JP2008203611A - Display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display element which is reduced in color tone fluctuation of white during repetitive driving. <P>SOLUTION: The display element contains an electrolyte containing silver or a compound including the silver in a chemical structure between counter electrodes and performs the driving operation of the counter electrodes so as to give rise to the dissolution deposition of the silver. The electrolyte contains the compound expressed by general formula (A) and the compound expressed by general formula (1): R<SB>7</SB>-S-R<SB>8</SB>or general formula (2). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

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

  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. It is necessary to keep a close eye on this browsing means, and these actions are not necessarily human-friendly means. Generally, as a disadvantage of the light-emitting display, eyes flicker due to flickering, inconvenient to carry, limited reading posture In addition, it is known that it is necessary to adjust the line of sight to a still screen, and that power consumption increases when read for a long time.

  As a display means to compensate for these drawbacks, a reflection type display 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 production 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 aggregation of electrophoretic particles. In addition, the electrochromic display element can be driven at a low voltage of 3 V or less, but the color quality of black or color (for example, yellow, magenta, cyan, blue, green, red, etc.) is not sufficient and has a memory property. Therefore, there is a concern that a complicated film configuration such as a vapor deposition film is necessary for the display cell.

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

As a result of detailed examination of the techniques disclosed in each of the above-mentioned patent documents, the inventor has found that there is a problem that white tone fluctuations during whitening occur in the conventional technique when repeated driving is repeated. did.
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 of the present invention is to provide a display element in which variation in white color tone during repeated driving is reduced.

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

  1. A display element which contains an electrolyte containing silver or a compound containing silver in the chemical structure between the counter electrodes, and which drives the counter electrode so as to cause dissolution and precipitation of silver, wherein the electrolyte is: A display device comprising a compound represented by the general formula (A) and a compound represented by the following general formula (1) or general formula (2).

[Wherein, R _1, R ₂ each represent a hydrogen atom or a substituent, n represents an integer of 0-4. ]
General formula (1)
R ₇ -S-R 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. ]
2. 2. The display device according to 1 above, wherein the compound represented by the general formula (A) is the following general formula (B).

[Wherein, R ₁ and R ₂ each represent a hydrogen atom or a substituent. ]
3. 3. The display device according to 1 or 2, wherein the compound represented by the general formula (2) is a triazole derivative.

  4). The molar concentration of halogen ions or halogen atoms contained in the electrolyte is [X] (mol / kg), and the total molar concentration of silver contained in the electrolyte or the compound containing silver in the chemical structure is [Ag] ( The display element according to any one of the above items 1 to 3, which satisfies a condition defined by the following formula (1):

Formula (1)
0 ≦ [X] / [Ag] ≦ 0.01
5. 5. The display element according to any one of 1 to 4, wherein at least one of the counter electrodes is a fluorine-doped tin oxide (FTO) electrode.

  According to the present invention, it has been possible to provide a display element in which variation in white color tone during repeated driving is reduced.

  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 inventor of the present invention contains an electrolyte containing silver or a compound containing silver in a chemical structure between the counter electrodes, and the counter electrode so as to cause dissolution and precipitation of silver. A display element for driving an electrode, wherein the electrolyte contains the compound represented by the general formula (A) and the compound represented by the general formula (1) or the general formula (2). As a result of the present invention, the present inventors have found that a display element with reduced white color tone variation during repeated driving can be realized.

  Details of the present invention will be described below.

  The display element of the present invention contains an electrolyte containing silver or a compound containing silver in the chemical structure between the counter electrodes, and performs an operation of driving the counter electrode so as to cause dissolution and precipitation of silver. It is.

[Silver or a compound containing silver in the chemical structure]
Silver or a compound containing silver in the chemical structure according to 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, and 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 structure of display element]
In the display element of the present invention, a corresponding counter electrode is provided in the ED display portion. 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 having silver or a compound containing silver in the chemical structure is supported between the electrode 1 and the electrode 2, and by applying a voltage of both positive and negative polarity between the opposing electrodes, Thus, a silver oxidation-reduction reaction is performed, and a reduced black silver image and an oxidized transparent silver state can be reversibly switched.

[Compounds represented by general formula (A) and general formula (B)]
The compounds represented by formula (A) and formula (B) according to the present invention will be described.

