JPWO2008090710A1 - Display element - Google Patents

Abstract

The present invention provides a display element that has a high display speed, is excellent in durability even when repeatedly driven, and can maintain stable characteristics for a long period of time. This display element has an electrolyte containing a compound represented by the following general formula (1) between counter electrodes. [Chemical 1]

Description

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

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

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

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

  As a display method for solving the drawbacks of each of the above-described methods, there are an electrochromic display element (hereinafter abbreviated as EC method) and an electrodeposition method (hereinafter abbreviated as ED method) using dissolution precipitation of metal or metal salt. Are known. The EC method has the advantage of being capable of full-color display at a low voltage of 3V or less, a simple cell configuration, and excellent white quality. The ED method can also be driven at a low voltage of 3V or less and is a simple cell. There are advantages such as excellent configuration, black-to-white contrast and black quality, and various methods are disclosed (for example, see Patent Documents 1 to 5).

As a result of examining the techniques disclosed in each of the above-mentioned patent documents in detail, the inventor has found that display unevenness due to volatilization of the solvent occurs in long-term use. As a means for solving the problem, a method of solidifying the electrolyte is disclosed (for example, see Patent Document 6). However, when the electrolyte is solidified, it is found that there is a problem that the display speed is greatly reduced. It was. On the other hand, from the viewpoint of preventing volatilization of the solvent, there is a method using a plasticizer for plastics such as a phthalate ester having a low vapor pressure, but such a plasticizer is a suitable compound as a solvent with little volatilization. As a result, it was found that the display has a serious drawback such as a slow display speed and a low ability to dissolve the additive.
WO2004 / 068231 Specification WO 2004/066773 specification U.S. Pat. No. 4,240,716 Japanese Patent No. 3428603 JP 2003-241227 A JP 2006-146252 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a display element that has a high display speed, is excellent in durability even when repeatedly driven, and can maintain stable characteristics for a long period of time. .

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

  1. A display element comprising an electrolyte containing a compound represented by the following general formula (1) between opposing electrodes.

[Wherein, R _B1 represents an alkyl group, an aryl group, an amino group, an alkoxy group or an aryloxy group, and R _B2 and R _B3 each represents an alkyl group. ]
2. 2. The display according to 1 above, wherein R _{B1 to} R _B3 in the general formula (1) are all alkyl groups, and the total number of carbon atoms of R _{B1 to} R _B3 is 12 or more and 20 or less. element.

  3. 3. The display element according to 1 or 2 above, wherein the electrolyte contains silver or a compound containing silver in a chemical structure, and the counter electrode is driven so as to cause dissolution and precipitation of silver. .

  4). 4. The display element according to 3 above, wherein the compound containing silver in the chemical structure is a compound represented by the following general formula (2) or (3).

General formula (2)
R ₁ —SO ₃ —Ag
General formula (3)
R ₂ —CO ₂ —Ag
[Wherein, R ₁ and R ₂ each represents an electron-withdrawing group, and represents a substituent having a Hammett's substituent constant σ _m of +0.2 or more. ]
5). The display element according to 4 above, wherein the substituent R ₁ in the general formula (2) is represented by the following general formula (4) or (5).

[Wherein, n represents an integer of 0 or more, and R _{3 to} R ₁₀ are each a substituent satisfying the condition as R ₁ in the general formula (2). Note that * indicates a binding position. ]
6). 5. The display element according to 4 above, wherein the substituent R ₂ in the general formula (3) is represented by the following general formula (4) or (5).

[Wherein, n represents an integer of 0 or more, and R _{3 to} R ₁₀ are each a substituent satisfying the condition as R ₂ in the general formula (3). Note that * indicates a binding position. ]
7). The display element according to any one of 1 to 6, wherein the electrolyte contains a compound represented by the following general formula (6).

General formula (6)
^{_{P + R 11 R 12 R 13}} R 14 · X -
[Wherein R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ each represents an alkyl group, an aryl group, a heterocyclic group or an aralkyl group, and may be the same or different. X ⁻ represents an anion. ]
8). 8. The display element according to any one of 1 to 7, wherein the electrolyte contains a mercapto compound or a thioether compound.

  9. 9. The display element according to 8, wherein the mercapto compound is a compound represented by the following general formula (7).

[Wherein, M represents a hydrogen atom, a metal atom or quaternary ammonium, and Z represents a nitrogen-containing heterocyclic ring. n represents an integer of 0 to 5, and R ¹ 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 ¹ May be the same or different and may be linked to each other to form a condensed ring. ]
10. 9. The display device according to 8 above, wherein the thioether compound is a compound represented by the following general formula (8).

General formula (8)
R ² -S-R ³
[Wherein, R ² and R ³ each represent an alkyl group, an aryl group or a heterocyclic group, and may be the same or different, and may be linked to each other to form a ring. ]
11. 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] ( 11. The display element according to any one of 1 to 10 above, wherein a condition defined by the following formula (1) is satisfied when the mole / kg) is satisfied.

Formula (1) 0 ≦ [X] / [Ag] ≦ 0.01
12 12. The display element according to any one of 1 to 11, wherein the electrolyte is formed on one electrode of the counter electrode by a screen printing method.

  According to the present invention, it has been possible to provide a display element that has a high display speed, has excellent durability even when repeatedly driven, and can maintain stable characteristics for a long period of time.

