JP2010204438A - Display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display element the driving voltage of which is low, which has a memory property, and is excellent in repetitive drive resistance. <P>SOLUTION: In the display element containing an electrochromic medium between at least a pair of opposing electrodes, the electrochromic medium contains an oxidation coloring type electrochromic compound, a compound indicated by the general formula (1), an electrolyte, and an oxidation reduction reaction type compound. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a display element that utilizes the coloring and decoloring of an electrochromic compound.

  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 conventionally provided in printed materials using paper has become easier. Opportunities for obtaining or browsing electronic information are increasing more and more.

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

  As a display means to compensate for these drawbacks, a reflection type display having a so-called memory property that uses external light and does not consume power for image retention is known. However, it 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 driving 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 these disadvantages of the above-mentioned methods, an electrochromic display element (hereinafter abbreviated as an EC method) using an electrochromic compound that exhibits color development and decoloration and dissolution precipitation of a metal or a metal salt are used. An electrochemical method such as an electrodeposition method (hereinafter abbreviated as ED method) is known. These systems have an advantage that they can be formed with a simple element configuration and can be driven at a low voltage of 3 V or less. In particular, the EC system is promising in that various color displays are possible by selecting an electrochromic compound.

  As an EC display device using such a compound, a composition used for electrochromic display capable of suppressing deterioration of display quality when repeatedly used over a long period of time and maintaining color development at low power is disclosed. (For example, refer to Patent Document 1). However, the composition disclosed individually in the cited document 1 is discolored immediately after the voltage application is cut off, and when trying to maintain the display for a long time, the composition is continuously It is necessary to continue to apply a low voltage. Also, the voltage applied for display is 3.5 volts, and it has become clear that driving with low power, which is known as a merit of the EC method, cannot be performed.

JP 2007-314721 A

  The present invention has been made in view of the above problems, and its purpose is that there is little deterioration in display quality even during repeated use over a long period of time, it can be driven at a low voltage, and has excellent memory properties. An object is to provide an electrochromic display element.

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

  1. In a display element containing an electrochromic medium between at least a pair of opposing electrodes, the electrochromic medium includes an oxidation coloring electrochromic compound, a compound represented by the following general formula (1), an electrolyte, and a redox reaction type A display element comprising a compound.

[Wherein M ₁ is an element belonging to Group 15 of the periodic table and does not contain nitrogen. R ₁ , R ₂ and R ₃ each represent an aryl group having a substituent or an aryl group having no substituent, and may be the same or different from each other. ]
2. 2. The display element according to 1 above, wherein the oxidative coloring electrochromic compound is a compound having a structure represented by the following general formula (A).

[Wherein, X represents a carbon atom or a nitrogen atom, and R ₄ and R ₅ each represents a substituted or unsubstituted aromatic group, a group having a substituted or unsubstituted heterocyclic ring, or a fluoran group. R ₄ and R ₅ may form part of the fluorane skeleton. R ₆ represents a hydrogen atom, a halogen atom, a substituted or unsubstituted acyl group, an alkyl group, an alkoxy group, a nitro group, an aryl group, or an amino group, respectively. ]
3. 3. The display element according to 1 or 2, wherein the electrochromic medium further contains a compound represented by the following general formula (2) or general formula (3).

[Wherein, R ₇ , R ₈ , R ₉ and R ₁₀ each represent a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group or an alkoxycarbonyl group. R ₇ , R ₈ , R ₉ and R ₁₀ are not all hydrogen atoms at the same time. Adjacent R ₇ and R ₈ may be condensed with each other to form a 5-membered or 6-membered condensed ring. Adjacent R ₉ and R ₁₀ may be condensed with each other to form a 5-membered or 6-membered condensed ring. ]

(In the formula, R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ each represent a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group or an alkoxycarbonyl group. R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ are all Are not simultaneously hydrogen atoms, either adjacent R ₁₁ and R ₁₂ , or adjacent R ₁₃ and R ₁₄ , one or both form a condensed ring, adjacent R ₁₁ and R ₁₂ , or When one of adjacent R ₁₃ and R ₁₄ forms a condensed ring, the other two groups are both hydrogen atoms, and the condensed ring is a 5-membered or 6-membered ring.]
4). 4. The display element according to any one of items 1 to 3, wherein the electrochromic medium contains an oxidation reaction type compound and a reduction reaction type compound as the oxidation reduction reaction type compound.

  5. The oxidation reaction type compound is an N-oxyl derivative, an N-hydroxyphthalimide derivative, a compound having an N—O bond of a hydroxamic acid derivative, or a compound having an allyloxy free group having a bulky substituent introduced at the O-position of galvinoxyl. 5. The display element as described in 4 above, which is at least one selected.

  6). The reduction reaction type compound is at least one selected from ethanedione or a derivative thereof, tetrazolium salt, formazan or a derivative thereof, phenazine or a derivative thereof, phenoxazine or a derivative thereof, and acridine or a derivative thereof. The display element as described in.

  7). 7. The display element according to any one of 1 to 6, wherein at least one electrode surface of the pair of opposed electrodes has a nanoporous layer.

  8). 8. The display element according to 7 above, wherein the nanoporous layer provided on the observation-side electrode surface among the nanoporous layers fixes the oxidation reaction type compound.

  9. 8. The display element according to 7 above, wherein the nanoporous layer provided on the non-observation-side electrode surface of the nanoporous layer immobilizes the reduction reaction type compound.

  10. 10. The display element according to any one of 1 to 9, wherein the electrochromic medium includes a white scatterer.

  According to the present invention, it is possible to provide an electrochromic display element that can be driven at a low voltage with little deterioration in display quality even after repeated use over a long period of time and has excellent memory characteristics.

  Hereinafter, embodiments for carrying out the present invention will be described in detail.

  As a result of intensive investigations in view of the above problems, the present inventor has found that, in a display element containing an electrochromic medium between at least a pair of opposed electrodes, the electrochromic medium is an oxidative coloring type electrochromic compound, The display element comprising the compound represented by the formula (1), an electrolyte, and an oxidation reaction type compound or a reduction reaction type compound can reduce display quality even in repeated use over a long period of time. It has been found that an electrochromic display element that can be driven at a low voltage with a small amount and has excellent memory characteristics can be realized, and the present invention has been achieved.

  Hereinafter, details of each component of the display element of the present invention will be described.

[Oxidative coloring type electrochromic compound]
One feature of the display element of the present invention is that the electrochromic medium contains an oxidative coloring electrochromic compound.

  The oxidative coloring type electrochromic compound applicable to the present invention can be selected from various dyes used as pH indicators, azo dyes, phenothiazine derivatives, and the like. For example, a triallylmethane compound, a bisphenylmethane compound, a xanthene compound, a fluorane compound, a thiazine compound, a spiropyran compound, and the like can be given.

  Among the oxidative coloring electrochromic compounds according to the present invention, a compound having a structure represented by the following general formula (A) is preferable in that it can synthesize compounds of various colors and has a relatively rapid color development rate. .

In the general formula (A), X is a carbon atom or a nitrogen atom, and R ₄ and R ₅ each represent a substituted or unsubstituted aromatic group, a group having a substituted or unsubstituted heterocyclic ring, or a fluorane group. . R ₄ and R ₅ may form part of the fluorane skeleton. R ₆ represents a hydrogen atom, a halogen atom, a substituted or unsubstituted acyl group, an alkyl group, an alkoxy group, a nitro group, an aryl group, or an amino group, and R ₆ is any position on the ring, preferably the 5-position or It binds to the 6th position.

The electrochromic compound having the structure represented by the general formula (A) in the chemical structure causes bond cleavage between oxygen and carbon on the side that is not double-bonded to oxygen by an oxidation reaction. Color develops. As shown below, this reaction is reversible and can be returned to colorless by a reduction reaction. In the formula, A ⁻ is an anion.

  An example of an electrochromic compound having such a structure represented by the general formula (A) in the chemical structure is shown below, but the present invention is not limited only to these exemplified compounds. For example, some thermosensitive dyes shown in Fig. 7 of "Application of functional dyes" (directed by Masahiro Irie, published by CMC Publishing Co., Ltd.) exhibit electrochromic properties. Can be changed.

  The preferred amount of the electrochromic compound having the structure represented by the general formula (A) according to the present invention in its chemical structure is determined depending on the color developability and the required color density. The color developability can be calculated from the absorbance coefficient at the time of color development, and a small amount of an electrochromic compound having a high absorbance coefficient may be added.

[Compound represented by the general formula (1)]
In the display element of the present invention, one of the characteristics is that the electrochromic medium contains the compound represented by the general formula (1).

In the general formula (1), M ₁ is an element belonging to Group 15 of the periodic table and does not contain nitrogen. R ₁ , R ₂ and R ₃ each represent an aryl group having a substituent or an aryl group having no substituent, and may be the same or different from each other.

  The compound represented by the general formula (1) according to the present invention is an electrochromic display element obtained by repeating the coloring and decoloring operations of an electrochromic compound having the structure represented by the general formula (A) in the chemical structure. Has a function of suppressing deterioration of display quality.

  The compound represented by the general formula (1) is preferably added in the range of 1 to 50% by mass with respect to the content of the electrochromic compound, from the viewpoint of sufficiently exhibiting the above display quality deterioration suppressing function. Is more preferably added in an amount of 10 to 50% by mass.

  Specific examples of the compound represented by the general formula (1) are listed below, but the present invention is not limited to these exemplified compounds.

[Compounds represented by general formula (2) and general formula (3)]
In the display element of the present invention, it is preferable that the electrochromic medium further contains a compound represented by the general formula (2) or the general formula (3).

In the general formula (2), R ₇ , R ₈ , R ₉ and R ₁₀ each represent a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group or an alkoxycarbonyl group. R ₇ , R ₈ , R ₉ and R ₁₀ are not all hydrogen atoms at the same time. Adjacent R ₇ and R ₈ may be condensed with each other to form a 5-membered or 6-membered condensed ring. Adjacent R ₉ and R ₁₀ may be condensed with each other to form a 5-membered or 6-membered condensed ring. In the general formula (3), R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ each represent a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group or an alkoxycarbonyl group. R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ are not all hydrogen atoms at the same time. One or both of adjacent R ₁₁ and R ₁₂ , or adjacent R ₁₃ and R ₁₄ form a condensed ring. When one of adjacent R ₁₁ and R ₁₂ , or adjacent R ₁₃ and R ₁₄ forms a condensed ring, the other two groups are both hydrogen atoms. The condensed ring is a 5-membered ring or a 6-membered ring.