In the general formula (A) and general formula (B), R ₁ and R ₂ each represent a hydrogen atom or a substituent, and examples of the substituent include a halogen atom, an oxygen atom, an alkyl group, an aryl group, and an alkylcarboxyl. Amido group, arylcarbonamido group, alkylsulfonamido group, arylsulfonamido group, alkoxy group, aryloxy group, alkylthio group, arylthio group, alkylcarbamoyl group, arylcarbamoyl group, carbamoyl group, alkylsulfamoyl group, arylsulfuryl group Famoyl group, sulfamoyl group, cyano group, alkylsulfonyl group, arylsulfonyl group, alkoxycarbonyl group, aryloxycarbonyl group, alkylcarbonyl group, arylcarbonyl group, acyloxy group, carboxyl group, carbonyl group, sulfoni Group, an amino group, a nitro group, hydroxy group, and a heterocyclic group.

  In the said general formula (A), n represents the integer of 0-4, Furthermore, it is preferable that it is a compound represented by general formula (B) whose n is 0.

  In the compounds represented by the general formula (A) and the general formula (B) according to the present invention, the molecular weight is preferably 94 or more and 150 or less, and a cyclic voltammetry method (for example, “organic conductor It is preferable that the redox half-wave potential measured by “Chemistry” by Gunji Saito, published on June 30, 2003, Maruzen Co., Ltd., page 25) is −1.5 V or more and +1.5 V or less.

  Specific examples of the aminopyridine derivative represented by the general formula (A) and the general formula (B) according to the present invention are shown below, but the present invention is not limited to these exemplified compounds.

  Among the above-exemplified compounds, the compound A-3, A-7 (compounds according to the general formula (B)), A-22, A are particularly preferable from the viewpoint that the objective effect of the present invention can be exhibited. -28 (the compound according to the general formula (A)) is preferable.

  The aminopyridine compound represented by the general formula (A) and the general formula (B) according to the present invention can be obtained according to a conventionally known synthesis method.

(Porous white scattering layer)
In this invention, you may have a porous white scattering layer from a viewpoint of raising a display contrast and a white display reflectance more.

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

  Examples of the white pigment applicable in the present invention include titanium dioxide (anatase type or rutile type), barium sulfate, calcium carbonate, aluminum oxide, zinc oxide, magnesium oxide and zinc hydroxide, magnesium hydroxide, magnesium phosphate, Magnesium hydrogen phosphate, alkaline earth metal salt, talc, kaolin, zeolite, acidic clay, glass, organic compounds such as polyethylene, polystyrene, acrylic resin, ionomer, ethylene-vinyl acetate copolymer resin, benzoguanamine resin, urea-formalin resin, A melamine-formalin resin, a polyamide resin, or the like may be used alone or in combination, or in a state having voids that change the refractive index in the particles.

In the present invention, among the white particles, titanium dioxide, zinc oxide, and zinc hydroxide are preferably used. In addition, titanium dioxide surface-treated with inorganic oxides (Al ₂ O ₃ , AlO (OH), SiO _2, etc.), in addition to these surface treatments, 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 does not substantially dissolve in the electrolyte solvent include a water-soluble polymer and a polymer dispersed in the water-based solvent.

  Examples of water-soluble compounds include proteins such as gelatin and gelatin derivatives, 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. Examples of gelatin derivatives include acetylated gelatin, phthalated gelatin, polyvinyl alcohol derivatives include terminal alkyl group-modified polyvinyl alcohol, terminal mercapto group-modified polyvinyl alcohol, and cellulose derivatives include hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, and the like. It is done.

Furthermore, research disclosure and those described in pages 71 to 75 of JP-A No. 64-13546, US Pat. No. 4,960,681, specification of JP-A No. 62-245260, etc. Highly water-absorbing polymers, ie, homopolymers 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) Copolymers with 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 aqueous polyurethane resin described in JP-A-10-76621 is preferably used.

  In the present invention, “substantially insoluble in an electrolyte solvent” is defined as a state in which the dissolved amount per kg of electrolyte solvent is 0 g or more and 10 g or less at a temperature of −20 ° C. to 120 ° C. The amount of dissolution can be determined by a known method such as a component determination method using a chromatogram or a gas chromatogram.

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

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

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

  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 given between the counter electrodes, and a dissolution and precipitation reaction of silver can occur, 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 aqueous compound with a curing agent during or after coating and drying the water mixture described above.

  Examples of the hardener used in the present invention include, for example, US Pat. No. 4,678,739, column 41, 4,791,042, JP-A-59-116655, Examples thereof include hardening agents 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.