  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, as a result of a display element comprising an amide compound represented by the general formula (1) as an electrolyte solvent between the counter electrodes, High display speed, excellent durability even after repeated driving, and suppression of solvent volatilization when used over a long period of time can improve display unevenness and realize a display element that can maintain stable characteristics over a long period of time. It is up to the headline and the present invention.

  The display element of the present invention further includes an electrolyte containing silver or a compound containing silver in the chemical structure and a compound represented by the general formula (1) between the counter electrodes, A display element that drives the counter electrode so as to cause precipitation is preferable.

  Details of the present invention will be described below.

〔Electrolytes〕
The term “electrolyte” as used in the present invention generally refers to a substance that dissolves in a solvent such as water and exhibits a ionic conductivity in the solution (hereinafter, referred to as “electrolyte in a narrow sense”). As a narrowly defined electrolyte, a mixture containing other metals, compounds, etc., regardless of whether it is an electrolyte or a non-electrolyte, is referred to as an electrolyte (“broadly defined electrolyte”).

  In addition to the compound represented by the general formula (1) according to the present invention, the electrolyte present between the counter electrodes according to the present invention includes an organic solvent, an ionic liquid, a redox active substance, a supporting electrolyte, a complexing agent, A white scatterer, a polymer binder, and the like are selected as necessary.

  Hereinafter, each component of the electrolyte according to the present invention will be further described.

(Compound represented by the general formula (1))
In the general formula (1), R _B1 represents an alkyl group, an aryl group, an amino group, an alkoxy group or an aryloxy group, and R _B2 and R _B3 each represents an alkyl group.

Examples of the alkyl groups represented by R _B1 , R _B2 and R _B3 include, for example, methyl group, ethyl group, propyl group, isopropyl group, t-butyl group, pentyl group, cyclopentyl group, hexyl group, cyclohexyl group, octyl group. Group, dodecyl group, etc., and the aryl group represented by R _B1 includes, for example, phenyl group, naphthyl group, etc., and the amino group includes, for example, amino group, ethylamino group, dimethylamino group, Examples include a butylamino group, a cyclopentylamino group, a 2-ethylhexylamino group, a dodecylamino group, an anilino group, a naphthylamino group, a 2-pyridylamino group, and the alkoxy group includes, for example, a methoxy group, an ethoxy group, and a propyloxy group. , Pentyloxy group, cyclopentyloxy group, hexyloxy group, cyclohexyloxy Group, octyloxy group, and dodecyloxy group. Examples of the aryloxy group include a phenoxy group, naphthyloxy group and the like.

In the present invention, R _B1 is preferably an alkyl group, an aryl group or an amino group, and R _{B1 to} R _B3 are all alkyl groups, and the total number of carbon atoms of R _{B1 to} R _B3 is It is preferable that they are 12 or more and 20 or less.

  As the compound containing silver or silver in combination with the compound represented by the general formula (1) according to the present invention in the chemical structure, compounds represented by the general formulas (2) to (5) of the present invention are preferable. Since the compounds represented by the general formulas (2) to (5) of the present invention have an electron-withdrawing group as a substituent, they have a high diffusion rate and a high reaction rate of silver ions. When the compound represented by the general formula (1) according to the present invention is used as an electrolyte solvent, the effect of improving the display speed is further increased.

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

  In addition to the above specific examples, specific examples of the compound represented by the general formula (1) according to the present invention include Exemplified Compound C- described in pages 8 to 10 of JP-A-5-188547. II-C-XVI, C-XVIII-C-XX, etc. can be mentioned.

(Organic solvent)
In the electrolyte according to the present invention, an amide compound represented by the general formula (1) is used as an organic solvent. However, other organic solvents may be used in combination as long as the object and effects of the present invention are not impaired. May be. The organic solvent that can be used in combination with the compound represented by the general formula (1) is an organic solvent having a boiling point in the range of 120 to 300 ° C. that can remain in the electrolyte without causing volatilization after the electrolyte is formed. For example, propylene carbonate, ethylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, butylene carbonate, γ-butyl lactone, tetramethyl urea, sulfolane, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone, 2- (N-methyl) -2-pyrrolidinone, hexamethylphosphortriamide, N-methylpropionamide, N, N-dimethylacetamide, N-methylacetamide, N, N dimethylformamide, N-methylformamide, butyronitrile, propiyl Nitrile, acetonitrile, acetylacetone, 4-methyl-2-pentanone, 2-butanol, 1-butanol, 2-propanol, 1-propanol, acetic anhydride, ethyl acetate, ethyl propionate, dimethoxyethane, diethoxyfuran, tetrahydrofuran, ethylene Examples include glycol, diethylene glycol, triethylene glycol monobutyl ether, tricresyl phosphate, 2-ethylhexyl phosphate, dioctyl phthalate, and dioctyl sebacate.

  Among the organic solvents, it is preferable to use cyclic carboxylic acid ester compounds such as propylene carbonate, ethylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, butylene carbonate, and γ-butyl lactone.

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

(Ionic liquid)
An ionic liquid can be added to the electrolyte according to the present invention. The ionic liquid referred to in the present invention refers to a salt that exists in a liquid state even at room temperature, and can be selected from, for example, a combination of a cation such as imidazolium or pyridinium and an anion such as fluoride ion or triflate.