  The compounds of the compounds represented by the general formula (2) and the general formula (3) have a function of further suppressing deterioration of display quality due to repeated coloring and decoloring operations of the oxidative coloring electrochromic compound. The addition amount of these compounds is preferably 1 to 20% by mass with respect to the content of the oxidative coloring electrochromic compound. For sufficient expression of the function, the addition amount is preferably 5 to 20% by mass.

  In order to explain these compounds more specifically, examples of the compound represented by the general formula (2) include the following exemplary compounds 2-1 to 2-11 and examples of the compound represented by the general formula (3). As shown in the following exemplary compounds 3-1, 3-2. Since these are examples, the compounds represented by the general formula (2) and the general formula (3) are not limited.

〔Electrolytes〕
In the display element of the present invention, one of the characteristics is that the electrochromic medium contains an electrolyte.

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

(Supporting electrolyte)
As the supporting electrolyte that can be used in the display element of the present invention, salts, acids, and alkalis that are usually used in the field of electrochemistry or the field of batteries can be used.

  There are no particular limitations on the salts, and for example, inorganic ion salts such as alkali metal salts and alkaline earth metal salts; quaternary ammonium salts; cyclic quaternary ammonium salts; quaternary phosphonium salts and the like can be used.

Specific examples of the salts include halogen ions, SCN ⁻ , ClO ₄ ⁻ , BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , PF _{^{6 -, AsF 6 -, CH}} 3 COO -, CH 3 (C 6 H 4) SO 3 -, and _{(C 2 F 5 SO 2)} 3 C - Li salt having a counter anion selected from, Na salt or K salt is mentioned.

Further, halogen ions, SCN ⁻ , ClO ₄ ⁻ , BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , PF ₆ ⁻ , AsF _{6 ^{-, CH 3 COO -, CH}} 3 (C 6 H 4) SO 3 -, and _{(C 2 F 5 SO 2)} 3 C - 4 quaternary ammonium salt having a counter anion selected from, specifically, (CH ₃ ) ₄ NBF ₄ , (C ₂ H ₅ ) ₄ NBF ₄ , (n-C ₄ H ₉ ) ₄ NBF ₄ , (C ₂ H ₅ ) ₄ NBr, (C ₂ H ₅ ) ₄ NClO ₄ , (n- C ₄ H ₉ ) ₄ NClO ₄ , CH ₃ (C ₂ H ₅ ) ₃ NBF ₄ , (CH ₃ ) ₂ (C ₂ H ₅ ) ₂ NBF ₄ , (CH ₃ ) ₄ NSO ₃ CF ₃ , (C ₂ H _{5) 4 NSO 3 CF 3,} (n-C 4 H 9 ₄ NSO ₃ CF _3,
Furthermore,

Etc.

Further, halogen ions, SCN ⁻ , ClO ₄ ⁻ , BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , PF ₆ ⁻ , AsF _{6 ^{-, CH 3 COO -, CH}} 3 (C 6 H 4) SO 3 -, and _{(C 2 F 5 SO 2)} 3 C - phosphonium salt having a counter anion selected from, specifically, _(CH 3) ₄ PBF ₄ , (C ₂ H ₅ ) ₄ PBF ₄ , (C ₃ H ₇ ) ₄ PBF ₄ , (C ₄ H ₉ ) ₄ PBF _{4 and the} like. Moreover, these mixtures can also be used suitably.

The supporting electrolyte of the present invention is preferably a quaternary ammonium salt, particularly preferably a quaternary spiro ammonium salt. The _ClO ⁴ as counter anion ^{_{-, BF 4 -, CF 3}} SO 3 -, (C 2 F 5 SO 2) 2 N -, PF 6 - are preferable, and BF ₄ ^- is preferable.

  The amount of the electrolyte salt used is arbitrary, but in general, the electrolyte salt is present in the solvent as an upper limit of 20 mol / L or less, preferably 10 mol / L or less, more preferably 5 mol / L or less. The lower limit is usually 0.01 mol / L or more, preferably 0.05 mol / L or more, more preferably 0.1 mol / L or more.

  In the case of a solid electrolyte, the following compounds exhibiting electronic conductivity and ionic 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. Fluorine-containing compounds such as chalcogenides, 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 Examples thereof include ₇ Cl ₁₃ , Rb ₃ Cu ₇ Cl ₁₀ , LiN, Li ₅ NI ₂ , and Li ₆ NBr ₃ .

(Ionic liquid)
The ionic liquid referred to in the present invention is also called a room temperature molten salt, and is a salt having a melting point of 100 ° C. or lower. This salt is composed of the same number of cations and anions, and there are many substances having a melting point below room temperature depending on the molecular structure, and these are in a liquid state at room temperature without adding any solvent. An ionic liquid has a strong characteristic that it has a strong electrostatic interaction and thus has almost no vapor pressure, and does not evaporate even at high temperatures.

  The ionic liquid used in the present invention may be any substance that is generally studied and reported. In particular, an organic ionic liquid has a molecular structure that exhibits a liquid in a wide temperature range including room temperature.

The ionic liquid that can be suitably used in the present invention is represented by the formula Q ⁺ A ⁻ and is 20 to 100 ° C., preferably 20 to 80 ° C., more preferably 20 to 60 ° C., and still more preferably 20 to 40 ° C. In particular, it refers to a salt that exists as a liquid at 20 ° C., and the viscosity (25 ° C.) is not particularly limited as long as it is a melt at normal temperature, but it is preferably 1 to 200 mPa · s. Further, the cation component represented by Q + in the formula is preferably an onium cation, and more preferably an ammonium cation, an imidazolium cation, a pyridinium cation, a sulfonium cation, and a phosphonium cation.

The above-described ionic fluid will be specifically described in detail. As Q ⁺ in the above formula, R ₁ R ₂ R ₃ R ₄ N ⁺ , R ₁ R ₂ R ₃ S ⁺ , R ₁ R ₂ R ₃ R ₄ P ⁺ , R ₁ R ₂ N ⁺ = CR ₃ R ₄ , R ₁ R ₂ P ⁺ = CR ₃ R ₄ [where R ₁ to R ₄ are, independently of one another, hydrogen, saturated or unsaturated carbon C 1 -C 12 alkyl group, a cycloalkyl group having 3 to 8 carbon atoms, an aryl group or an aralkyl group having a carbon number of 7-11 having 6 to 10 carbon _{atoms, R 5 -X- (R 6 -Y-} ) n - (Wherein R ₅ represents an alkyl group having 4 or less carbon atoms, R ₆ represents an alkylene group having 4 or less carbon atoms, X and Y represent an oxygen atom or a sulfur atom, and n represents an integer of 0 to 10). And the group may be substituted] ammonium selected from the group consisting of Phosphonium _{^{ion, R 1 R 2 N + =}} CR 3 -R 7 -R 3 C = N + R 1 R 2, R 1 R 2 S + -R 7 -S + R 1 R 2, R 1 R 2 P + ^{_{= CR 3 -R 7 -R 3 C}} = P + R 1 R 2 ( _wherein, R 1, _{R 2} and _{R 3} are the same as defined above, and _{R 7} is 1 to carbon atoms A quaternary ammonium and / or phosphonium ion selected from the group consisting of 6 alkylene or phenylene groups, which may have a substituent, and nitrogen represented by the following general formula: Examples thereof include nitrogen ions containing 1, 2 or 3 atoms selected from sulfur and phosphorus atoms, ammonium ions derived from sulfur and phosphorus atom-containing heterocycles, sulfonium ions, phosphonium ions, and the like.

Wherein R ₁ and R ₂ are as defined above, and Z is an atom capable of constituting a 4-10 membered ring containing N ⁺ , N ⁺ = C, S ⁺ , P ⁺ or P ⁺ = C And the constituent atoms may have a substituent.

Specific examples of R ₁ to R _{4 in} the above are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, A linear or branched alkyl group such as nonyl and decyl; a cycloalkyl group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl; unsubstituted or halogen atoms (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 alkyl Amino group include phenyl having one to three substituents, such as di-lower alkyl amino group, naphthyl, tolyl, aryl group xylyl, and the like aralkyl groups such as benzyl. Further, specific examples of _{R 5} include methyl, ethyl, n- propyl, isopropyl, n- butyl, isobutyl, sec- butyl, and alkyl group such as tert- butyl group, methylene as _{R 6} And alkylene groups such as ethylene, propylene and butylene groups. Furthermore, specific examples of R ₇ include alkylene groups such as methylene, ethylene, propylene, and butylene, and phenylene groups such as phenylene.

Further, A in the formula ^- Examples of the counter anion represented by, hexafluorophosphate, hexafluoroantimonate, hexafluoroarsenate, fluorosulfonate salts, tetrafluoroborate, nitrate, alkyl sulfonate Represents a fluorinated alkyl sulfonate or a hydrogen sulfate.

  Furthermore, WO95 / 18456, JP-A-8-259543, JP-A-2001-243959, Electrochemical Vol.65, No.11, p.923 (1997), EP-716288, J. Org. Electrochem. Soc. , Vol. 143, no. 10, 3099 (1996), Inorg. Chem. The pyridinium salts, imidazolium salts, triazolium salts and the like described in 1996, 35, 1168 to 1178 can be selected and used in a timely manner according to the present invention.

(Solid electrolyte, gel electrolyte)
The electrolyte according to the present invention is not only a solution electrolyte composed of a solvent or an ionic liquid, but also a high-viscosity electrolyte or gel electrolyte (hereinafter, referred to as a solid electrolyte or a polymer compound containing substantially no solvent). Gel electrolyte) can be used.

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

[Oxidation reaction type compound and reduction reaction type compound]
In the display element of the present invention, one of the characteristics is that the electrochromic medium contains an oxidation reaction type compound or a reduction reaction type compound.

  The oxidation reaction type compound and the reduction reaction type compound according to the present invention have an effect of assisting and stabilizing the reaction when the electrochromic compound is oxidized to develop color.

(Oxidation reaction type compound)
The oxidation reaction type compound according to the present invention has an effect of assisting and stabilizing the color reaction of the electrochromic compound. By adding the oxidation reaction type compound according to the present invention to the electrochromic medium, the oxidation reaction of the electrochromic compound is carried out via this oxidation reaction type compound, so that driving stability is improved. Preferred as the oxidation-reactive compound according to the present invention is a compound having an oxidation potential lower than that of the electrochromic compound and substantially not colored before and after the reaction or slightly colored in the same color tone as the electrochromic compound. .

