JPWO2009063714A1 - Display element - Google Patents

Abstract

The present invention provides a novel electrochemical display element capable of realizing bright white display, high contrast, and full color display excellent in light resistance with a simple member configuration. This display element includes an electrolyte, an electrochromic compound, and a compound having a singlet oxygen quenching rate (kq) of 10 5 or more and 10 10 or less between opposing electrodes.

Description

  The present invention relates to a novel electrochemical display element.

  In recent years, with the increase in the operating speed of personal computers, the spread of network infrastructure, the increase in capacity and price of data storage, etc., information such as documents and images conventionally provided in printed materials such as paper has become easier. Opportunities for obtaining and browsing electronic information are increasing.

  As a means for browsing such electronic information, conventional liquid crystal displays and CRTs (CRTs), and in recent years, light-emitting types such as organic electroluminescence displays are mainly used. In particular, when electronic information is document information, It is necessary to keep an eye on this browsing means for a relatively long time, and these actions are hardly human-friendly means. Generally, as a disadvantage of light-emitting displays, eyes flicker due to flickering, inconvenient to carry, and attitude to read However, it is necessary to adjust the line of sight to the still screen, and problems such as increased power consumption when read for a long time are known.

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

  That is, the method using a polarizing plate such as a reflective liquid crystal has a low reflectance of about 40% and is difficult to display white, and many of the production methods used for producing the constituent members are not easy. In addition, the polymer dispersed liquid crystal requires a high voltage and utilizes the difference in refractive index between organic substances, so that the resulting image has insufficient contrast. In addition, the polymer network type liquid crystal has problems such as a high voltage and a complicated TFT circuit required to improve the memory performance. In addition, a display element based on electrophoresis requires a high voltage of 10 V or more, and there is a concern about durability due to electrophoretic particle aggregation. As a method for performing color display using these methods, a method using a color filter is known. In principle, the former has a problem that a bright white display cannot be obtained due to coloring of the color filter.

  An electrochromic display element (hereinafter abbreviated as EC method) is known as a display method that eliminates the drawbacks of each of the above-described methods. The EC method is capable of full color display at a low voltage of 3 V or less, has advantages such as a simple cell configuration and excellent white quality, and various methods have been disclosed (for example, see Patent Documents 1 and 2). .

As a result of examining the techniques disclosed in each of the above-mentioned patent documents in detail, the inventor of the present invention has a decrease in contrast when the display element is left under sunlight or a fluorescent lamp (hereinafter referred to as light resistance). It turns out that there is a problem to do. As means for solving the light resistance, for example, a technique using an ultraviolet absorber as described in Patent Document 3 has been studied, but the improvement in the light resistance of the display element is never satisfactory. I knew it was n’t.
WO2004 / 068231 Specification WO 2004/066773 specification JP 2006-301268 A

  The present invention has been made in view of the above problems, and has as its object a novel electrochemical technique capable of realizing a bright white display, high contrast, and full color display excellent in light resistance with a simple member configuration. It is to provide a display element.

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

1. A display element comprising an electrolyte, an electrochromic compound, and a compound having a singlet oxygen quenching rate (kq) of 10 ⁵ or more and 10 ¹⁰ or less between opposing electrodes.

2. 2. The display according to 1 above, wherein the compound having a singlet oxygen quenching rate (kq) of 10 ⁵ or more and 10 ¹⁰ or less is a compound represented by the following general formula [1] or [2] element.

[Wherein, R ₁ represents an aryl group or a heterocyclic group, and Z ₁ and Z ₂ each represent an alkylene group having 1 to 3 carbon atoms. However, the sum total of carbon number of the alkylene group represented by Z < ₁ > and Z < ₂ > is 3-6. A represents an oxygen atom, NZ ₃ , S (O) _n , and Z ₃ represents an alkyl group or an aryl group. n represents an integer of 0 to 2. ]

[Wherein R ₂ represents an alkyl group or a trialkylsilyl group, and R ₃ , R ₄ , R ₅ , R ₆ and R ₇ are each a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, An alkenyl group, an alkenyloxy group, an acylamino group, a halogen atom, an alkylthio group, an arylthio group, an alkoxycarbonyl group, an acyloxy group, an acyl group, or a sulfonamide group is represented. Two groups out of R _{2 to} R ₇ may be linked to form a 5- to 6-membered ring. ]
3. 3. The display element according to 1 or 2 above, which contains a compound represented by the following general formula [3] between the counter electrodes.