(Polymer binder)
As a polymer binder applicable to the electrolyte according to the present invention, from the viewpoint of the characteristics of the display element and the viscosity of the electrolyte, for example, from various polymer compounds such as butyral resin, polyvinyl alcohol, polyethylene glycol, and polyvinylidene fluoride. In the present invention, it is preferable to use a butyral resin as the polymer binder. In the present invention, after adding a butyral resin to an organic solvent, it can be heated and dissolved, and the mass ratio of the organic solvent to the butyral resin is preferably in the range of 10: 1 to 2: 1. A preferred range is 10: 1 to 10: 3.

  Specific examples of the butyral resin applicable to the electrolyte according to the present invention include, for example, # 3000-1, # 3000-2, # 3000-4, # 3000-K, # 4000-2 manufactured by Denki Kagaku Kogyo Co., Ltd. , # 5000-A, # 5000-D, # 6000-C, # 6000-AS, # 6000-CS, Sreck series manufactured by Sekisui Chemical Co., Ltd., and the like.

(Spacer)
In the display element of the present invention, a spacer can be added to the electrolyte. The spacer in the present invention is a fine particle for controlling the gap between the counter electrodes, and for example, a microsphere made of glass, acrylic resin, silica, or the like used for a liquid crystal display or the like is used. Can do. The average particle diameter is preferably in the range of 10 μm or more and 50 μm or less from the viewpoint of dispersion stability in the electrolyte, screen printing suitability, or display element characteristics.

(White scattered matter)
A white scatterer can be applied to the electrolysis according to the present invention. The white scattering material referred to in the present invention is any material that can adjust the display color by adding it to the electrolyte, preferably an inorganic material, more preferably a metal oxide. Examples of the metal oxide 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 salts, talc, kaolin, zeolite, acidic clay, glass and the like can be mentioned.

  In addition, as organic compounds, polyethylene, polystyrene, acrylic resin, ionomer, ethylene-vinyl acetate copolymer resin, benzoguanamine resin, urea-formalin resin, melamine-formalin resin, polyamide resin, etc. are used alone or in a composite mixture, or in particles You may use it in the state which has the void which changes a refractive index.

In the present invention, among the coloring materials, titanium dioxide, zinc oxide, and zinc hydroxide are preferably used. In particular, titanium dioxide is used from the viewpoint of preventing coloring at high temperatures and reflectivity of the element due to refractive index. Is more preferable. Moreover, titanium dioxide is preferably titanium dioxide surface treated with an inorganic oxide (Al ₂ O ₃ or SiO _2).

  The white scattering material according to the present invention is added to the mixture of the organic solvent and butyral resin constituting the electrolyte according to the present invention, and is dispersed in the electrolyte using a wet pulverizing disperser such as an ultrasonic disperser or a bead mill. Can be used.

  In the present invention, the mass ratio of the organic solvent to the coloring material is preferably in the range of 10: 1 to 1: 1, more preferably 5: 1 to 5: 4.

  The white scattering material according to the present invention is preferably added after the butyral resin is dissolved in an organic solvent or an ionic liquid.

  In the display element of the present invention, a porous layer containing a white scattering material (hereinafter referred to as a porous white scattering layer) may be formed between the counter electrodes. The porous white scattering layer can be formed by applying a white scatterer, a dispersion solvent, a dispersion containing a fluorescent brightening agent and a polymer compound by a coating method, an inkjet method, a printing method, or the like. A preferred method of forming the porous white scattering layer is a screen printing method.

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

  Porous as used in the present invention means that after forming a porous white scatterer, an electrolyte solution containing silver or a compound containing silver in the chemical structure is provided on the scatterer, and then sandwiched between counter electrodes. This refers to a penetrating state in which a potential difference can be applied between opposing electrodes to cause a dissolution and precipitation reaction of silver, and ion species can move between the electrodes.

(Silver or a compound containing silver in the chemical structure)
Examples of the compound containing silver or silver contained in the electrolyte according to the present invention in the chemical structure include compounds such as silver oxide, silver sulfide, metallic silver, silver colloidal particles, silver halide, silver complex compounds, and silver ions. There are no particular restrictions on the phase state species such as the solid state, the solubilized state in liquid, and the gas state, and the charged state species such as neutral, anionic, and cationic.

  The 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.

(Compound represented by general formula (2) or general formula (3))
In the present invention, the compound containing silver in the chemical structure is preferably a compound represented by the following general formula (2) or (3).

General formula (2)
R ₁ —SO ₃ —Ag
General formula (3)
R ₂ —CO ₂ —Ag
In the formula, each of R ₁ and R ₂ represents an electron-withdrawing group, and represents a substituent having Hammett's substituent constant σ _m of +0.2 or more. More preferred is a substituent having a Hammett's substituent constant σ _m of +0.3 or more.

The Hammett substituent constant σ _m in the present invention refers to a numerical value representing the effect of the substituent on the acid dissociation equilibrium constant of the substituted benzoic acid.