  The oxidation potential as used in the present invention can be measured by a cyclic voltammogram.

Specifically, the cyclic voltammogram can be measured by, for example, the cyclic voltammetry method of an electrochemical analyzer ALS600C manufactured by BAS. For the measurement, a solution prepared by dissolving the oxidizing active compound according to the present invention and a supporting electrolyte such as tetrabutylammonium perchloride in an appropriate solvent, for example, acetonitrile, is prepared, and the RE-5 non-aqueous solvent reference electrode manufactured by BAS is referred to. A cyclic voltammogram can be measured under the conditions of an electrode (Ag / Ag ⁺ ), a Pt working electrode, a Pt counter electrode, and a scanning speed of 100 mV / sec.

  When a clear peak cannot be confirmed in the electrochromic compound, a potential at which coloring of the electrochromic compound starts to be confirmed can be read and used as an oxidation potential.

  As such an oxidation reaction type compound, metallocene derivatives such as ferrocene, phenothiazine derivatives, or the compounds shown below are known. The display element of the present invention, that is, the electrochromic compound and the general formula (1) In the system in which the compound is present, N-oxyl derivative, N-hydroxyphthalimide derivative, compound having NO bond of hydroxamic acid derivative, allyloxy free radical introduced with bulky substituent at O-position of galvinoxyl The compound which has is effective. These compounds are very preferable because they all have a low oxidation potential and are hardly colored before and after the reaction.

  As N-oxyl derivatives, derivatives substituted with various substituents such as TEMPO (2,2,6,6-tetramethylpiperidinyl-N-oxyl) are commercially available. In addition, various derivatives including polymers can be easily synthesized according to known literature.

  In general, it is known that when hydrogen is substituted on the α-position carbon of the nitroxide radical, it is easily disproportionated to hydroxyamine and nitrone. For this reason, the four methyl groups at the N-oxyl group α-position of TEMPO can be said to be indispensable structures for existing as stable radicals, but conversely, the reactivity may decrease due to steric hindrance of these four methyl groups. is there. An azaadamantane N-oxyl derivative or an azabicyclo N-oxyl derivative is preferred in that it does not cause a decrease in activity.

  N-hydroxyphthalimide (NHPI) and the like are known as N-hydroxyphthalimide derivatives.

  Examples of the hydroxamic acid derivative include trihydroxyimino cyanuric acid (THICA).

<N-oxyl derivative>
The N-oxyl derivative can be represented by the following general formula (M1), and compounds represented by the following general formulas (M2) to (M5) are more preferable. In particular, a polycyclic N-oxyl derivative represented by the general formula (M6) is preferable. The oxidation reaction type compound represented by the general formula (M6) Am. Chem. Soc. , 128, 8412 (2006) and Tetrahedron Letters 49 (2008) 48-52. Moreover, the oxidation reaction type compound which polymerized these is Unexamined-Japanese-Patent No. 2004-227946, 2004-228008, 2006-73240, 2007-35375, 2007-70384, for example. , 2007-184227, 2007-298713 and the like.

  Details of the oxidation reaction type compounds represented by the general formulas (M1) to (M6) will be described below.

  First, the compound represented by general formula (M1) is demonstrated.

In the general formula (M1), Rm ₁₁ and Rm ₁₂ are each independently an aliphatic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic group or>C═O,> C═S, which may have a substituent. ,> C = N—Rm represents a group bonded to a nitrogen atom via ₁₃ . Rm ₁₃ represents a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aromatic hydrocarbon group or a heterocyclic group. Rm ₁₁ and Rm ₁₂ may be connected to each other to form a cyclic structure.

  The aliphatic hydrocarbon group includes chain and cyclic groups, and the chain group includes linear and branched groups. Such aliphatic hydrocarbon groups include methyl, ethyl, vinyl, propyl, isopropyl, propenyl, butyl, iso-butyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, iso-hexyl, cyclohexyl, cyclohexenyl, Examples include octyl, iso-octyl, cyclooctyl, 2,3-dimethyl-2-butyl and the like.

  Examples of the aromatic hydrocarbon group include a phenyl group and a naphthyl group. Examples of the heterocyclic group include a pyridyl group, a thiazolyl group, an oxazolyl group, an imidazolyl group, a furyl group, a pyrrolyl group, a pyrazinyl group, a pyrimidinyl group, and a pyridazinyl group. , Serenazolyl group, sulfolanyl group, piperidinyl group, pyrazolyl group, tetrazolyl group, morpholino group and the like.

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

  The compound represented by the general formula (M1) may be a multimer such as a dimer or trimer linked by these substituents, or may be a polymer.

  As a more preferable structure as the N-oxyl derivative, compounds represented by the general formulas (M2) to (M6) will be described below. That is, the compounds of the general formulas (M2) to (M6) are included in the general formula (M1).

  Next, the compound represented by formula (M2) will be described.

In the general formula (M2), Rm ₂₁ , Rm ₂₂ , Rm ₂₃ , and Rm ₂₄ are each independently an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a heterocyclic ring that may have a hydrogen atom or a substituent. Represents a group. These aliphatic hydrocarbon group, aromatic hydrocarbon group, and heterocyclic group have the same meanings as those in formula (M1).

Z ₁ represents an atomic group necessary for forming a cyclic structure, and preferably forms a 5-membered ring or a 6-membered ring. Z ₁ may further have a substituent, and examples of the substituent include the same substituents as exemplified in the general formula (M1). The atoms constituting Rm _{21 to} Rm ₂₄ and Z ₁ may be linked to each other to form a cyclic structure. For example, together with the nitrogen atom, a polycyclic structure such as an azanorbornene structure or an azaadamantane structure is taken. Also good.

  The ring structure of the compound represented by the general formula (M2) is preferably a piperidine ring, a pyrrolidine ring, or an azaadamantane ring.

  Next, the compound represented by formula (M3) will be described.

  In this invention, it is one of the preferable aspects that the N-oxyl derivative based on this invention is a compound represented by general formula (M3).

In the general formula (M3), Rm ₃₁ is an aliphatic hydrocarbon group or aromatic hydrocarbon which may be substituted directly or substituted with a carbonyl carbon atom via an oxygen atom, a nitrogen atom or a sulfur atom. Rm ₃₂ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a heterocyclic group which may have a substituent. These aliphatic hydrocarbon group, aromatic hydrocarbon group, and heterocyclic group have the same meanings as those in formula (M1). Rm ₃₁ and Rm ₃₂ may be connected to each other to form a cyclic structure.

In the general formula (M3), Rm ₃₂ is preferably an aromatic hydrocarbon group, particularly preferably a phenyl group which may have a substituent. The substituent on the phenyl group is preferably an electron-withdrawing group such as a cyano group, an alkoxycarbonyl group, or a trifluoromethyl group. Rm ₃₁ is preferably a phenyl group or an aliphatic hydrocarbon group directly bonded to a carbonyl carbon atom, particularly preferably a branched alkyl group or a cycloalkyl group. Note that it is preferable that the compound represented by the general formula (M3) be added in a state of N—OH to manufacture a display element.

  Next, the compound represented by formula (M4) will be described.

  In this invention, it is one of the preferable aspects that the N-oxyl derivative which concerns on this invention is a compound represented by the said general formula (M4).

In the above general formula (M4), Z ₂ represents an atomic group necessary for forming a cyclic structure, and preferably forms a 5-membered ring or a 6-membered ring. Z ₂ may further have a substituent, and examples of the substituent include the substituents exemplified in Formula (M1). Z ₂ may be a condensed ring. Note that the compound represented by the general formula (M4) is preferably added in the state of N—OH to manufacture a display element.

  Next, the compound represented by formula (M5) will be described.

  In this invention, it is one of the preferable aspects that the N-oxyl derivative which concerns on this invention is a compound represented by the said general formula (M5).

In the general formula (M5), Rm _{51 to} Rm ₅₅ each independently represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a heterocyclic group which may have a substituent. These aliphatic hydrocarbon group, aromatic hydrocarbon group, and heterocyclic group have the same meanings as those in formula (M1).

In the general formula (M5), Rm ₅₁ is preferably an aromatic hydrocarbon group, particularly preferably a phenyl group which may have a substituent. The substituent on the phenyl group is preferably an electron-withdrawing group such as a cyano group, an alkoxycarbonyl group, or a trifluoromethyl group. The Rm ₅₂ ~Rm _55, preferably an alkyl group having 1 to 6 carbon atoms, a methyl group is particularly preferred.

  Next, the compound represented by formula (M6) will be described.

In the general formula (M6), Rm ₆₁ and Rm ₆₂ each independently represent a hydrogen atom or an aliphatic hydrocarbon group which may have a substituent. Rm ₆₁ and Rm ₆₂ are preferably a hydrogen atom or a linear alkyl group having 4 or less carbon atoms, and at least one of Rm ₆₁ and Rm ₆₂ is preferably a hydrogen atom.

Z ₃ , Z ₄ and Z ₅ each represent an atomic group necessary for forming a cyclic structure (for example, carbon, nitrogen, oxygen, sulfur, etc.) and each form a 5-membered ring or a 6-membered ring. preferable. Z ₃ , Z ₄ and Z ₅ may further have a substituent.

  n represents 0 or 1, but when n = 0, the general formula (M6) represents a bicyclo compound, and when n = 1, a tricyclo compound.

  As the compound represented by the general formula (M6), n = 1 is preferable, and an azaadamantane derivative is particularly preferable.

  Specific examples of the compounds represented by the general formulas (M1) to (M6) that can be used in the present invention are shown below, but are not limited thereto.

  Examples of the compound having an allyloxy free group having a bulky substituent introduced at the O-position, such as galvinoxyl, which is a preferable oxidation reaction type compound used in the present invention, include the following compounds, but are not limited thereto. It is not something.

(Reduction reaction type compound)
In the display element of the present invention, the effect of improving the memory property can be exhibited particularly by containing the reduction reaction type compound in the electrochromic medium. When the electrochromic compound causes a color development reaction at the observation side electrode, surplus charges are generated at the non-observation side electrode. In the display element of the present invention, since the coloring and decoloring reaction of the electrochromic compound used is reversible, the decoloring reaction of the electrochromic compound occurs due to this excess charge when the application of voltage is stopped. . In response to the above problem, by adding a reduction reaction type compound to the electrochromic medium, even if this excess charge reacts with the reduction reaction type compound and the voltage application is stopped, the electrochromic decolorization reaction can be easily performed. It won't happen.