[Wherein R ₈ , R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are each a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an alkenyl group, an alkenyloxy group, an acylamino group, a halogen atom, An alkylthio group, an arylthio group, an alkoxycarbonyl group, an acyloxy group, an acyl group, or a sulfonamide group is represented. Two groups may form a 5- or 6-membered ring by combining one of R ₈ to R _12. However, neither R ₈ nor R ₁₂ is an alkyl group. ]
4). 4. The display element according to any one of 1 to 3, wherein the electrochromic compound is a compound represented by the following general formula (A).

[Wherein, R ¹ represents a substituted or unsubstituted aryl group, and R ² and R ³ each represent a hydrogen atom or a substituent. X represents> N—R ⁴ , an oxygen atom or a sulfur atom, and R ⁴ represents a hydrogen atom or a substituent. ]
5. 5. The display element according to any one of 1 to 4, wherein a singlet oxygen quenching rate (kq) of the compound is 10 ⁶ or more and 10 ⁸ or less.

  6). 6. The display element according to any one of 1 to 5, wherein at least one of the counter electrodes has a porous layer containing a metal oxide.

  7. 7. The display element according to 6 above, wherein the metal oxide is at least one selected from titanium dioxide, zinc oxide, and tin oxide.

  8). 8. The display element according to 6 or 7 above, wherein the electrochromic compound is immobilized on a porous layer containing the metal oxide.

  9. 9. The display element according to any one of 6 to 8, wherein the compound represented by the general formula (A) has a group that adsorbs to the metal oxide.

10. The group adsorbing to the metal oxide is —COOH, —P═O (OH) ₂ , —OP═O (OH) ₂ or —Si (OR) ₃ (R represents an alkyl group). 10. The display element as described in 9 above.

  11 11. The display element according to any one of 1 to 10, wherein an N-oxyl derivative is held between the counter electrodes.

  12 12. The display element according to any one of 1 to 11, wherein the electrolyte contains a metal salt compound.

  13. 13. The display device as described in 12 above, wherein the metal salt compound is a silver salt compound.

  14 14. The display element according to any one of 1 to 13, wherein the electrolyte contains at least one selected from compounds represented by the following general formulas (I) and (II).

Formula (I)
R ⁵ -S-R ⁶
[Wherein, R ⁵ and R ⁶ each represents a substituted or unsubstituted hydrocarbon group. However, when a ring containing an S atom is formed, an aromatic group is not taken. ]

[Wherein, M represents a hydrogen atom, a metal atom or quaternary ammonium. Z represents a nitrogen-containing heterocyclic ring. n represents an integer of 0 to 5, and R ⁷ represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkylcarbonamide group, an arylcarbonamide group, an alkylsulfonamide group, an arylsulfonamide group, an alkoxy group, an aryloxy group Group, alkylthio group, arylthio group, alkylcarbamoyl group, arylcarbamoyl group, carbamoyl group, alkylsulfamoyl group, arylsulfamoyl group, sulfamoyl group, cyano group, alkylsulfonyl group, arylsulfonyl group, alkoxycarbonyl group, aryl Represents an oxycarbonyl group, an alkylcarbonyl group, an arylcarbonyl group, an acyloxy group, a carboxyl group, a carbonyl group, a sulfonyl group, an amino group, a hydroxy group or a heterocyclic group, and when n is 2 or more, each R ⁷ is They may be the same or different, and may be linked together to form a condensed ring. ]
15. 14. The display element according to any one of 1 to 13, wherein the electrolyte contains at least one selected from compounds represented by the following general formulas (III) and (IV).