[Compounds represented by general formulas (1) and (2)]
In the display element of the present invention, the electrolyte includes the compound represented by the general formula (A), and further includes at least one compound represented by the general formula (1) or the general formula (2). Features.

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 a ring containing an S atom is formed, an aromatic group is not taken. 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) according to 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 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 NHO ₂ SCH 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 object and effects of the present invention can be exhibited.

  Next, the compound represented by formula (2) according to 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 methyl, ethyl, propyl, i- Examples include propyl, butyl, t-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, octyl, dodecyl, hydroxyethyl, methoxyethyl, trifluoromethyl, benzyl, etc. Examples of the aryl group include phenyl, naphthyl and the like. Examples of the alkylcarbonamide group include acetylamino, propionylamino, butyroylamino and the like. Examples of the arylcarbonamide group include benzoylamino and the like. Examples of the sulfonamide group include methanesulfonyl. Minosulfonyl, ethanesulfonylamino group and the like, arylsulfonamide groups include, for example, benzenesulfonylamino group, toluenesulfonylamino group and the like, and aryloxy groups include, for example, phenoxy and the like, alkylthio Examples of the group include each group such as methylthio, ethylthio, and butylthio. Examples of the arylthio group include phenylthio group and tolylthio group. Examples of the alkylcarbamoyl group include methylcarbamoyl, dimethylcarbamoyl, Examples include ethyl carbamoyl, diethyl carbamoyl, dibutyl carbamoyl, piperidyl carbamoyl, morpholyl carbamoyl and the like, and aryl carbamoyl groups include, for example, phenyl carbamoyl, methyl phenyl carbamoyl Examples include groups such as vamoyl, ethylphenylcarbamoyl, and benzylphenylcarbamoyl. Examples of the alkylsulfamoyl group include methylsulfamoyl, dimethylsulfamoyl, ethylsulfamoyl, diethylsulfamoyl, and dibutylsulfamoyl. Examples of each group include moyl, piperidylsulfamoyl, morpholylsulfamoyl, and arylsulfamoyl groups include, for example, phenylsulfamoyl, methylphenylsulfamoyl, ethylphenylsulfamoyl, benzylphenylsulfamoyl. Examples of the alkylsulfonyl group include a methanesulfonyl group and an ethanesulfonyl group. Examples of the arylsulfonyl group include phenylsulfonyl and 4-chlorophenylsulfonyl. Examples of each group include p-toluenesulfonyl and the like. Examples of the alkoxycarbonyl group include groups such as methoxycarbonyl, ethoxycarbonyl, and butoxycarbonyl. Examples of the aryloxycarbonyl group include phenoxycarbonyl and the like. Examples of the alkylcarbonyl group include acetyl, propionyl, 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, although the preferable specific example of a compound represented by General formula (2) is shown, this invention is not limited to these compounds.

  Among the above-exemplified compounds, Exemplified Compounds 2-12 and 2-18 are particularly preferable from the viewpoint that the object and 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 or halogen atoms contained in the electrolyte is [X] (mol / kg), and silver contained in the electrolyte or the total silver of the compound containing silver in the chemical structure. When the molar concentration is [Ag] (mol / kg), it is preferable to satisfy the condition defined by the following formula (1).

Formula (1) 0 ≦ [X] / [Ag] ≦ 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] / [Ag] is larger than 0.01, X ⁻ → X ₂ is generated during the oxidation-reduction reaction of silver, and X ₂ easily cross-oxidizes with the blackened silver to dissolve the blackened silver. The molar concentration of the halogen atom is preferably as low as possible with respect to the molar concentration of silver because it becomes one of the factors that lower the memory property. In the present invention, 0 ≦ [X] / [Ag] ≦ 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.

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

  The silver ion concentration contained in the electrolyte according to 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, in addition to the above-described constituent elements, various constituent layers can be provided as necessary.

[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 according to the present invention include titanium oxide, silicon oxide, zinc oxide, tin oxide, Sn-doped indium oxide (ITO), antimony-doped tin oxide (ATO), and fluorine-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. It is preferable that the specific surface area of the metal oxide particles is ^{1 × 10 -3 ~1 × 10 2} m 2 / g by a simple BET method, more preferably from ^{1 × 10 -2 ~10m 2 / g} . 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. In addition, a method of obtaining a porous electrode by dispersing titanium oxide dendrimer particles prepared by a vapor phase method on a solution and applying the particles on a substrate and drying at a temperature of about 120 to 150 ° C. to remove the solvent is used. 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 electrical insulating layer can be provided.