  The reduction reaction-type compound suitable for the present invention is preferably a compound that does not substantially color when it undergoes a reduction reaction or slightly develops the same color as electrochromic. However, as described later, when a white scatterer is mixed in an electrochromic medium when used as a reflective display element, the reaction at the non-observation side electrode is concealed by the white scatterer. It is possible to use even those that change.

  Examples of compounds that are effective as the reduction reaction type compounds according to the present invention include thianthrene derivatives, tetrathiafulvalene derivatives, tetracyanoquinodimethane derivatives, hydrazyl free radical compounds such as verdazil, thiazyl free radical compounds, hydrazone derivatives, and the like. .

  Below, an example of the reduction reaction type compound applicable to this invention is shown. The present invention is not limited to these exemplified compounds.

  Furthermore, more preferred reduction reaction type compounds in the present invention include ethanedione derivatives, tetrazolium salts, formazan derivatives, phenazine derivatives, phenoxazine derivatives, acridine derivatives, and diphenylethanedione derivatives. All of these compounds exhibit good reversible reactivity.

  An ethanedione derivative that can be suitably used in the present invention has a structure represented by the following general formula (M7).

In the general formula (M7), Rm ₇₁ and Rm ₇₂ each independently represent an aromatic hydrocarbon group, an aromatic heterocyclic group or an aliphatic group which may have a substituent. Rm ₇₁ and Rm ₇₂ may be connected to each other to form a cyclic structure.

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

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

  The compound represented by the general formula (M7) may be a multimer such as a dimer or trimer linked by these substituents, or may be a polymer.

In the general formula (M7), Rm ₇₁ and Rm ₇₂ are preferably an aromatic hydrocarbon group or an aromatic heterocyclic group, particularly an aromatic hydrocarbon group substituted with an electron-withdrawing group or an electron-deficient aromatic heterocyclic group. Is preferred. The electron-withdrawing group is an electron-withdrawing group having a Hammett's substituent constant σp value of 0 or more. Preferably, it is an electron withdrawing group having a σp value of 0.2 or more. The upper limit is preferably an electron withdrawing group of 1.0 or less. More preferably, it is an electron withdrawing group of 0.75 or less. Hammett's rule was found in 1935 by L. L. in order to quantitatively discuss the effect of substituents on the reaction or equilibrium of benzene derivatives. P. A rule of thumb proposed by Hammett, which is widely accepted today. Substituent constants determined by Hammett's rule include a σp value and a σm value, and these values are described in many general books. A. Dean, “Lange's Handbook of Chemistry”, 12th edition, 1979 (McGraw-Hill) and “Chemical Areas Extra”, 122, 96-103, 1979 (Nan-Edo). However, it does not mean that the values known in the literature described in these texts are limited to only certain substituents, as long as the values are unknown based on Hammett's rule and are included within the range. Of course included.

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

  Specific examples of the compound represented by the general formula (M7) are shown below, but the present invention is not limited to these compounds.

  A tetrazolium salt represented by the following general formula (M8) can also be suitably used as the reduction reaction type compound of the present invention.

In the general formula (M8), Rm ₈₁ and Rm ₈₂ are substituted or unsubstituted aromatic groups which may be the same or different, and Rm ₈₃ is an alkyl group, a carboxyl group, an amino group, a substituted or unsubstituted group. An aromatic group or a substituted or unsubstituted heterocyclic group is represented.

  As the counter ion forming the salt, chlorine, bromine, perchloric acid, tetrafluoroboric acid, and the like are preferably used, but are not limited thereto.

  Examples of the compound represented by the general formula (M8) include 2,3,5-triphenyltetrazolium salt, 2,3,5-tris (p-tolyl) tetrazolium salt, 2,3-bis (3- Chlorophenyl) -5-phenyltetrazolium salt, 2,3-bis (3-fluorophenyl l) -5-phenyltetrazolium salt, 2,3-bis (3-methylphenyl l) -5-phenyltetrazolium salt, 2,3 -Bis (4-chlorophenyl l) -5-phenyltetrazolium salt, 2,3-bis (4-ethylphenyl l) -5-phenyltetrazolium salt, 2,3-bis (4-fluorophenyl l) -5-phenyl Tetrazolium salt, 2,3-bis (4-methoxyphenyl) -5- (4-cyanophenyl) tetrazolium salt, 2,3-bis (4-methoxy) Phenyl) -5-phenyltetrazolium salt, 2,3-bis (4-methylphenyl) -5- (4-cyanophenyl) tetrazolium salt, 2,3-bis (4-nitrophenyl) -5-phenyltetrazolium salt Hyde 2,3-di (p-tolyl) -5-phenyltetrazolium salt, 2,3-diphenyl-5- (2-thienyl) tetrazolium salt, 2,3-diphenyl-5- (4-chlorophenyl) tetrazolium salt 2,3-diphenyl-5- (4-methoxyphenyl) tetrazolium salt, 2,3-diphenyl-5- (p-tolyl) tetrazolium salt, 2,3-diphenyl-5-aminotetrazolium salt, 2,3- Diphenyl-5-carboxytetrazolium salt, 2,3-diphenyl-5-ethyltetrazolium salt, 2,3-diphe Ru-5-methyltetrazolium salt, 2,5-di (p-tolyl) -3-phenyltetrazolium salt, 2,5-diphenyl-3- (4-styrylphenyl) tetrazolium salt, 2- (2-benzothiazole) -3,5-diphenyltetrazolium bromide, 2- (2-benzothiazole) -3- (4-nitrophenyl l) -5-phenyltetrazolium bromide, 2- (4-iodophenyl) -3- (4-nitrophenyl) ) -5-phenyltetrazolium salt, 2-phenyl-3- (4-biphenylyl) -5-methyltetrazolium salt, 3,3 '-(3,3'-dimethoxy-4,4'-diphenylene) bis (2- Phenyl-5-veratryltetrazolium salt), 3- (3-nitrophenyl) -5-methyl-2-phenyltetrazolium salt, 3 (4,5-dimethyl-2-thiazolyl) -2,5-diphenyltetrazolium bromide, 3- (4-nitrophenyl) -5-methyl-2-phenyltetrazolium salt, blue tetrazolium (ditetrazolium salt), m-tolyl Tetrazolium red (2,5-diphenyl-3- (m-tolyl) tetrazolium salt), nitro blue tetrazolium (2,2'-di-p-nitrophenyl-5,5'-diphenyl- (3,3'-dimethoxy) ) -4,4'-bisphenyleneditetrazolium salt), o-tolyltetrazolium red (2,5-diphenyl-3- (o-tolyl) tetrazolium salt), p-tolyltetrazolium red (2,5-diphenyl-3) -(P-tolyl) tetrazolium salt), tetranitro blue tetrazolium ( , 3 '-(3,3'-dimethoxy-4,4'-diphenylene) bis-2,5-di (p-nitrophenyl) -2H-tetrazolium salt), tetrazolium violet (3- (1-naphthyl)- 2,5-diphenyl-2H-tetrazolium salt), 3- (4-iodophenyl) -2- (4-nitrophenyl) -5-phenyl-1,2,3,4-tetrazole, thiocarbamylnitro blue tetrazolium A salt etc. can be mentioned.

  Furthermore, the compound example represented by general formula (M8) is shown below.

  The formazan derivative is a compound represented by the following general formula (M9).

In the general formula (M9), Rm ₉₁ represents a hydrogen atom or a substituent, and preferably a hydrogen atom. Rm ₉₂ , Rm ₉₃ and Rm ₉₄ each represent a substituted or unsubstituted aromatic group or heterocyclic group which may be the same or different.

  Examples of the formazan derivative represented by the following general formula (M9) include 1,3,5-triphenylformazan, 1,5-bis (4-methoxyphenyl) -3-phenylformazan, and 1,5-diphenyl- 3- (2-thienyl) formazan, 1,5-diphenyl-3- (4-chlorophenyl) formazan, 1,5-diphenyl-3- (4-methoxyphenyl) formazan, 1,5-diphenyl-3- (p -Tolyl) formazan, 1- (4-nitrophenyl) -3-methyl-5-phenylformazan, 3,5-diphenyl-1- (1-naphthyl) formazan, 3,5-diphenyl-1- (4-bi) Phenylyl) formazan, 3,5-diphenyl-1- (m-tolyl) formazan, 3,5-diphenyl-1- (o-tolyl) formazan, 3,5-diph Nyl-1- (p-tolyl) formazan, 5- (2-benzothiazole) -1,3-diphenylformazan, INT formazan (1- (4-iodophenyl) -5- (4-nitrophenyl) -3- Phenylformazan), MTT formazan (1- (4,5-dimethyl-2-thiazolyl) -3,5-diphenylformazan), neo-tetrazolium, nitro blue tetrazolium diformazan (5,5'-bis (4-nitrophenyl) -3,3'-diphenyl-1,1 '-[(3,3'-dimethoxy) -4,4'-bisphenylene) diformazan), tetrazole blue diformazan, TNBT diformazan (1,1'-(3,3 '-Dimethoxy-4,4'-diphenylene) bis-3,5-di (p-nitrophenyl) diformazan) And the like zinc-reagent (2-carboxy-2'-hydroxy-5'-sulfo Hol Magill benzene sodium salt).

  The phenazine applicable to the present invention is a compound represented by the following formula (M10).

  As this derivative, it is possible to introduce a hydroxyl group, an alkyl group, an alkoxy group or the like into any carbon. For example, phenazine, 1-hydroxyphenazine, 1-methoxyphenazine, 5,10-dihydro-5,10- Dimethylphenazine and the like are known.

  The phenoxazine applicable to the present invention is a compound represented by the following formula (M11). As this derivative, for example, 4,6-bis (diphenylphosphino) phenoxazine is known.

  The acridine applicable to the present invention is a compound represented by the following formula (M12). Examples of the derivatives include 9-methylacridine, 9-phenylacridine, 9- (bromomethyl) acridine, 1,2,3,4,5,6,7,8-octahydroacridine, and 9-acridinecarboxylic acid water. Japanese-style products, 9-aminoacridine hydrochloride monohydrate and the like.