Examples of the substituent represented by R ₁ and R ₂ that satisfy the conditions of the present invention include CBr ₃ , CCl ₃ , CF ₃ , CN, CHO, CONH ₂ , C═CH, CH ₂ SO ₂ CF ₃ , COCH. ₃ , CO ₂ CH ₃ , C═O (NHCH ₃ ), C═S (NHCH ₃ ), CF (CF ₃ ) ₂ , C (OH) (CF ₃ ) ₂ , CH═CHCN, CH═CHCHO, CO ₂ C ₂ H ₅ , CF ₂ CF ₂ CF ₂ CF ₃ , CH═CHCOCH ₃ , C ₆ Cl ₅ , C ₆ CF ₅ , OCF ₃ , OCHF ₂ , OSO ₂ CH ₃ , OCF ₂ CHFCl, OCOCH ₃ , OC ₆ H ₅ , OSO ₂ C ₆ H ₅ , POCl ₂ , PCl ₂ , POF ₂ , PF ₂ , PSCl ₂ , P (Cl) N (CH ₃ ) ₂ , PO (CH ₃ ) ₂ , PO (OCH ₃ ) ₂ , PO (C ₂ H ₅ ) ₂ , OCF ₂ CF ₂ H, 2-C ₅ H ₄ N, OSO ₂ CF ₃ , C (CF ₃ ) ₃ , pyrrole, CH═C (CN) ₂ , COOC ₆ H ₅ , C (OC) (CF ₃ ) _{2 and the} like.

  Typical specific examples of the compound represented by the general formula (2) are shown below.

  Of the compounds represented by the general formula (2) exemplified above, a particularly preferred compound is the exemplified compound (2-1).

  Next, typical specific examples of the compound represented by the general formula (3) are shown below.

  Of the compounds represented by the general formula (3) exemplified above, a particularly preferred compound is the exemplified compound (3-1).

In the general formula (2), the substituent R ₁ is preferably represented by the general formula (4) or (5). In the general formula (3), the substituent R ₂ is represented by the general formula (4). ) Or (5).

In the general formulas (4) and (5), n represents an integer of 0 or more, and R _{3 to} R ₁₀ satisfy the conditions as R ₁ and R ₂ in the general formulas (2) and (3), respectively. It is a substituent. Note that * indicates a binding position.

  Typical specific examples of the compound represented by the general formula (4) are shown below.

  Of the compounds represented by the general formula (4) exemplified above, particularly preferred compounds are the exemplified compounds (4-1), (4-2), (4-5), and (4-6).

  Next, typical specific examples of the compound represented by the general formula (5) are shown below.

  Among the compounds represented by the general formula (5) exemplified above, particularly preferred compounds are the exemplified compounds (5-1), (5-2), (5-5) and (5-6).

(Compound represented by the general formula (6))
In the electrolyte which concerns on this invention, it is preferable to contain the spiro ammonium compound represented by the said General formula (6).

General formula (6)
^{_{P + R 11 R 12 R 13}} R 14 · X -
In the general formula (6), R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ each represents an alkyl group, an aryl group, a heterocyclic group or an aralkyl group, and may be the same or different. X ⁻ represents an anion.

R _{11 to} R ₁₄ are each independently hydrogen, a saturated or unsaturated alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aryl group having 6 to 10 carbon atoms, or 7 to 7 carbon atoms. 11 aralkyl group, R ₁₅ —X— (R ₁₆ —Y—) _n — (wherein R ₁₅ is an alkyl group having 4 or less carbon atoms, R ₁₆ is an alkylene group having 4 or less carbon atoms, and X and Y are oxygen atoms) An atom or a sulfur atom, and n represents an integer of 0 to 10), and these groups may have a substituent.

Specific examples of R _{11 to} R _{14 in} the above are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, A linear or branched alkyl group such as nonyl and decyl; a cycloalkyl group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl; unsubstituted or halogen atom (eg, F, Cl, Br, I ), Hydroxyl group, lower alkoxy group (eg, methoxy, ethoxy, propoxy, butoxy, etc.), carboxyl group, acetyl group, propanoyl group, thiol group, lower alkylthio group (eg, methylthio, ethylthio, propylthio, butylthio, etc.) Each group), amino group, lower alkylamino Groups, aryl groups such as phenyl, naphthyl, toluyl and xylyl having 1 to 3 substituents such as a di-lower alkylamino group, and aralkyl groups such as benzyl.

Further, specific examples of R ₁₅ include methyl, ethyl, n- propyl, isopropyl, n- butyl, isobutyl, sec- butyl, and alkyl groups such as t- butyl and the like, methylene as R _16, Examples thereof include alkylene groups such as ethylene, propylene, and butylene.

X ^- is the anion species represented by may be any compound as long as the anion. Specific examples include (FSO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , CH ₃ SO ₄ ⁻ , Br ⁻ , Cl ⁻ , OH ⁻ , NO ₃ ⁻ , PF ₆ ⁻ , BF ₄ ⁻ , CH ₃ —Ph—SO ₃ ⁻ , CF ₃ SO ₃ ⁻ , C ₈ F ₁₇ SO ₃ ⁻ , C ₄ H ₉ SO ₃ ⁻ , CH ₃ OSO ₃ ⁻ , C ₈ H ₁₇ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , HSCN ⁻ , CH ₃ COO ⁻ , C ₈ H ₁₇ COO ⁻ , (CN) ₂ N ⁻ .

(Mercapto compounds, thioether compounds)
The electrolyte according to the present invention preferably contains a mercapto compound or a thioether compound together with the above-described coloring material, butyral resin, and organic solvent. Further, the mercapto compound contains the general formula (7). It is preferable that it is a compound represented by these, or that a thioether type compound is a compound represented by the said General formula (8).