[Wherein, L represents an oxygen atom or CH ₂ , and R ^{8 to} R ¹¹ each represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group, or an alkoxy group. ]

[Wherein, R ¹² and R ¹³ each represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group or an alkoxy group. ]

  According to the present invention, a novel electrochemical display element capable of realizing bright white display, high contrast, and full color display excellent in light resistance with a simple member configuration can be provided.

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

As a result of intensive studies in view of the above problems, the present inventor contains an electrolyte, an electrochromic compound, and a compound having a singlet oxygen quenching rate (kq) of 10 ⁵ or more and 10 ¹⁰ or less between the counter electrodes. It has been found that a novel electrochemical display element capable of realizing bright white display, high contrast, and full color display excellent in light resistance with a simple member configuration can be obtained by a display element characterized by It is up to the invention.

  Details of the present invention will be described below.

[Basic structure of display element]
In the display element of the present invention, the display portion is provided with one corresponding counter electrode. Between the counter electrodes, an electrolyte, a compound represented by the general formula (A) and at least one compound represented by the general formula (1) are contained. By applying positive and negative voltages between the counter electrodes of the display element of the present invention, the color state of the display element can be reversibly switched.

〔Electrolytes〕
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”).

[Electrochromic compound]
The electrochromic compound used in the display element of the present invention may be a compound that exhibits a phenomenon (electrochromism) in which the property of optical absorption (color and light transmittance) of a substance reversibly changes due to electrochemical redox. Any compound may be used. Specific compounds include "Electrochromic display" (June 28, 1991, Sangyo Tosho Co., Ltd.) pp27-124, "Development of chromic materials" (November 15, 2000, CMC Corporation) pp81 The compound described in -95 etc. can be mentioned.

(Compound represented by formula (A))
In the display device of the present invention, the compound represented by the general formula (A) that is suitably used as an electrochromic compound will be described.

In the general formula (A), R ¹ represents a substituted or unsubstituted aryl group, and R ² and R ³ each represent a hydrogen atom or a substituent. X represents> N—R ⁴ , an oxygen atom or a sulfur atom, and R ⁴ represents a hydrogen atom or a substituent.

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

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

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

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

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

[Compound having a singlet oxygen quenching rate (kq) of 10 ⁵ or more and 10 ¹⁰ or less]
One feature of the display element of the present invention is that it contains a compound having a singlet oxygen quenching rate (Kq) of 10 ⁵ or more and 10 ¹⁰ or less.

  The singlet oxygen referred to in the present invention is one of activated oxygen, and the compounds having the quenching action are extremely limited.

  As a mechanism for quenching singlet oxygen, there are a chemical quenching mechanism and a physical quenching mechanism, and a functional group having either mechanism can be used. The chemical quenching mechanism is a mechanism that consumes singlet oxygen through chemical reaction with singlet oxygen, and the physical quenching mechanism is a mechanism of singlet oxygen and electron such as a transition metal element. This is a mechanism for deactivating singlet oxygen in an excited state to triplet oxygen in a ground state by exchanging spins.

One characteristic of the display element of the present invention is that it contains a compound having a singlet oxygen quenching rate (Kq) of 10 ⁵ or more and 10 ¹⁰ or less, more preferably a singlet oxygen quenching rate (Kq). 10 ⁶ or more and 10 ⁸ or less. If the singlet oxygen quenching rate (Kq) is 10 ⁵ or more, it is sufficient as the ability to deactivate singlet oxygen, and if it is 10 ¹⁰ or less, the compound itself having the function of quenching singlet oxygen is sufficient. Lifespan can be maintained.

  As a method of evaluating the quenching function of these singlet oxygen quenchers, the method described in the 22nd Oxidation Reaction Discussion Summary p7 is known. The singlet oxygen quenching rate (kq) is determined by the above method. However, since the chemical quenching mechanism and the physical quenching mechanism cannot be measured separately, the sum of them can only be evaluated.

Specific examples of the compound having a singlet oxygen quenching rate (Kq) of 10 ⁵ or more and 10 ¹⁰ or less used in the present invention are shown below, but the singlet oxygen quenching rate (Kq) used in the present invention is shown below. However, the compounds in which is 10 ⁵ or more and 10 ¹⁰ or less are not limited thereto.