  In the display element of the present invention, the oxidation reaction type compound and the reduction reaction type compound according to the present invention described above are contained in an electrochromic medium. As the form in which the oxidation reaction type compound and the reduction reaction type compound are contained in the electrochromic medium, the compound may be dissolved in the electrochromic medium and freely movable, or contacted with the electrochromic medium. It may be immobilized on the electrode surface. More preferably, it has a nanoporous layer on the electrode surface on the observation side, and the oxidation reaction type compound according to the present invention is immobilized on the nanoporous layer, and also on the electrode surface on the non-observation side. When the nanoporous layer is provided, the reduction reaction type compound is preferably immobilized on the nanoporous layer.

  By forming a nanoporous layer on the electrode surface in contact with the electrochromic medium, it becomes possible to increase the amount of oxidation-reactive compound or reduction-reactive compound that can be immobilized. Since it is possible to contact the electrode through the hole, the electrochromic reactivity is not deteriorated. Even if the oxidation reaction type compound or the reduction reaction type compound is immobilized on the surface of the electrode or the nanoporous layer formed on the electrode surface, it remains in contact with the electrochromic medium and retains the reactivity. , Defined as substantially contained in an electrochromic medium.

  The method of immobilizing on the electrode surface includes a method of introducing a group that chemically or physically adsorbs with the electrode surface into the oxidation reaction type compound and the reduction reaction type compound according to the present invention, or the oxidation reaction type compound or reduction according to the present invention. Examples thereof include a method in which a reactive compound is polymerized to form a thin film on the electrode surface.

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

The immobilization according to the present invention is preferably performed by chemical adsorption, and the adsorptive groups to be chemically adsorbed include —COOH, —P═O (OH) ₂ , —OP═O (OH) ₂ and —Si (OR) ₃ ( R represents an alkyl group).

〔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. Excellent in preventing dirt. As an electrode manufacturing method, an existing method such as an evaporation method, a printing method, an ink jet method, a spin coating method, or a CVD method can be used.

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

〔solvent〕
In the electrolyte according to the present invention, a solvent that is generally used in electrochemical cells and batteries and that can dissolve various additives such as metal salt compounds and promoters that are reversibly dissolved and precipitated by an electrochemical oxidation-reduction reaction. Can be used.

  Specifically, acetic anhydride, methanol, ethanol, tetrahydrofuran, ethylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, butylene carbonate, propylene carbonate, nitromethane, acetonitrile, acetylacetone, N-methylformamide, N, N-dimethylformamide , Dimethyl sulfoxide, hexamethylphosphoamide, dimethoxyethane, diethoxyfuran, γ-butyrolactone, γ-valerolactone, sulfolane, propionitrile, butyronitrile, glutaronitrile, adiponitrile, methoxyacetonitrile, N-methylacetamide, N, N -Dimethylacetamide, N-methylpropionamide, methylpyrrolidinone, 2- (N-methyl) -2-pyrrolidi Non, dimethyl sulfoxide, dioxolane, trimethyl phosphate, triethyl phosphate, tripropyl phosphate, ethyl dimethyl phosphate, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, tris (Trifluoromethyl) phosphate, tris (pentafluoroethyl) phosphate, triphenyl phosphate, tricresyl phosphate, 2-ethylhexyl phosphate, tetramethylurea, 1,3-dimethyl-2-imidazolidinone, hexamethylphosphotriamide 4-methyl-2-pentanone, dioctyl phthalate, dioctyl sebacate, and ethylene glycol Lumpur, diethylene glycol, polyethylene glycols such as triethylene glycol monobutyl ether and the like can be used.

  Furthermore, room temperature molten salts can also be used as solvents. The room temperature molten salt is a salt composed of ion pairs that are melted at room temperature (that is, in a liquid state) consisting only of ion pairs that do not contain a solvent component, and usually has a melting point of 20 ° C. or lower, A salt consisting of an ion pair that is liquid at a temperature above. The room temperature molten salt can be used alone or in combination of two or more.

  The electrolyte solvent used in the present invention is preferably an aprotic polar solvent, particularly propylene carbonate, ethylene carbonate, dimethyl sulfoxide, dimethoxyethane, acetonitrile, γ-butyrolactone, sulfolane, dioxolane, dimethylformamide, dimethoxyethane, tetrahydrofuran, adiponitrile, Methoxyacetonitrile, dimethylacetamide, methylpyrrolidinone, dimethyl sulfoxide, dioxolane, sulfolane, trimethyl phosphate and triethyl phosphate are preferred. The solvent may be used alone or in combination of two or more.

<Compounds Represented by General Formulas (S1) and (S2)>
In the present invention, particularly preferably used solvents are compounds represented by the following general formula (S1) or (S2).

In the general formula (S1), L represents an oxygen atom or an alkylene group, and Rs ₁₁ to Rs ₁₄ each represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group, or an alkoxy group.

In the general formula (S2), Rs ₂₁ and Rs ₂₂ each represents an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group, or an alkoxy group.

  First, the detail of the compound represented by general formula (S1) is demonstrated.

In the general formula (S1), L represents an oxygen atom or CH ₂ , and Rs ₁₁ to Rs ₁₄ each represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group, or an alkoxy group, These substituents may be further substituted with an arbitrary substituent.

  Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, tert-butyl, pentyl, hexyl, octyl, dodecyl, tridecyl, tetradecyl, pentadecyl, and the like as aryl groups. Examples of the cycloalkyl group such as phenyl group, naphthyl group and the like include, for example, a cyclopentyl group, cyclohexyl group and the like, an alkoxyalkyl group, for example, a β-methoxyethyl group, a γ-methoxypropyl group and the like, as an alkoxy group, Examples thereof include a methoxy group, an ethoxy group, a propyloxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, and a dodecyloxy group.

  Hereinafter, although the specific example of a compound represented by general formula (S1) is shown, in this invention, it is not limited only to these illustrated compounds.

  Subsequently, the detail of the compound represented by general formula (S2) is demonstrated.

In the general formula (S2), Rs ₂₁ and Rs ₂₂ each represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group, or an alkoxy group.

  Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, tert-butyl, pentyl, hexyl, octyl, dodecyl, tridecyl, tetradecyl, pentadecyl, and the like as aryl groups. Examples of the cycloalkyl group such as phenyl group, naphthyl group and the like include, for example, a cyclopentyl group, cyclohexyl group and the like, an alkoxyalkyl group, for example, a β-methoxyethyl group, a γ-methoxypropyl group and the like, as an alkoxy group, Examples thereof include a methoxy group, an ethoxy group, a propyloxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, and a dodecyloxy group.

  Hereinafter, although the specific example of a compound represented by general formula (S2) is shown, in this invention, it is not limited only to these illustrated compounds.

  Of the compounds represented by the general formulas (S1) and (S2) exemplified above, the exemplary compounds (S1-1), (S1-2), and (S2-3) are particularly preferable.

  The compounds represented by the general formulas (S1) and (S2) according to the present invention are one type of electrolyte solvent. However, in the display element of the present invention, another solvent is used as long as the object effects of the present invention are not impaired. Can be used together. Specifically, tetramethylurea, 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, propionitrile, acetonitrile, acetylacetone, 4-methyl-2-pentanone, 2-butanol, 1-butanol, 2 -Propanol, 1-propanol, ethanol, methanol, acetic anhydride, ethyl acetate, ethyl propionate, dimethoxyethane, diethoxyfuran, tetrahydrofuran, ethylene glycol, diethylene glycol, triethylene glycol monobuty Ether, water and the like. Among these solvents, it is preferable to include at least one solvent having a freezing point of −20 ° C. or lower and a boiling point of 120 ° C. or higher.

  Furthermore, as a solvent which 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).

  In the present invention, the electrolyte solvent may be a single type or a mixture of solvents, but a mixed solvent containing ethylene carbonate is preferred. The addition amount of ethylene carbonate is preferably 10% by mass or more and 90% by mass or less of the total electrolyte solvent mass. A particularly preferable electrolyte solvent is a mixed solvent having a mass ratio of propylene carbonate / ethylene carbonate of 7/3 to 3/7. When the propylene carbonate ratio is larger than 7/3, the ionic conductivity is inferior and the response speed is lowered. When the propylene carbonate ratio is smaller than 3/7, the electrolyte tends to be deposited at a low temperature.

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

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

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

In the present invention, among the white particles, titanium dioxide, zinc oxide, and zinc hydroxide are preferably used. In addition, titanium dioxide surface-treated with inorganic oxides (Al ₂ O ₃ , AlO (OH), SiO _2, etc.), in addition to these surface treatments, trimethylolethane, triethanolamine acetate, trimethylcyclosilane, etc. Titanium dioxide subjected to organic treatment can be used.

  Of these white particles, it is more preferable to use titanium oxide or zinc oxide from the viewpoint of coloring prevention at high temperature and the reflectance of the element due to the refractive index.

  In the present invention, examples of the water-based polymer that does not substantially dissolve in the electrolyte solvent include a water-soluble polymer and a polymer dispersed in the water-based solvent.

Examples of water-soluble compounds include proteins such as gelatin and gelatin derivatives, cellulose derivatives, natural compounds such as polysaccharides such as starch, gum arabic, dextran, pullulan and carrageenan, polyvinyl alcohol, polyvinyl pyrrolidone, acrylamide polymers and their Examples include synthetic polymer compounds such as derivatives. As gelatin derivatives, acetylated gelatin, phthalated gelatin, polyvinyl alcohol derivatives as terminal alkyl group-modified polyvinyl alcohol, terminal mercapto group-modified polyvinyl alcohol, and cellulose derivatives include hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose and the like. It is done. Further, Research Disclosure and those described on pages (71) to (75) of JP-A No. 64-13546, US Pat. No. 4,960,681, JP-A No. 62-245260, etc. superabsorbent polymers described, namely -COOM or -SO 3 M _(M is a hydrogen atom or an alkali metal) homopolymer or a vinyl monomer together or with other vinyl monomers of the vinyl monomer having a (e.g., sodium methacrylate, Copolymers with ammonium acid, potassium acrylate, etc.) are also used. These binders can be used in combination of two or more.

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

  Polymers dispersed in an aqueous solvent include latexes such as natural rubber latex, styrene butadiene rubber, butadiene rubber, nitrile rubber, chloroprene rubber, isoprene rubber, polyisocyanate, epoxy, acrylic, silicon, polyurethane, Examples thereof include a thermosetting resin in which urea, phenol, formaldehyde, epoxy-polyamide, melamine, alkyd resin, vinyl resin and the like are dispersed in an aqueous solvent. Of these polymers, it is preferable to use an aqueous polyurethane resin described in JP-A-10-76621.