<Compound represented by formula (7)>
In the general formula (7), M represents a hydrogen atom, a metal atom, or quaternary ammonium. Z represents a nitrogen-containing heterocyclic ring excluding imidazole rings. n represents an integer of 0 to 5, and R ¹ 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 ¹ 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 (7) include Li, Na, K, Mg, Ca, Zn, and Ag. Examples of the quaternary ammonium include NH ₄ , N (CH ₃ ) ₄ , N (C ₄ H ₉ ) ₄ , N (CH ₃ ) ₃ C ₁₂ H ₂₅ , N (CH ₃ ) ₃ C ₁₆ H ₃₃ , N (CH ₃ ) ₃ CH ₂ C ₆ H _{5 and the} like It is done.

  Examples of the nitrogen-containing heterocycle represented by Z in the general formula (7) include tetrazole ring, triazole ring, oxadiazole ring, thiadiazole ring, indole ring, oxazole ring, benzoxazole ring, benzothiazole ring, benzoselena Examples thereof include a sol ring and a naphthoxazole ring.

Examples of the halogen atom represented by R ¹ in the general formula (7) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group include methyl, ethyl, propyl, i- Examples include propyl, butyl, t-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, octyl, dodecyl, hydroxyethyl, methoxyethyl, trifluoromethyl, benzyl, etc. Examples of the aryl group include phenyl, naphthyl and the like. Examples of the alkylcarbonamide group include acetylamino, propionylamino, butyroylamino and the like. Examples of the arylcarbonamide group include benzoylamino and the like. Examples of the sulfonamide group include methanesulfonyl. Minosulfonyl, ethanesulfonylamino group and the like, arylsulfonamide groups include, for example, benzenesulfonylamino group, toluenesulfonylamino group and the like, and aryloxy groups include, for example, phenoxy and the like, alkylthio Examples of the group include each group such as methylthio, ethylthio, and butylthio. Examples of the arylthio group include phenylthio group and tolylthio group. Examples of the alkylcarbamoyl group include methylcarbamoyl, dimethylcarbamoyl, Examples include ethyl carbamoyl, diethyl carbamoyl, dibutyl carbamoyl, piperidyl carbamoyl, morpholyl carbamoyl and the like, and aryl carbamoyl groups include, for example, phenyl carbamoyl, methyl phenyl carbamoyl Examples include groups such as vamoyl, ethylphenylcarbamoyl, and benzylphenylcarbamoyl. Examples of the alkylsulfamoyl group include methylsulfamoyl, dimethylsulfamoyl, ethylsulfamoyl, diethylsulfamoyl, and dibutylsulfamoyl. Examples of each group include moyl, piperidylsulfamoyl, morpholylsulfamoyl, and arylsulfamoyl groups include, for example, phenylsulfamoyl, methylphenylsulfamoyl, ethylphenylsulfamoyl, benzylphenylsulfamoyl. Examples of the alkylsulfonyl group include a methanesulfonyl group and an ethanesulfonyl group. Examples of the arylsulfonyl group include phenylsulfonyl and 4-chlorophenylsulfonyl. Examples of each group include p-toluenesulfonyl and the like. Examples of the alkoxycarbonyl group include groups such as methoxycarbonyl, ethoxycarbonyl and butoxycarbonyl. Examples of the aryloxycarbonyl group include phenoxycarbonyl and the like. Examples of the alkylcarbonyl group include acetyl, propionyl, butyroyl, and the like. Examples of the arylcarbonyl group include a benzoyl group and an alkylbenzoyl group. Examples of the acyloxy group include acetyloxy. , Propionyloxy, butyroyloxy and the like, and examples of the heterocyclic group include oxazole ring, thiazole ring, triazole ring, selenazole ring, tetrazole ring, oxadiazole ring, thiadiazole ring, thiazol ring, and the like. Down ring, a triazine ring, a benzoxazole ring, benzothiazole ring, an indolenine ring, benzimidazole benzoselenazole ring, naphthothiazole ring, triazaindolizine ring, diaza indolizine ring, tetraazacyclododecane indolizine ring group, and the like. These substituents further include those having a substituent.

  Next, although the preferable specific example of a compound represented by General formula (7) is shown, this invention is not necessarily limited to these compounds.

<Compound represented by formula (8)>
In the general formula (8), R ² and R ³ each represents an alkyl group, an aryl group or a heterocyclic group, and may be the same or different, and may be linked to each other to form a ring. Also good.

Examples of the alkyl group represented by R ² and R ³ in the general formula (8) include methyl, ethyl, propyl, i-propyl, butyl, t-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, octyl, and dodecyl. , Hydroxyethyl, methoxyethyl, trifluoromethyl, benzyl, and the like. Examples of the aryl group include a phenyl group and a naphthyl group. Examples of the heterocyclic group include an oxazole ring and an imidazole ring. , Thiazole ring, triazole ring, selenazole ring, tetrazole ring, oxadiazole ring, thiadiazole ring, thiazine ring, triazine ring, benzoxazole ring, benzthiazole ring, benzimidazole ring, indolenine ring, benzselenazole ring, naphthothiazole Ring, Triazaindori Down ring, diaza indolizine ring, tetraazacyclododecane indolizine ring group, and the like. These substituents further include those having a substituent.

  Next, although the preferable specific example of a compound represented by General formula (8) is shown, this invention is not necessarily limited to these compounds.

(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
The halogen atom as used in the field of this invention means an iodine atom, a chlorine atom, a bromine atom, and a fluorine atom. When [X] / [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 blackened silver to dissolve the blackened silver. Therefore, the molar concentration of halogen atoms is preferably as low as possible relative to the molar concentration of silver. 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.