  As a result of investigating the cause of the decrease in contrast due to light resistance in the display element, the present inventors have activated oxygen in an electrode having photocatalytic properties such as titanium dioxide, and organic compounds including electrochromic compounds It was found that the main factor is to be decomposed.

  By adding the compound of the present invention to the electrolyte, it is possible to effectively quench the activated oxygen described above, thereby suppressing the decomposition of organic compounds including electrochromic compounds.

In the display element of the present invention, the compound having a singlet oxygen quenching rate (kq) of 10 ⁵ or more and 10 ¹⁰ or less may be a compound represented by the general formula [1] or [2]. preferable. Hereinafter, the compounds (antioxidants) represented by the general formulas [1] and [2] will be described.

(Compound represented by the general formula [1])
In the general formula [1], R ₁ represents an aryl group or a heterocyclic group, and Z ₁ and Z ₂ each represent an alkylene group having 1 to 3 carbon atoms. However, the sum total of carbon number of the alkylene group represented by Z < ₁ > and Z < ₂ > is 3-6. A represents an oxygen atom, NZ ₃ , S (O) _n , and Z ₃ represents an alkyl group or an aryl group. n represents an integer of 0 to 2.

Examples of the aryl group represented by R ₁ include a phenyl group and a 1-naphthyl group, and these aryl groups may have a substituent.

Examples of the heterocyclic group represented by R ₁ include a 2-furyl group and a 2-thienyl group.

Z ₁ and Z ₂ each represent an alkylene group having 1 to 3 carbon atoms, but the total of the alkylene groups represented by Z ₁ and Z ₂ is 3 to 6.

A represents an oxygen atom, NZ ₃ , or S (O) _n , and preferably S (O) _n . In addition, the alkyl group represented by Z ₃ represents, for example, a linear or branched alkyl group having 1 to 24 carbon atoms, and the rule group represents, for example, a phenyl group. It may have a substituent.

  n represents an integer of 0 to 2, and is preferably 2.

  Hereinafter, although the specific example of a compound (antioxidant) represented by General formula [1] is shown, this invention is not limited to these.

(Compound represented by the general formula [2])
In the general formula [2], R ₂ represents an alkyl group or a trialkylsilyl group. In the general formula [2], examples of R ₂ include an alkyl group (for example, methyl, ethyl, octyl, lauryl, etc.) or A trialkylsilyl group (for example, a dimethylpropylsilyl group etc.) is mentioned.

In the general formula [2], R ₃ , R ₄ , R ₅ , R ₆ and R ₇ are each a hydrogen atom, alkyl group, alkoxy group, aryl group, aryloxy group, alkenyl group, alkenyloxy group, acylamino group, A halogen atom, an alkylthio group, an arylthio group, an alkoxycarbonyl group, an acyloxy group, an acyl group, or a sulfonamide group is represented. In the general formula [2], examples of R ₃ , R ₄ , R ₅ , R ₆ and R ₇ are each a hydrogen atom, an alkyl group (for example, methyl, ethyl, octyl, lauryl, etc.), an alkoxy group (for example, Methoxy, ethoxy, butyloxy, octyloxy, etc.), aryl groups (eg, phenyl, naphthyl, etc.), aryloxy groups (eg, phenoxy, naphthoxy, etc.), alkenyl groups (eg, octenyl, etc.), alkenyloxy groups (eg, octyloxy) Tenyloxy etc.), acylamino groups (eg acetylamino, palmitoylamino, benzoylamino etc.), halogen atoms (eg chlorine, bromine etc.), alkylthio groups (eg octylthio, laurylthio etc.), arylthio groups (eg phenylthio) An alkoxycarbonyl group (eg, methoxycarbonyl , Ethoxycarbonyl, hexadecyloxycarbonyl, etc.), acyloxy groups (eg acetyloxy, benzoyloxy etc.), acyl groups (eg acetyl, valeryl, stearoyl, benzoyl etc.), sulfonamido groups (eg octylsulfonamide, lauryl) Sulfonamide and the like).