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

  In the present invention, the water mixture of the water-based 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 admixture of the water-based compound and the white pigment onto the electrode and drying it, and then the silver or silver is chemically treated on the scattering material. After supplying an electrolyte solution containing the compound contained in the structure, it can be sandwiched between opposing electrodes, giving a potential difference between the opposing electrodes, causing a silver dissolution precipitation reaction, and penetrating ions that can move between the electrodes Tell the state.

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

  Examples of the hardener used in the present invention include, for example, U.S. Pat. No. 4,678,739, column 41, 4,791,042, JP-A-59-116655, and 62-245261. No. 61-18942, 61-249054, 61-245153, JP-A-4-218044, and the like. More specifically, aldehyde hardeners (formaldehyde, etc.), aziridine hardeners, epoxy hardeners, vinyl sulfone hardeners (N, N'-ethylene-bis (vinylsulfonylacetamide) Ethane, etc.), N-methylol hardeners (dimethylolurea, etc.), boric acid, metaboric acid or polymer hardeners (compounds described in JP-A-62-234157). When gelatin is used as the aqueous compound, it is preferable to use a vinyl sulfone type hardener or a chlorotriazine type hardener alone or in combination. Moreover, when using polyvinyl alcohol, it is preferable to use boron-containing compounds such as boric acid and metaboric acid.

  These hardeners are used in an amount of 0.001 to 1 g, preferably 0.005 to 0.5 g, per 1 g of the aqueous compound. In addition, it is possible to perform heat treatment and humidity adjustment during the curing reaction in order to increase the film strength.

[Thickener added with electrolyte]
In the display element of the present invention, a thickener can be used for the electrolyte. For example, gelatin, gum arabic, poly (vinyl alcohol), hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose acetate, cellulose acetate butyrate, poly ( Vinylpyrrolidone), poly (alkylene glycol), casein, starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid), copoly (styrene-maleic anhydride), copoly ( Styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinyl acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (esters), poly (urethanes), phenoxy resins, poly (PVC Redene), poly (epoxide) s, poly (carbonates), poly (vinyl acetate), cellulose esters, poly (amides), hydrophobic transparent binders such as polyvinyl butyral, cellulose acetate, cellulose acetate butyrate, polyester, Examples include polycarbonate, polyacrylic acid, polyurethane and the like.

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

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

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

  As a method for forming a porous film, a sintering method (fusion method) (using fine pores formed between particles by adding polymer fine particles or inorganic particles to a binder or the like and partially fusing them), extraction method ( After forming a constituent layer with a solvent-soluble organic or inorganic substance and a binder that does not dissolve in the solvent, the organic or inorganic substance is dissolved with the solvent to obtain pores), and the polymer is heated or degassed Well-known formation methods such as foaming method for foaming, phase change method for phase separation of polymer mixture by manipulating good solvent and poor solvent, and radiation irradiation method for forming pores by radiating various radiations 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 agents, hardeners, surfactants, thickeners, plasticizers, slip agents, UV absorbers, anti-irradiation dyes, filter light absorbing dyes, anti-bacterial agents, polymer latex, heavy metals, antistatic agents, matting agents Etc. can be contained as required.

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

  Table 1 below shows the types of compounds and the locations described in these three research disclosures.

〔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. Excellent in preventing dirt. As an electrode manufacturing method, an existing method such as an evaporation method, a printing method, an ink jet method, a spin coating method, or a CVD method can be used.

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

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

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

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

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

[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.

<Production of electrode>
(Production of electrode 1)
A commercially available glass with an ITO film (glass thickness of 1.5 mm) was etched by a known method to form an electrode having a pitch of 145 μm and an electrode width of 130 μm.

(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 glass substrate having a thickness of 1.5 mm and a size of 10 cm × 10 cm using a known method.

(Preparation of electrode 3)
A titanium dioxide dispersion (Ti-Nanoxide HT-L, manufactured by Solaronix) was screen-printed on the electrode 1, dried and baked in an oven at 120 ° C. to obtain an electrode 3 having a titanium dioxide film having a thickness of about 3 μm. .

(Preparation of electrode 3a)
A solution in which 0.1 parts by mass of the exemplified compound (M-23) is dissolved in 2 parts by mass of dimethyl sulfoxide is prepared. The electrode 3 is immersed in this solution and left for 8 hours, then pulled up and air-dried, and the exemplified compound (M- 23) obtained an observation-side electrode 3a adsorbed on the porous layer. In addition, when producing the display element, when using the observation side electrode 3a, it is defined that the exemplary compound (M-23) exists in the electrochromic medium.

(Preparation of electrode 3b)
A solution in which 0.1 part by mass of the exemplified compound (M-39) is dissolved in 2 parts by mass of dimethyl sulfoxide is prepared. 39) obtained an observation-side electrode 3b adsorbed on the porous layer. In addition, when producing the display element, when using the observation side electrode 3b, it is defined that the exemplary compound (M-39) exists in the electrochromic medium.

(Preparation of electrode 3c)
A solution in which 0.1 parts by mass of the exemplified compound (M-63) was dissolved in 2 parts by weight of dimethyl sulfoxide was prepared. 63) obtained an observation side electrode 3c adsorbed to the porous layer. Note that when the observation-side electrode 3c is used in manufacturing the display element, the exemplary compound (M-63) is defined as existing in the electrochromic medium.

(Preparation of electrode 3d)
A solution in which 0.1 parts by mass of the exemplified compound (M-22) is dissolved in 2 parts by mass of dimethyl sulfoxide is prepared. 22) obtained an observation side electrode 3d adsorbed on the porous layer. In addition, when producing the display element, when using the observation side electrode 3a, it is defined that exemplary compound (M-22) exists in an electrochromic medium.

(Preparation of electrode 3e)
A solution in which 0.1 parts by mass of the exemplified compound (M-42) is dissolved in 2 parts by mass of dimethyl sulfoxide is prepared. 42) obtained an observation-side electrode 3e adsorbed on the porous layer. Note that when the observation-side electrode 3e is used in manufacturing the display element, the exemplary compound (M-42) is defined as existing in the electrochromic medium.

(Preparation of electrode 3f)
A solution in which 0.1 part by mass of the exemplified compound (M-62) was dissolved in 2 parts by mass of dimethyl sulfoxide was prepared. 62) obtained an observation-side electrode 3f adsorbed on the porous layer. Note that when the observation-side electrode 3f is used in manufacturing the display element, the exemplary compound (M-62) is defined to be present in the electrochromic medium.

(Preparation of electrode 4)
A titanium dioxide dispersion (Ti-Nanoxide HT / SP manufactured by Solaronix) was screen-printed on the electrode 1 and baked in an oven at 120 ° C. to obtain an electrode 4 on which a titanium dioxide film having a thickness of about 5 μm was formed.

(Preparation of electrode 4a)
A solution in which 0.1 parts by mass of the exemplified compound (M-105) is dissolved in 2 parts by mass of dimethyl sulfoxide is prepared. 105) was obtained on the non-observation side electrode 4a adsorbed on the porous layer. Note that when the non-observation side electrode 4a is used in the manufacture of the display element, the exemplary compound (M-105) is defined to be present in the electrochromic medium.

(Preparation of electrode 4b)
A solution in which 0.1 part by mass of the exemplified compound (M-151) is dissolved in 2 parts by mass of dimethyl sulfoxide is prepared. 151) obtained the non-observation side electrode 4b adsorbed to the porous layer. Note that when the non-observation-side electrode 4b is used in manufacturing the display element, the exemplary compound (M-151) is defined as existing in the electrochromic medium.

(Preparation of electrode 5)
A titanium dioxide dispersion (Ti-Nanoxide D / SP manufactured by Solaronix) was screen-printed on the electrode 2 and baked in an oven at 120 ° C. to obtain an electrode 5 on which a titanium dioxide film having a thickness of about 5 μm was formed.

(Preparation of electrode 5a)
A solution in which 0.1 parts by mass of the exemplified compound (M-104) is dissolved in 2 parts by mass of dimethyl sulfoxide is prepared. The electrode 5 is immersed in this solution and left for 8 hours, then pulled up and air-dried, and the exemplified compound (M- 104) was obtained on the non-observation side electrode 5a adsorbed on the porous layer. Note that when the non-observation side electrode 5a is used in manufacturing the display element, the exemplary compound (M-104) is defined to be present in the electrochromic medium.

(Preparation of electrode 5b)
A solution in which 0.1 part by mass of the exemplified compound (M-151) is dissolved in 2 parts by mass of dimethyl sulfoxide is prepared. The electrode 5 is immersed in this solution and left for 8 hours, then pulled up and air-dried to give the exemplified compound (M- 151) obtained the non-observation side electrode 5b adsorbed to the porous layer. Note that when the non-observation side electrode 5b is used in manufacturing the display element, the exemplary compound (M-151) is defined to be present in the electrochromic medium.

(Preparation of electrode 5c)
A solution in which 0.1 part by mass of the exemplified compound (M-152) is dissolved in 2 parts by mass of dimethyl sulfoxide is prepared. 152) was obtained on the non-observation side electrode 5c adsorbed on the porous layer. Note that when the non-observation side electrode 5c is used in manufacturing the display element, the exemplary compound (M-152) is defined to be present in the electrochromic medium.

(Preparation of electrode 5d)
A solution in which 0.1 parts by mass of the exemplified compound (M-97) is dissolved in 2 parts by mass of dimethyl sulfoxide is prepared. The electrode 5 is immersed in this solution and left for 8 hours, then pulled up and air-dried. 97) was obtained on the non-observation side electrode 5d adsorbed to the porous layer. Note that when the non-observation-side electrode 5d is used in manufacturing the display element, the exemplary compound (M-97) is defined to be present in the electrochromic medium.

(Preparation of electrode 5e)
A solution in which 0.1 part by mass of the exemplified compound (M-105) is dissolved in 2 parts by mass of dimethyl sulfoxide is prepared. 105) was obtained on the non-observation side electrode 5e adsorbed on the porous layer. Note that when the non-observation-side electrode 5e is used in manufacturing the display element, the exemplary compound (M-105) is defined to be present in the electrochromic medium.

<< Preparation of electrochromic medium >>
(Preparation of electrochromic medium 1)
5 parts by mass of N-methylpyrrolidone, 1 part by mass of exemplary compound (A-9) as an electrochromic compound, 0.26 parts by mass of triphenylphosphine (hereinafter abbreviated as TPP), (nC ₄ H ₉ ) ₄ NClO ₄ (hereinafter referred to as “electrolyte 1”) was dissolved in 0.08 part by mass, and 5 parts by mass of polyvinylidene fluoride was further mixed and dissolved by heating to prepare an electrochromic medium 1.