[Configuration of display element]
In the display element of the present invention, various constituent layers can be provided as necessary in addition to the electrolyte described above. For example, a layer containing a compound exhibiting electrochromic properties may be formed on the counter electrode, so that an element structure capable of color display can be taken.

  In the display element of the present invention, the display portion is provided with one corresponding counter electrode. The electrode 1 that is one of the counter electrodes (display side electrodes) close to the display unit is provided with a transparent electrode such as an ITO electrode, and the other electrode 2 (non-display side electrode) is provided with a metal electrode such as a silver electrode. Yes. 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 counter electrodes, the electrode 1 and the electrode 2 are supported. A silver oxidation-reduction reaction is performed on the top, so that a black silver image in a reduced state and a transparent silver state in an oxidized state can be switched reversibly.

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

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

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

(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 agent, hardener, surfactant, thickener, plasticizer, slip agent, UV absorber, irradiation prevention dye, filter light absorbing dye, culture medium, polymer latex, heavy metal, antistatic agent, matting agent Etc. can be contained as required.

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

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

Additive RD17643 RD18716 RD308119
Page Classification Page Classification Page Classification Chemical sensitizer 23 III 648 Upper right 96 III
Sensitizing dye 23 IV 648-649 996-8 IV
Desensitizing dye 23 IV 998 IV
Dye 25-26 VIII 649-650 1003 VIII
Development accelerator 29 XXI 648 Upper right Anti-fogging agent / stabilizer
24 IV 649 Upper right 1006-7 VI
Brightener 24 V 998 V
Hardener 26 X 651 Left 1004-5 X
Surfactant 26-7 XI 650 Right 1005-6 XI
Antistatic agent 27 XII 650 Right 1006-7 XIII
Plasticizer 27 XII 650 Right 1006 XII
Slipper 27 XII
Matting agent 28 XVI 650 Right 1008-9 XVI
Binder 26 XXII 1003-4 IX
Support 28 XVII 1009 XVII
(substrate)
Examples of the substrate that can be used in the present invention include polyolefins such as polyethylene and polypropylene, polycarbonates, cellulose acetate, polyethylene terephthalate, polyethylene dinaphthalene dicarboxylate, polyethylene naphthalates, polyvinyl chloride, polyimide, and polyvinyl acetal. Synthetic plastic films such as polystyrene can also be preferably used. Syndiotactic polystyrenes are also preferred. These can be obtained, for example, by the methods described in JP-A Nos. 62-117708, 1-46912 and 1-178505. Further, a metal substrate such as stainless steel, a paper support such as baryta paper and resin coated paper, and a support provided with a reflective layer on the plastic film, supported by JP-A-62-253195 (pages 29-31) The thing described as a body is mentioned. RDNo. 17643, page 28, ibid. No. 18716, page 647, right column to page 648, left column, and No. 307105, page 879 can also be preferably used. As these supports, those having resistance to curling due to heat treatment of Tg or less as in US Pat. No. 4,141,735 can be used. Further, the surface of these supports may be subjected to surface treatment for the purpose of improving the adhesion between the support and other constituent layers. In the present invention, glow discharge treatment, ultraviolet irradiation treatment, corona treatment, and flame treatment can be used as the surface treatment. Furthermore, the support body described in pages 44 to 149 of publicly known technology No. 5 (issued by Aztec Co., Ltd. on March 22, 1991) can also be used. Furthermore, RDNo. 308119, page 1009, Product Licensing Index, Volume 92, P108, “Supports”, and the like. In addition, a glass substrate or an epoxy resin kneaded with glass can be used.

(electrode)
In the display element of the present invention, it is preferable that at least one of the counter electrodes is a metal electrode. As the metal electrode, for example, a known metal species such as platinum, gold, palladium, silver, copper, aluminum, zinc, nickel, titanium, bismuth, and alloys thereof can be used.

  In the present invention, the metal electrode may take a configuration composed of two or more layers as required. The outermost surface of the metal electrode is preferably formed of a metal having a smaller ionization tendency than the metal contained in the polymer film from the viewpoint of electrode durability.

  As an electrode manufacturing method, an existing method such as an electrolytic plating method, an electroless plating method, a displacement plating method, a vapor deposition method, a printing method, an ink jet method, a spin coating method, or a CVD method can be used.

  In the display element of the present invention, it is preferable that at least one of the counter electrodes is a transparent electrode. The transparent electrode is not particularly limited as long as it is transparent and conducts electricity. For example, Indium Tin Oxide (ITO: Indium Tin Oxide), Indium Zinc Oxide (IZO: Indium Zinc Oxide), Fluorine Doped Tin Oxide (FTO), Indium Oxide, Zinc Oxide, Platinum, Gold, Silver, Rhodium, Copper, Examples thereof include chromium, carbon, aluminum, silicon, amorphous silicon, and BSO (Bismuth Silicon Oxide). In order to form the electrode in this manner, for example, an ITO film may be vapor-deposited on the substrate by a sputtering method or the like, or an ITO film may be formed on the entire surface and then patterned by a photolithography method. The surface resistance value is preferably 100Ω / □ or less, and more preferably 10Ω / □ or less. The thickness of the transparent electrode is not particularly limited, but is generally 0.1 to 20 μm.