Two groups out of R _{2 to} R ₇ may be linked to form a 5- to 6-membered ring (for example, indane, spiroindane, chroman, spirochroman ring, etc.).

In the general formula [2], R ₄ and R ₆ are preferably not alkoxy groups.

  A preferable compound in the general formula [2] is a compound represented by the following general formula [2A] or general formula [2B].

In the general formula [2A], R _{13 to} R ₁₆ each represents an alkyl group.

In the general formula [2B], R _{17 to} R ₂₄ each represents an alkyl group.

  Specific examples of the compound represented by the general formula [2] are shown below, but the present invention is not limited thereto.

[Compound represented by the general formula [3]]
The display element of the present invention contains a compound represented by the general formula [3] together with an electrolyte, an electrochromic compound, and a compound having a singlet oxygen quenching rate (kq) of 10 ⁵ or more and 10 ¹⁰ or less. Is preferred.

In the general formula [3], R _{8 to} R ₁₂ are each a hydrogen atom, alkyl group, alkoxy group, aryl group, aryloxy group, alkenyl group, alkenyloxy group, acylamino group, halogen atom, alkylthio group, arylthio group, An alkoxycarbonyl group, an acyloxy group, an acyl group, or a sulfonamide group is represented. In the general formula [3], examples of R ₈ , R ₉ , R ₁₀ and R ₁₁ are each a hydrogen atom, an alkyl group (eg, methyl, ethyl, octyl, lauryl, etc.), an alkoxy group (eg, methoxy, ethoxy , Butyloxy, octyloxy, etc.), aryl groups (eg, phenyl, naphthyl, etc.), aryloxy groups (eg, phenoxy, naphthoxy, etc.), alkenyl groups (eg, octenyl, etc.), alkenyloxy groups (eg, octenyloxy, etc.) ), Acylamino groups (eg acetylamino, palmitoylamino, benzoylamino etc.), halogen atoms (eg chlorine, bromine etc.), alkylthio groups (eg octylthio, laurylthio etc.), arylthio groups (eg phenylthio), alkoxycarbonyl Groups (eg methoxycarbonyl, eth Xyloxycarbonyl, hexadecyloxycarbonyl, etc.), acyloxy groups (eg, acetyloxy, benzoyloxy, etc.), acyl groups (eg, acetyl, valeryl, stearoyl, benzoyl, etc.), sulfonamido groups (eg, octylsulfonamide, lauryl sulfone) Amide etc.).

In the general formula [3], R ₈ and R ₁₁ are not simultaneously alkyl groups.

  A preferable compound in the general formula [3] is a compound represented by the following general formula [3A].

In the general formula [3A], R _{25 to} R ₂₇ each represents an alkyl group.

  A more preferable compound is a compound represented by the following general formula [3B].

In the general formula [3B], R _{28 to} R ₃₁ each represents an alkyl group, and J represents an alkylene group which may have a branched chain.

  Although the typical example of a compound represented by General formula [3] is shown below, this invention is not limited to these.

  In the present invention, each of the above-described antioxidants is preferably added in the range of 0.1 to 10% by mass, more preferably 0.5 to 5% by mass, based on the total mass constituting the counter electrodes. -3 mass% is particularly preferred.

[Group adsorbing to metal oxide]
In the display element of the present invention, it is preferable that the compound represented by the general formula (A) according to the present invention has a group that adsorbs to a metal oxide (hereinafter abbreviated as an adsorptive group).

  The adsorptive group according to the present invention includes, for example, chemical adsorption and physical adsorption, and chemical adsorption is a relatively strong adsorption state due to a chemical bond with the electrode surface. Physical adsorption refers to the electrode surface and the adsorbing substance. It is a relatively weak adsorption state due to the van der Waals force acting between the two.

The adsorptive group according to the present invention is preferably a chemisorbable group. Examples of the adsorptive group to be chemisorbed include —COOH, —P—O (OH) ₂ , —OP═O (OH) ₂ and —Si (OR) ₃ (R represents an alkyl group) is preferred.