  The electronic insulating layer applicable to the present invention may be a layer having both ionic conductivity and electronic insulating properties. For example, a solid electrolyte membrane in which a polymer or salt having a polar group is formed into a film, electronic insulating properties 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, Japanese Patent Application Laid-Open Nos. 10-30181, 2003-107626, 7-95403, Japanese Patent Nos. 2635715, 2849523, 29987474, 3066426, 3464513, 3483644. , 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. Moreover, the molten salt electrolyte composition described in paragraph numbers [0062] to [0081] of JP-A-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 a 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 .

  Moreover, a gel electrolyte can also be used as the supporting electrolyte. When the electrolyte is non-aqueous, the oil gelling agents described in paragraphs [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. Moreover, the compound as described in pages 71-75 of Unexamined-Japanese-Patent No. 64-13546 can be mentioned. Among these, the compounds preferably used are polyvinyl alcohols, polyvinyl pyrrolidones, hydroxypropyl celluloses, and polyalkylene glycols from the viewpoint of compatibility with various additives and improvement in dispersion stability of white particles.

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

  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 shown in these three research disclosures and their locations are listed below.

Additive RD17643 RD18716 RD308119
Page Classification Page Classification Page Classification Chemical sensitizer 23 III 648 Upper right 96 III
Sensitizing dye 23 IV 648-649 996-8 IV
Desensitizing dye 23 IV 998 IV
Dye 25-26 VIII 649-650 1003 VIII
Development accelerator 29 XXI 648 Upper right Anti-fogging agent / stabilizer
24 IV 649 Upper right 1006-7 VI
Brightener 24 V 998 V
Hardener 26 X 651 Left 1004-5 X
Surfactant 26-7 XI 650 Right 1005-6 XI
Antistatic agent 27 XII 650 Right 1006-7 XIII
Plasticizer 27 XII 650 Right 1006 XII
Slipper 27 XII
Matting agent 28 XVI 650 Right 1008-9 XVI
Binder 26 XXII 1003-4 IX
Support 28 XVII 1009 XVII
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 the ferrocene derivative 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. Also preferred are syndiotactic polystyrenes. 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. 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 body described in pages 44 to 149 of publicly known technology No. 5 (issued by Aztec Co., Ltd. on March 22, 1991) can also be used. Furthermore, RDNo. 308119, page 1009, Product Licensing Index, Volume 92, P108, “Supports”, and the like. In addition, a glass substrate or an epoxy resin kneaded with glass can be used.

〔electrode〕
In the display element of the present invention, it is preferable that at least one of the counter electrodes is a metal electrode. As the metal electrode, for example, known metal species such as platinum, gold, silver, copper, aluminum, zinc, nickel, titanium, bismuth, and alloys thereof can be used. The metal electrode is preferably a metal having a work function close to the redox potential of silver in the electrolyte. 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 the display element]
In the display element of the present invention, a sealant, a columnar structure, and spacer particles can be used as necessary.

  Sealing agent is for sealing so 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 in the display area of the display element is 1 to 40%, a practically sufficient strength as a display element can be obtained.

  A spacer may be provided between the pair of substrates for uniformly maintaining a gap between the substrates. Examples of the spacer include a sphere made of resin or inorganic oxide. Further, a fixed spacer having a surface coated with a thermoplastic resin is also preferably used. In order to 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.

[Display element driving method]
In the display element of the present invention, it is preferable to perform a driving operation in which silver black is precipitated by applying a voltage equal to or higher than the precipitation overvoltage and silver black is continuously precipitated by applying a voltage lower than the precipitation 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.

  The driving operation of the display element of the present invention may be simple matrix driving or active matrix driving. The simple matrix driving referred to in the present invention is a driving method in which current is sequentially applied to a circuit in which a positive line including a plurality of positive electrodes and a negative electrode line including a plurality of negative electrodes are opposed to each other in a vertical direction. Say that. By using simple matrix driving, there is an advantage that the circuit configuration and driving IC can be simplified and manufactured at low cost. The active matrix drive is a system in which scanning lines, data lines, and current supply lines are formed in a grid pattern, and are driven by TFT circuits provided in each grid pattern. Since switching can be performed for each pixel, there are merits such as gradation and memory function. For example, a circuit described in FIG. 5 of Japanese Patent Application Laid-Open No. 2004-29327 can be used.