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

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

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

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

(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 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 a pair of substrates are overlapped with the electrode formation surfaces facing each other to form an empty cell. To do. 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, when the substrates are bonded together, the electrolyte composition may be dropped on one substrate, and the liquid crystal composition may be sealed simultaneously with the bonding of the substrates.

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

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

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to these. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

<< Preparation of electrolyte solution >>
(Preparation of electrolyte solution 1)
In 2.5 g of dimethyl sulfoxide (DMSO), 100 mg of silver iodide (AgI) and 200 mg of mercaptobenzimidazole (MBIZ) were added and dissolved by heating, and then the titanium dioxide CR-90 manufactured by Ishihara Sangyo Co., Ltd. was used. Was mixed to obtain an electrolyte solution 1.

(Preparation of electrolyte solution 2)
Electrolyte solution 2 was obtained in the same manner as in the preparation of electrolyte solution 1 except that dimethyl sulfoxide (DMSO) was changed to chloroform and titanium dioxide CR-90 was removed.

(Preparation of electrolyte solution 3)
In a mixed solution of 1.0 g of γ-butyrolactone (γBL) and 1.5 g of Exemplified Compound 1-1, 100 mg of silver p-toluenesulfonate (silver salt compound 1) and 200 mg of Exemplified Compound 7-12 In addition, 1.2 g of titanium dioxide CR-90 manufactured by Ishihara Sangyo Co., Ltd. was mixed with the liquid obtained by heating and dissolving to obtain an electrolyte solution 3.

(Preparation of electrolyte solution 4)
In 2.5 g of Exemplified Compound 1-1, 100 mg of Silver Salt Compound 1 and 200 mg of Exemplified Compound 7-12 were added and dissolved by heating. To a solution obtained by heating, titanium dioxide CR-90 manufactured by Ishihara Sangyo Co., Ltd. was added. 1.2g was mixed and the electrolyte solution 4 was obtained.

(Preparation of electrolyte solution 5)
In 2.5 g of Exemplified Compound 1-1, 100 mg of Silver Salt Compound 1, 100 mg of Exemplified Compound 7-12, and 100 mg of Exemplified Compound 7-18 were added and dissolved in a solution obtained by heating. An electrolyte solution 4 was obtained by mixing 1.2 g of titanium dioxide CR-90 manufactured by the company.

(Preparation of electrolyte solution 6)
The electrolyte solution 6 was obtained in the same manner as in the preparation of the electrolyte solution 4 except that the exemplified compound 7-12 was changed to the exemplified compound 8-1.

(Preparation of electrolyte solution 7)
In 2.5 g of Example Compound 1-1, 100 mg of Silver Salt Compound 1, 100 mg of Example Compound 7-12, 100 mg of Example Compound 7-18, and 15 mg of Example Compound 6-1 are added and dissolved by heating. The electrolyte solution 7 was obtained by mixing 1.2 g of titanium dioxide CR-90 manufactured by Ishihara Sangyo Co., Ltd.

(Preparation of electrolyte solutions 8-12)
In the preparation of the electrolyte solutions 3 to 7, electrolyte solutions 8 to 12 were obtained in the same manner except that the silver salt compound 1 was changed to the exemplary compound 4-2.

(Preparation of electrolyte solution 13)
An electrolyte solution 13 was obtained in the same manner as in the preparation of the electrolyte solution 12 except that the exemplified compound 1-1 was changed to the exemplified compound 1-2.

(Preparation of electrolyte solution 14)
In the preparation of the electrolyte solution 12, the electrolyte solution was changed in the same manner except that the exemplified compound 4-2 was changed to the exemplified compound 2-1 as the silver salt compound, and the exemplified compound 1-1 was changed to the exemplified compound 1-3. 14 was obtained.

(Preparation of electrolyte solution 15)
An electrolyte solution 15 was obtained in the same manner as in the preparation of the electrolyte solution 12 except that the exemplified compound 1-1 was changed to the exemplified compound 1-9.

(Preparation of electrolyte solution 16)
An electrolyte solution 16 was obtained in the same manner as in the preparation of the electrolyte solution 12 except that the exemplified compound 1-1 was changed to the exemplified compound 1-10.

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

(Preparation of electrode 2)
A silver-palladium electrode (electrode 2) having an electrode thickness of 0.8 μm, a pitch of 145 μm, and an electrode interval of 130 μm is formed on a glass substrate having a thickness of 1.5 mm and a size of 10 cm × 10 cm by using a known method. Got.

<< Production of display element >>
(Preparation of display element 1)
A glass spherical bead-shaped spacer having an average particle diameter of 40 μm on the periphery of the electrode 2 bordered with an olefin-based sealant containing a glass spherical bead-shaped spacer having an average particle diameter of 40 μm as a volume fraction of 10%. After spraying, electrode 2 and electrode 1 were bonded together and heated and pressed to produce an empty cell. The electrolyte solution 1 was vacuum-injected into the empty cell, and the injection port was sealed with an epoxy-based ultraviolet curable resin to produce a display element 1.

(Preparation of display element 2)
Titanium dioxide paste obtained by mixing and dispersing titanium dioxide and polyvinyl alcohol in pure water was applied onto electrode 2 to a dry film thickness of 40 μm by blade coating, and the water was completely evaporated at 120 ° C. A white scattering layer was formed. Next, the obtained electrode 2 with a porous white scattering layer is immersed in the electrolyte solution 2 and, after confirming that the electrolyte solution 2 has sufficiently penetrated into the porous white scattering layer, the electrode 2 is taken out from the electrolyte solution 2. The chloroform was completely evaporated at 80 ° C. to solidify the electrolyte. Next, the periphery of the electrode 2 is trimmed with an olefin-based sealant containing a glass spherical bead spacer having an average particle diameter of 40 μm as a volume fraction of 10%, and then the electrode 2 and the electrode 1 are bonded together and heated. The display element 2 was produced by pressing.