[Porous layer containing metal oxide]
In the display element of the present invention, it is preferable to use a porous layer containing a metal oxide.

  Examples of the metal oxide constituting the porous layer according to the present invention include titanium oxide, silicon oxide, zinc oxide, tin oxide, Sn-doped indium oxide (ITO), antimony-doped tin oxide (ATO), and fluorine-doped tin oxide. (FTO), aluminum-doped zinc oxide and the like, or a mixture thereof.

The porous layer is formed by binding or contacting a plurality of fine particles of the metal oxide. The average particle diameter of the metal oxide fine particles is preferably 5 nm to 10 μm, more preferably 20 nm to 1 μm. The specific surface area of the metal oxide fine particles is preferably ^{1 × 10 -3 ~1 × 10 2} m 2 / g by a simple BET method, more preferably at 1 × 10 ^-2 ~10m ² / g . In addition, the metal oxide fine particles may have any shape such as an indefinite shape, a needle shape, a spherical shape, or the like.

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

  In the present invention, the term “porous” means that a porous layer is disposed, a potential difference is applied between the counter electrodes, and an electrochromic compound oxidation-reduction reaction or metal dissolution precipitation reaction can be caused. The penetration state that can move in the electrode.

[N-oxyl derivative]
In the display element of the present invention, it is preferable to have an N-oxyl derivative between the counter electrodes.

  The N-oxyl derivative according to the present invention may function as a mediator of an electrodeposition reaction or an electrochromic reaction or may function as a counter electrode reactant. When functioning as a mediator, the electrodeposition reaction or the electrochromic reaction In the case of functioning as a counter electrode reactant, it is desirable to have an activity opposite to that of the electrodeposition reaction or electrochromic reaction.

  The N-oxyl derivative according to the present invention may be contained in the electrolyte or may be immobilized on the electrode surface. Examples of the method of immobilizing on the electrode surface include a method of introducing a group that chemically or physically adsorbs with the electrode surface into the N-oxyl derivative, a method of polymerizing the N-oxyl derivative to form a thin film on the electrode surface, and the like. It is done. The N-oxyl derivative may be added in the form of an N-oxyl radical or in the form of an N-hydroxy compound.

  Specific examples of the N-oxyl derivative according to the present invention are shown below, but the present invention is not limited only to these exemplified compounds.

[Compound represented by general formula (I) or general formula (II)]
In the display element of the present invention, the electrolyte contains at least one selected from the compounds represented by the general formulas (I) and (II). In the general formula (I), R ⁵ , R ⁶ Each represents a substituted or unsubstituted hydrocarbon group, which includes an aromatic straight chain or branched group. Further, these hydrocarbon groups may contain one or more nitrogen atoms, oxygen atoms, phosphorus atoms, sulfur atoms, and halogen atoms. However, when a ring containing an S atom is formed, an aromatic group is not taken.

  Examples of groups that can be substituted for the hydrocarbon group include amino groups, guanidino groups, quaternary ammonium groups, hydroxyl groups, halogen compounds, carboxylic acid groups, carboxylate groups, amide groups, sulfinic acid groups, sulfonic acid groups, and sulfates. Groups, phosphonic acid groups, phosphate groups, nitro groups, cyano groups and the like.

  Generally, in order to cause dissolution and precipitation of silver, it is necessary to solubilize silver in an electrolyte. For example, silver or a compound containing silver is solubilized by coexisting with a compound containing a chemical structural species that interacts with silver, such as a coordinate bond with silver and a weak covalent bond with silver. It is common to use a means for converting to. As the chemical structural species, halogen atoms, mercapto groups, carboxyl groups, imino groups and the like are known, but in the present invention, the thioether group is also useful as a silver solvent and has little influence on the coexisting compound, It is characterized by high solubility in solvents.