(Preparation of electrochromic medium 2)
In the preparation of the electrochromic medium 1, 0.05 parts by mass of the N-oxyl compound (TEMPO) as the exemplary compound (M-9) was added and dissolved before adding and dissolving the polyvinylidene fluoride. Thus, an electrochromic medium 2 was prepared.

(Preparation of electrochromic medium 3)
In the preparation of the electrochromic medium 2, an electrochromic medium 3 was prepared in the same manner except that the exemplary compound (M-33) was used instead of the exemplary compound (M-9).

(Preparation of electrochromic medium 4)
In the preparation of the electrochromic medium 2, 0.26 parts by mass of TPP is changed to 0.35 parts by mass of triphenylantimony (hereinafter abbreviated as TPA), and the exemplary compound (M-9) is converted into an exemplary compound (M-9). M-84), and further, electrochromic medium 4 was prepared in the same manner except that 0.18 parts by mass of 2,5-di-t-amylbenzoquinone, which is exemplary compound (2-1), was added. .

(Preparation of electrochromic medium 5)
In the preparation of the electrochromic medium 2, the exemplary compound (A-9), which is an electrochromic compound, was changed to the same amount of the exemplary compound (A-10), and 0.26 parts by mass of TPP was changed to 0.2% by mass of TPA. The electrochromic medium 5 was prepared in the same manner except that the amount was changed to 35 parts by mass and the example compound (M-9) was changed to the same amount of the example compound (M-100).

(Preparation of electrochromic medium 6)
In the preparation of the electrochromic medium 2, 0.26 parts by mass of TPP was changed to 0.31 parts by mass of triphenylarosine (hereinafter abbreviated as TPAN), and the exemplified compound (M-9) was further added. An electrochromic medium 6 was prepared in the same manner except that the amount was changed to 2,3,5-triphenyltetrazolium bromide (hereinafter abbreviated as Compound II).

(Preparation of electrochromic medium 7)
In the preparation of the electrochromic medium 6, 0.31 part by mass of TPAN was changed to 0.44 part by mass of triphenylbismuth (hereinafter abbreviated as TPBi), and the compound II was replaced with the same amount of 1,3,5- An electrochromic medium 7 was prepared in the same manner except that it was changed to triphenylformazan (hereinafter abbreviated as compound III).

(Preparation of electrochromic medium 8)
As an electrochromic compound, 5 parts by mass of N-methylpyrrolidone, 0.5 parts by mass of the following compound I, 0.09 parts by mass of TPA, 0.08 parts by mass of electrolyte 1, 2 which is the exemplified compound (2-1) , 5-di-t-amylbenzoquinone and 0.18 parts by mass of Exemplified Compound (M-98) are added and dissolved, and 5 parts by mass of polyvinylidene fluoride are mixed and dissolved by heating. Electrochromic medium 8 was prepared.

(Preparation of electrochromic medium 9)
In the preparation of the electrochromic medium 8, an electrochromic medium 9 was prepared in the same manner except that 0.05 part by mass of the exemplified compound (M-9) was added.

(Preparation of electrochromic medium 10)
5 parts by mass of dimethyl sulfoxide, 0.5 parts by mass of the above compound I as an electrochromic compound, 0.09 parts by mass of TPA, and 0.05 parts by mass of tetrabutylammonium perchloride (hereinafter referred to as electrolyte 2) 0.04 parts by mass of compound (M-33) and 0.04 parts by mass of exemplary compound (M-98) are added and dissolved, and 2 parts by mass of polyvinylpyrrolidone (PVP, average molecular weight 100,000) is added thereto. And dissolved by heating to prepare an electrochromic medium 10.

(Preparation of electrochromic medium 11)
5 parts by mass of dimethyl sulfoxide, 0.8 parts by mass of exemplary compound (A-2) as an electrochromic compound, 0.25 parts by mass of TPP, 0.05 parts by mass of electrolyte 2, 9-methylacridine (hereinafter referred to as compound) 0.05 parts by mass of (abbreviated as IV) was added and dissolved, and 2 parts by mass of polyvinylpyrrolidone (PVP, average molecular weight 100,000) was added and dissolved by heating to prepare an electrochromic medium 11.

(Preparation of electrochromic medium 12)
5 parts by mass of dimethyl sulfoxide, 0.8 parts by mass of the exemplary compound (A-5) as an electrochromic compound, 0.25 parts by mass of TPP, 0.05 parts by mass of electrolyte 2, 1-hydroxyphenazine (hereinafter referred to as compound) 0.05 parts by mass of (abbreviated as V) and 0.2 parts by mass of the exemplified compound (2-7) are added and dissolved, and 2 parts by mass of polyvinylpyrrolidone (PVP, average molecular weight 100,000) is added thereto and heated. It melt | dissolved and the electrochromic medium 12 was prepared.

(Preparation of electrochromic medium 13)
As an electrochromic compound, 5 parts by mass of dimethyl sulfoxide, 0.8 parts by mass of exemplary compound (A-11), 0.25 parts by mass of TPP, 0.05 part by mass of electrolyte 2, and exemplary compound (M-9) 0.05 parts by mass was added and dissolved, and 2 parts by mass of polyvinylpyrrolidone (PVP, average molecular weight 100,000) was dissolved by heating to prepare an electrochromic medium 13.

(Preparation of electrochromic medium 14)
As an electrochromic compound, 5 parts by mass of dimethyl sulfoxide, 0.8 parts by mass of exemplary compound (A-1), 0.30 parts by mass of TPA, spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate (hereinafter, 0.05 part by mass of electrolyte 3), 0.05 part by mass of exemplary compound (M-33), and 0.2 part by mass of exemplary compound (3-1) are added and dissolved. 2 parts by mass of PVP (average molecular weight 100,000) was added and dissolved by heating to prepare an electrochromic medium 14.

(Preparation of electrochromic medium 15)
In the preparation of the electrochromic medium 14, the exemplified compound (A-1) is changed to the same amount of the exemplified compound (A-3) as the electrochromic compound, and the exemplified compound (M-33) is changed to the same amount of the exemplified compound (M The electrochromic medium 15 was prepared in the same manner except that it was changed to -84).

(Preparation of electrochromic medium 16)
0.8 parts by mass of the exemplary compound (A-6) as an electrochromic compound, 0.30 parts by mass of TPP, and 0.05 parts by mass of electrolyte 3 are added and dissolved in 5 parts by mass of dimethyl sulfoxide. 2 parts by mass of (PVP, average molecular weight 100,000) was added and dissolved by heating to prepare an electrochromic medium 16.

(Preparation of electrochromic medium 17)
To 5 parts by mass of dimethyl sulfoxide, 0.8 parts by mass of exemplary compound (A-12) as an electrochromic compound, 0.30 parts by mass of TPP, 0.05 parts by mass of electrolyte 3, and exemplary compound (2-1) 0.14 parts by mass was added and dissolved, and 2 parts by mass of polyvinyl pyrrolidone (PVP, average molecular weight 100,000) was added and dissolved by heating to prepare an electrochromic medium 17.

(Preparation of electrochromic medium 18)
As an electrochromic compound, 0.8 parts by mass of exemplary compound (A-1), 0.30 parts by mass of TPA, 0.05 parts by mass of electrolyte 2, and exemplary compound (M-152) are added to 5 parts by mass of dimethyl sulfoxide. 0.05 part by mass was added and dissolved, and 2 parts by mass of polyvinyl pyrrolidone (PVP, average molecular weight 100,000) was added thereto and dissolved by heating to prepare an electrochromic medium 18.

(Preparation of electrochromic medium 19)
In the preparation of the electrochromic medium 18, the exemplified compound (A-1) was changed to the same amount of the exemplified compound (A-3) as the electrochromic compound, and instead of the exemplified compound (M-152), the same amount of 4, An electrochromic medium 19 was prepared in the same manner except that 6-bis (diphenylphosphino) phenoxazine (hereinafter abbreviated as Compound VI) was used.

(Preparation of electrochromic medium 20)
As an electrochromic compound, 5 parts by mass of dimethyl sulfoxide, 0.8 parts by mass of exemplary compound (A-6), 0.30 parts by mass of TPP, 0.05 part by mass of electrolyte 2, and exemplary compound (2-1) 0.14 parts by mass was added and dissolved, and 2 parts by mass of polyvinyl pyrrolidone (PVP, average molecular weight 100,000) was added and dissolved by heating to prepare an electrochromic medium 20.

(Preparation of electrochromic medium 21)
In the preparation of the electrochromic medium 20, the exemplary compound (A-6) was changed to the same amount of the exemplary compound (A-11) as the electrochromic compound, and the exemplary compound (2-1) was removed in the same manner. An electrochromic medium 21 was prepared.

(Preparation of electrochromic medium 22)
5 parts by mass of dimethyl sulfoxide, 0.8 parts by mass of exemplary compound (A-1) as an electrochromic compound, 0.30 parts by mass of TPA, 0.05 parts by mass of electrolyte 3, and 0.04 parts by mass of compound II After adding 0.14 parts by weight of Example Compound (2-7) and dissolving, 2 parts by weight of polyvinylpyrrolidone (PVP, average molecular weight 100,000) is added and dissolved by heating. 0.25 μm) was added and dispersed to prepare an electrochromic medium 22.

(Preparation of electrochromic medium 23)
Exemplified compound (A-3) as an electrochromic compound (5 parts by mass), 0.8 parts by mass, TPA (0.30 parts by mass), electrolytic solution 3 (0.05 parts by mass), and exemplified compound (M-146) 0.04 parts by mass, 0.14 parts by mass of the exemplified compound (2-7) was added and dissolved, and then 2 parts by mass of polyvinylpyrrolidone (PVP, average molecular weight 100,000) was added and dissolved by heating. 2.5 parts by mass of titanium (average particle size: 0.25 μm) was added and dispersed to prepare an electrochromic medium 23.

(Preparation of electrochromic medium 24)
5 parts by mass of dimethyl sulfoxide, 0.8 parts by mass of exemplary compound (A-6) as an electrochromic compound, 0.30 parts by mass of TPP, 0.05 parts by mass of electrolyte 3, and 0.02 parts by mass of ferrocene After addition and dissolution, 2 parts by mass of polyvinyl pyrrolidone (PVP, average molecular weight 100,000) is added and dissolved by heating, and 2.5 parts by mass of titanium dioxide (average particle size 0.25 μm) is added and dispersed therein. An electrochromic medium 24 was prepared.