(Production of display elements 3 to 16)
In the production of the display element 1, display elements 3 to 16 were produced in the same manner except that the electrolyte solutions 3 to 16 were used instead of the electrolyte solution 1.

<< Evaluation of display element >>
(Evaluation of display speed)
Of each display device produced in the above, the reflectance of a white 550nm when not driven was measured by the spectral colorimeter CM-3700d manufactured by Konica Minolta Sensing, Inc., the reflectance measured, thereby providing an R _W . Next, after applying a voltage of 1.5 V for 1.5 seconds, a voltage of -1.5 V was applied for 0.5 seconds to display gray, and the reflectance at 550 nm was measured and obtained in the same manner. The reflectance was R _G. The R _W a difference R _G and R _S, was used as an indicator of the display speed R _S. Here, it is assumed that the display speed is faster as R _S is higher.

(Evaluation of display unevenness resistance)
Each display element produced above is stored for 20 days in an environment of 85 ° C., and then a white voltage is displayed by applying a voltage of 1.5 V for 1.5 seconds until the reflectance at 500 nm reaches about 30%. .5V voltage is applied, gray is displayed, and the reflectance at 550 nm at any five locations of the display element is measured with a spectrocolorimeter CM-3700d manufactured by Konica Minolta Sensing Co., Ltd. The difference between the minimum values was calculated. The calculated difference in reflectance was ΔR _Glay, and R _Glay was used as an indicator of display speed. Here, the smaller ΔR _Glay is, the better the display unevenness resistance is.

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

  As is clear from the results shown in Table 1, by using the amide compound represented by the general formula (1) of the present invention as the solvent of the electrolyte, the solvent is volatilized over a long period of time without lowering the display speed. It can be seen that the display unevenness is improved. In particular, when the compound represented by the general formula (2) or (3) is used as the compound containing silver in the structure, it can be seen that the display unevenness is further improved and the display speed is improved.

Claims (12)

A display element comprising an electrolyte containing a compound represented by the following general formula (1) between opposing electrodes.

[Wherein, R _B1 represents an alkyl group, an aryl group, an amino group, an alkoxy group or an aryloxy group, and R _B2 and R _B3 each represents an alkyl group. ] R _{B1 to} R _B3 in the general formula (1) are all alkyl groups, and the total number of carbon atoms of R _{B1 to} R _B3 is 12 or more and 20 or less. The display element as described in.   3. The method according to claim 1 or 2, wherein the electrolyte contains silver or a compound containing silver in a chemical structure, and the counter electrode is driven so as to cause dissolution and precipitation of silver. The display element as described. The display element according to claim 3, wherein the compound containing silver in a chemical structure is a compound represented by the following general formula (2) or (3).
General formula (2)
R ₁ —SO ₃ —Ag
General formula (3)
R ₂ —CO ₂ —Ag
[Wherein, R ₁ and R ₂ each represents an electron-withdrawing group, and represents a substituent having a Hammett's substituent constant σ _m of +0.2 or more. ] The display element according to claim 4, wherein the substituent R ₁ in the general formula (2) is represented by the following general formula (4) or (5).

[Wherein, n represents an integer of 0 or more, and R _{3 to} R ₁₀ are each a substituent satisfying the condition as R ₁ in the general formula (2). Note that * indicates a binding position. ] The display device according to claim 4, wherein the substituent R ₂ in the general formula (3) is represented by the following general formula (4) or (5).

[Wherein, n represents an integer of 0 or more, and R _{3 to} R ₁₀ are each a substituent satisfying the condition as R ₂ in the general formula (3). Note that * indicates a binding position. ] The display element according to any one of claims 1 to 6, wherein the electrolyte contains a compound represented by the following general formula (6).
General formula (6)
^{_{P + R 11 R 12 R 13}} R 14 · X -
[Wherein R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ each represents an alkyl group, an aryl group, a heterocyclic group or an aralkyl group, and may be the same or different. X ⁻ represents an anion. ]   The display element according to any one of claims 1 to 7, wherein the electrolyte contains a mercapto compound or a thioether compound. The display element according to claim 8, wherein the mercapto compound is a compound represented by the following general formula (7).

[Wherein, M represents a hydrogen atom, a metal atom or quaternary ammonium, and Z represents a nitrogen-containing heterocyclic ring. n represents an integer of 0 to 5, and R ¹ 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 ¹ May be the same or different and may be linked to each other to form a condensed ring. ] The display device according to claim 8, wherein the thioether-based compound is a compound represented by the following general formula (8).
General formula (8)
R ² -S-R ³
[Wherein, R ² and R ³ each represent an alkyl group, an aryl group or a heterocyclic group, and may be the same or different, and may be linked to each other to form a ring. ] 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 10, wherein a condition defined by the following formula (1) is satisfied:
Formula (1) 0 ≦ [X] / [Ag] ≦ 0.01   The display element according to any one of claims 1 to 11, wherein the electrolyte is formed on one electrode of the counter electrode by a screen printing method.