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

I-1: CH ₃ SCH ₂ CH ₂ OH
I-2: HOCH ₂ CH ₂ SCH ₂ CH ₂ OH
I-3: HOCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OH
I-4: HOCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OH
I-5: HOCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ OH
I-6: HOCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ OH
I-7: H ₃ CSCH ₂ CH ₂ COOH
I-8: HOOCCH ₂ SCH ₂ COOH
I-9: HOOCCH ₂ CH ₂ SCH ₂ CH ₂ COOH
I-10: HOOCCH ₂ SCH ₂ CH ₂ SCH ₂ COOH
I-11: HOOCCH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ COOH
I-12: HOOCCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH (OH) CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ COOH
_{I-13: HOOCCH 2 CH 2} SCH 2 CH 2 SCH 2 CH (OH) CH (OH) CH 2 SCH 2 CH 2 SCH 2 CH 2 COOH
I-14: H ₃ CSCH ₂ CH ₂ CH ₂ NH _{2
I-15: H 2 NCH 2} CH 2 SCH 2 CH 2 NH 2
I-16: H ₂ NCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NH _{2
I-17: H 3 CSCH 2} CH 2 CH (NH 2) COOH
_{I-18: H 2 NCH 2} CH 2 OCH 2 CH 2 SCH 2 CH 2 SCH 2 CH 2 OCH 2 CH 2 NH 2
_{I-19: H 2 NCH 2} CH 2 SCH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 SCH 2 CH 2 NH 2
I-20: H ₂ NCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NH ₂
I-21: HOOC (NH ₂ ) CHCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ CH (NH ₂ ) COOH
I-22: HOOC (NH ₂ ) CHCH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH (NH ₂ ) COOH
_{I-23: HOOC (NH 2} ) CHCH 2 OCH 2 CH 2 SCH 2 CH 2 SCH 2 CH 2 OCH 2 CH (NH 2) COOH
_{I-24: H 2 N (} O =) CCH 2 SCH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 SCH 2 C (= O) NH 2
_{I-25: H 2 N (} O =) CCH 2 SCH 2 CH 2 SCH 2 C (= O) NH 2
_{I-26: H 2 NHN (} O =) CCH 2 SCH 2 CH 2 SCH 2 C (= O) NHNH 2
_{I-27: H 3 C (} O =) NHCH 2 CH 2 SCH 2 CH 2 SCH 2 CH 2 NHC (= O) CH 3
I-28: H ₂ NO ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SO ₂ NH _{2
I-29: NaO 3 SCH 2} CH 2 CH 2 SCH 2 CH 2 SCH 2 CH 2 CH 2 SO 3 Na
_{I-30: H 3 CSO 2} NHCH 2 CH 2 SCH 2 CH 2 SCH 2 CH 2 NHO 2 SCH 3
I-31: H ₂ N (NH) CSCH ₂ CH ₂ SC (NH) NH ₂ .2HBr
I-32: H ₂ (NH) CSCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ SC (NH) NH ₂ .2HCl
I-33: H ₂ N (NH) CNHCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NHC (NH) NH ₂ .2HBr
I-34: [(CH ₃ ) ₃ NCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ N (CH ₃ ) ₃ ] 2 ⁺ · 2Cl ⁻

  Among the above-exemplified compounds, Exemplified Compound I-2 is particularly preferable from the viewpoint that the object and effects of the present invention can be exhibited.

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

In the general formula (II), M represents a hydrogen atom, a metal atom or quaternary ammonium. Z represents a nitrogen-containing heterocyclic ring excluding imidazole rings. n represents an integer of 0 to 5, and R ⁷ represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkylcarbonamide group, an arylcarbonamide group, an alkylsulfonamide group, an arylsulfonamide group, an alkoxy group, an aryloxy group Group, alkylthio group, arylthio group, alkylcarbamoyl group, arylcarbamoyl group, carbamoyl group, alkylsulfamoyl group, arylsulfamoyl group, sulfamoyl group, cyano group, alkylsulfonyl group, arylsulfonyl group, alkoxycarbonyl group, aryl Represents an oxycarbonyl group, an alkylcarbonyl group, an arylcarbonyl group, an acyloxy group, a carboxyl group, a carbonyl group, a sulfonyl group, an amino group, a hydroxy group or a heterocyclic group, and when n is 2 or more, each R ⁷ is They may be the same or different, and may be linked together to form a condensed ring.