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

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

Example 1
<< Production of display element >>
[Production of Display Element 1]
(Preparation of electrolyte 1)
In 2.5 g of dimethyl sulfoxide, 90 mg of sodium iodide, 50 mg of exemplary compound (A-22) and 75 mg of silver iodide were added and completely dissolved, and then 150 mg of polyvinyl pyrrolidone (average molecular weight 15000) was added to 120 ° C. The mixture was stirred for 1 hour while being heated to obtain an electrolytic solution 1.

(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 silver-palladium electrode having an electrode thickness of 0.8 μm, a pitch of 145 μm, and an electrode interval of 130 μm was formed on a 2 cm × 4 cm glass substrate having a thickness of 1.5 mm using a known method.

(Preparation of electrode 3)
Polyvinyl alcohol (average polymerization degree 3500, saponification degree 87%) is placed on the electrode 2 bordered with 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 is 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.

(Production of display element)
The electrodes 3 and 1 were bonded together so that the striped electrodes were orthogonal to each other, and then heated and pressed to produce an empty cell. The electrolytic solution 1 was vacuum-injected into the empty cell, and the injection port was sealed with an epoxy-based ultraviolet curable resin to produce a display element 1.

[Production of Display Element 2]
A display element 2 was produced in the same manner as in the production of the display element 1 except that the exemplified compound (A-22) of the electrolytic solution 1 was changed to the exemplified compound (2-19).

[Production of Display Element 3]
A display element 3 was produced in the same manner as in the production of the display element 1 except that 50 mg of the exemplary compound (1-2) was added to the electrolytic solution 1.

[Production of Display Element 4]
A display element 4 was produced in the same manner as in the production of the display element 1 except that 45 mg of the exemplary compound (A-28) was added to the electrolytic solution 1.

[Production of display elements 5 and 6]
In the production of the display elements 3 and 4, display elements 5 and 6 were produced in the same manner except that silver iodide in the electrolyte was changed to equimolar silver p-toluenesulfonate and sodium iodide was removed. did.

[Production of display element 7]
A display element 7 was produced in the same manner except that the exemplified compound (2-19) was changed to an equimolar example compound (2-12) in the production of the display element 6.

[Production of Display Element 8]
Display element 8 was prepared in the same manner as in the preparation of display element 5 except that the exemplary compound (A-28) was changed to an equimolar exemplary compound (A-3).

[Production of Display Element 9]
In the production of the display element 8, the display element 9 was produced in the same manner except that the ITO of the electrode 1 was changed to FTO.

<< Evaluation of display element >>
[Evaluation of color fluctuation resistance]
For each of the produced display elements, after obtaining a driving condition such that the L ^* value in the D65 light source of the spectrocolorimeter CM-3700d manufactured by Konica Minolta Sensing Co., Ltd. is 65, whitening is performed under this driving condition. The L ^* value, a ^* value, and b ^* value were measured and designated as L ₁ , a ₁ , and b ₁ , respectively. Thereafter, whitening-blackening was driven 1000 times under the driving conditions, and then L ^* value, a ^* value, and b ^* value when whitening was performed again were measured to be 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.

  As is apparent from the results shown in Table 1, it can be seen that the display element having the configuration defined in the present invention has reduced color tone fluctuation after repeated driving and is excellent in color tone fluctuation resistance.

Claims (5)

A display element which contains an electrolyte containing silver or a compound containing silver in the chemical structure between the counter electrodes, and which drives the counter electrode so as to cause dissolution and precipitation of silver, wherein the electrolyte is: A display device comprising a compound represented by the general formula (A) and a compound represented by the following general formula (1) or general formula (2).

[Wherein, R _1, R ₂ each represent a hydrogen atom or a substituent, n represents an integer of 0-4. ]
General formula (1)
R ₇ -S-R 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. ] The display element according to claim 1, wherein the compound represented by the general formula (A) is the following general formula (B).

[Wherein, R ₁ and R ₂ each represent a hydrogen atom or a substituent. ] The display device according to claim 1, wherein the compound represented by the general formula (2) is a triazole derivative. The molar concentration of halogen ions or halogen atoms contained in the electrolyte is [X] (mol / kg), and the total molar concentration of silver contained in the electrolyte or the compound containing silver in the chemical structure is [Ag] ( The display element according to any one of claims 1 to 3, wherein a condition defined by the following formula (1) is satisfied when the mole / kg) is satisfied.
Formula (1)
0 ≦ [X] / [Ag] ≦ 0.01 The display element according to claim 1, wherein at least one of the counter electrodes is a fluorine-doped tin oxide (FTO) electrode.