(Preparation of electrochromic medium 25)
As an electrochromic compound, 5 parts by mass of dimethyl sulfoxide, 0.8 parts by mass of exemplary compound (A-12), 0.30 parts by mass of TPP, 0.05 parts by mass of electrolytic solution 3, and exemplary compound (M-33) 0.04 parts by mass and 0.14 parts by mass of the exemplified compound (3-1) were added and dissolved, and then 2 parts by mass of polyvinylpyrrolidone (PVP, average molecular weight 100,000) was added and dissolved by heating. An electrochromic medium 25 was prepared by adding and dispersing 2.5 parts by mass of titanium (average particle size: 0.25 μm).

(Preparation of electrochromic medium 26)
As an electrochromic compound, 0.8 parts by mass of the exemplary compound (A-1), 0.30 parts by mass of TPA, 0.05 parts by mass of the electrolytic solution 2, and the exemplary compound (M-33) as 5 parts by mass of dimethyl sulfoxide 0.04 parts by mass of and dissolved, 2 parts by mass of polyvinyl pyrrolidone (PVP, average molecular weight 100,000) was added and dissolved by heating, and 2.5 mass of titanium dioxide (average particle size 0.25 μm) was added thereto. Part of the mixture was added and dispersed to prepare an electrochromic medium 26.

(Preparation of electrochromic medium 27)
After adding and dissolving 0.8 parts by mass of the exemplary compound (A-3) as an electrochromic compound, 0.30 parts by mass of TPA and 0.05 parts by mass of the electrolytic solution 2 in 5 parts by mass of dimethyl sulfoxide, polyvinylpyrrolidone 2 parts by mass of (PVP, average molecular weight 100,000) was added and dissolved by heating, and 2.5 parts by mass of titanium dioxide (average particle size of 0.25 μm) was added and dispersed therein to prepare an electrochromic medium 27. .

(Preparation of electrochromic medium 28)
As an electrochromic compound, 0.8 parts by mass of the exemplary compound (A-6), 0.30 parts by mass of TPP, 0.05 parts by mass of the electrolytic solution 2, and the exemplary compound (3-1) as 5 parts by mass of dimethyl sulfoxide After adding 0.2 parts by mass and dissolving, 2 parts by mass of polyvinylpyrrolidone (PVP, average molecular weight 100,000) was added and dissolved by heating, and 2.5 mass of titanium dioxide (average particle size of 0.25 μm) was added thereto. Part of the mixture was added and dispersed to prepare an electrochromic medium 28.

(Preparation of electrochromic medium 29)
As an electrochromic compound, 0.8 parts by mass of the exemplary compound (A-11), 0.30 parts by mass of TPP, 0.05 parts by mass of the electrolytic solution 2, and the exemplary compound (3-1) as 5 parts by mass of dimethyl sulfoxide After adding 0.2 parts by mass and dissolving, 2 parts by mass of polyvinylpyrrolidone (PVP, average molecular weight 100,000) was added and dissolved by heating, and 2.5 mass of titanium dioxide (average particle size of 0.25 μm) was added thereto. Part of the mixture was added and dispersed to prepare an electrochromic medium 29.

  In addition, the detail of each additive described by the abbreviation in Table 2 is as follows.

<Compound represented by formula (1)>
TPP: Triphenylphosphine TPA: Triphenylantimony TPAN: Triphenylasine TPBi: Triphenylbismuth <Electrolyte>
Electrolyte _{1: (n-C 4 H} 9) 4 NClO 4
Electrolyte 2: Tetrabutylammonium perchloride Electrolyte 3: Tetrafluoroborate spiro- (1,1 ′)-bipyrrolidinium <Reduction reaction type compound>
Compound II: 2,3,5-triphenyltetrazolium bromide Compound III: 1,3,5-triphenylformazan Compound IV: 9-methylacridine Compound V: 1-hydroxyphenazine Compound VI: 4,6-bis (diphenylphos Fino) phenoxazine << Preparation of display element >>
[Production of Display Element 1]
The electrode 1 is used as the observation side electrode, and the same electrode 1 is used as the non-observation side electrode. The electrodes are arranged so as to face each other at right angles, and the periphery of one electrode 1 is made of glass having an average particle size of 30 μm. An empty cell was prepared by trimming with an olefin-based sealant containing 10% of a spherical bead-shaped spacer as a volume fraction, and bonding electrodes 1 together and heating and pressing. The electrochromic medium 1 prepared above was vacuum-injected into this empty cell, and the injection port was sealed with an epoxy-based ultraviolet curable resin, whereby the display element 1 was produced.

[Production of Display Elements 2 to 29]
In the production of the display element 1, display elements 2 to 29 were produced in the same manner except that the types of the observation side electrode and the non-observation side electrode and the type of the electrochromic medium were changed as shown in Table 2.

<< Evaluation of display element >>
Using each of the produced display elements, measurement of drive voltage (V) and evaluation of memory properties and repeated durability were performed according to the following method.

[Measurement of drive voltage]
A test pattern display circuit was connected to each display element, the voltage application time was fixed to 0.5 seconds, and the drive voltage was measured by changing the voltage stepwise.

  The display elements 1 to 21 measure the transmittance at the peak color wavelength of the electrochromic compound, and the display elements 22 to 29 measure the reflectance with a spectrocolorimeter CM-3700d manufactured by Konica Minolta Sensig Co., Ltd. The voltage at which the transmittance or reflectance of the colored portion is saturated was defined as the driving voltage.

[Evaluation of memory]
The driving voltage obtained by measuring the driving voltage is applied to each display element for 0.5 seconds, and after displaying the pattern on the display element, the voltage application is stopped immediately, the circuit is disconnected, and the same method as above The change in transmittance or reflectance was followed. The first hour is measured every 3 minutes, up to 6 hours every 15 minutes, up to one day every hour, and then every 3 hours. The time required for the drop to 70% or less was determined, and this was used as a measure of memory properties.

×: Decrease in less than 1 hour Δ: Decrease in 1 hour or more and less than 24 hours ○: Decrease in 24 hours or more and less than 72 hours ◎: No decrease is observed even in 72 hours or more [Evaluation of repeated driving resistance]
For each display voltage, 0.5 seconds of color development, 1 second of blank, and 0.5 seconds of erasing drive (the opposite polarity is applied at the same voltage as color development) for each drive voltage as one cycle The driving operation was repeated and repeated resistance was evaluated. The number of times of repeated driving was evaluated when the transmittance or reflectance of the colored portion became 70% or less of the initial value.

×: Decrease when the repeat count is less than 300 Δ: Decrease when the repeat count is 300 or more and less than 1000 ○: Decrease when the repeat count is 1000 or more and less than 3000 ◎: Even if the repeat count is 3000 or more Table 3 shows the results obtained as described above.

  As is apparent from the results shown in Table 3, it can be seen that the display element of the present invention has a lower driving voltage, a memory property, and an excellent repeated driving resistance of the display element than the comparative example.

Claims (10)

In a display element containing an electrochromic medium between at least a pair of opposing electrodes, the electrochromic medium includes an oxidation coloring electrochromic compound, a compound represented by the following general formula (1), an electrolyte, and a redox reaction type A display element comprising a compound.

[Wherein M ₁ is an element belonging to Group 15 of the periodic table and does not contain nitrogen. R ₁ , R ₂ and R ₃ each represent an aryl group having a substituent or an aryl group having no substituent, and may be the same or different from each other. ] The display element according to claim 1, wherein the oxidative coloring electrochromic compound is a compound having a structure represented by the following general formula (A).

[Wherein, X represents a carbon atom or a nitrogen atom, and R ₄ and R ₅ each represents a substituted or unsubstituted aromatic group, a group having a substituted or unsubstituted heterocyclic ring, or a fluoran group. R ₄ and R ₅ may form part of the fluorane skeleton. R ₆ represents a hydrogen atom, a halogen atom, a substituted or unsubstituted acyl group, an alkyl group, an alkoxy group, a nitro group, an aryl group, or an amino group, respectively. ] The display element according to claim 1, wherein the electrochromic medium further contains a compound represented by the following general formula (2) or general formula (3).

[Wherein, R ₇ , R ₈ , R ₉ and R ₁₀ each represent a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group or an alkoxycarbonyl group. R ₇ , R ₈ , R ₉ and R ₁₀ are not all hydrogen atoms at the same time. Adjacent R ₇ and R ₈ may be condensed with each other to form a 5-membered or 6-membered condensed ring. Adjacent R ₉ and R ₁₀ may be condensed with each other to form a 5-membered or 6-membered condensed ring. ]

(In the formula, R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ each represent a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group or an alkoxycarbonyl group. R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ are all Are not simultaneously hydrogen atoms, either adjacent R ₁₁ and R ₁₂ , or adjacent R ₁₃ and R ₁₄ , one or both form a condensed ring, adjacent R ₁₁ and R ₁₂ , or When one of adjacent R ₁₃ and R ₁₄ forms a condensed ring, the other two groups are both hydrogen atoms, and the condensed ring is a 5-membered or 6-membered ring.]   4. The display element according to claim 1, wherein the electrochromic medium includes an oxidation reaction type compound and a reduction reaction type compound as the oxidation reduction reaction type compound. 5.   The oxidation reaction type compound is an N-oxyl derivative, an N-hydroxyphthalimide derivative, a compound having an N—O bond of a hydroxamic acid derivative, or a compound having an allyloxy free group having a bulky substituent introduced at the O-position of galvinoxyl. The display element according to claim 4, wherein the display element is at least one selected.   The reduction-reactive compound is at least one selected from ethanedione or a derivative thereof, tetrazolium salt, formazan or a derivative thereof, phenazine or a derivative thereof, phenoxazine or a derivative thereof, and acridine or a derivative thereof. 4. The display element according to 4.   The display element according to claim 1, wherein at least one electrode surface of the pair of opposing electrodes has a nanoporous layer.   The display element according to claim 7, wherein, among the nanoporous layers, a nanoporous layer provided on an observation-side electrode surface immobilizes the oxidation reaction type compound.   The display element according to claim 7, wherein, among the nanoporous layers, a nanoporous layer provided on a non-observation side electrode surface immobilizes the reduction reaction type compound.   The display device according to claim 1, wherein the electrochromic medium includes a white scatterer.