Examples of the metal atom represented by M in the general formula (II) include Li, Na, K, Mg, Ca, Zn, and Ag. Examples of the quaternary ammonium include NH ₄ , N (CH ₃ ) ₄ , N (C ₄ H ₉ ) ₄ , N (CH ₃ ) ₃ C ₁₂ H ₂₅ , N (CH ₃ ) ₃ C ₁₆ H ₃₃ , N (CH ₃ ) ₃ CH ₂ C ₆ H _{5 and the} like It is done.

  Examples of the nitrogen-containing heterocycle represented by Z in the general formula (II) include a tetrazole ring, a triazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, an indole ring, an oxazole ring, a benzoxazole ring, and a benzimidazole ring. Benzothiazole ring, benzoselenazole ring, naphthoxazole ring and the like.

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

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

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

[Compound represented by general formula (III) or general formula (IV)]
In the display element of the present invention, the electrolyte preferably contains a compound represented by the general formula (III) or (IV).

  First, details of the compound represented by formula (III) will be described.

In the general formula (III), L represents an oxygen atom or CH ₂ , and R ^{8 to} R ¹¹ each represents 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.

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

  Next, details of the compound represented by formula (IV) will be described.

In the general formula (IV), R ¹² and R ¹³ 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.

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

  Among the compounds represented by the general formula (III) and the general formula (IV) exemplified above, the exemplified compounds (III-1), (IV-2) and (IV-3) are particularly preferable.

  The compounds represented by the general formulas (III) and (IV) according to the present invention are one kind of electrolyte solvents. 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.

[Metal salt compounds]
The metal salt compound according to the present invention is any compound as long as it contains a metal species that can be dissolved and precipitated by driving the counter electrode on at least one electrode on the counter electrode. There may be. Preferred metal species are silver, bismuth, copper, nickel, iron, chromium, zinc and the like, and particularly preferred are silver and bismuth.

[Silver salt compound]
The silver salt compound according to the present invention is silver or a compound containing silver in the chemical structure, such as silver oxide, silver sulfide, metallic silver, silver colloidal particles, silver halide, silver complex compound, silver ion and the like. There are no particular restrictions on the phase state species such as the solid state, the solubilized state in liquid, and the gas state, and the charged state species such as neutral, anionic, and cationic.

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

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

Formula (1)
0 ≦ [X] / [Metal] ≦ 0.1
The halogen atom as used in the field of this invention means an iodine atom, a chlorine atom, a bromine atom, and a fluorine atom. When [X] / [Metal] is greater than 0.1, X ⁻ → X ₂ is generated during the metal redox reaction, and X ₂ easily cross-oxidizes with the deposited metal to dissolve the deposited metal. Therefore, the molar concentration of halogen atoms is preferably as low as possible relative to the molar concentration of metallic silver. In the present invention, 0 ≦ [X] / [Metal] ≦ 0.001 is more preferable. In the case of adding halogen ions, the halogen species preferably have a total molar concentration of [I] <[Br] <[Cl] <[F] from the viewpoint of improving memory properties.

〔substrate〕
Examples of the substrate that can be used in the present invention include polyolefins such as polyethylene and polypropylene, polycarbonates, cellulose acetate, polyethylene terephthalate, polyethylene dinaphthalene dicarboxylate, polyethylene naphthalates, polyvinyl chloride, polyimide, and polyvinyl acetal. Synthetic plastic films such as polystyrene can also be preferably used. Syndiotactic polystyrenes are also preferred. These can be obtained, for example, by the methods described in JP-A Nos. 62-117708, 1-46912, and 1-178505. Further, a metal substrate such as stainless steel, a paper support such as baryta paper and resin coated paper, and a support provided with a reflective layer on the plastic film, supported by JP-A-62-253195 (pages 29-31) The thing described as a body is mentioned. RDNo. 17643, page 28, ibid. No. 18716, page 647, right column to page 648, left column, and No. 307105, page 879 can also be preferably used. As these supports, those having resistance to curling due to heat treatment of Tg or less as in US Pat. No. 4,141,735 can be used. Further, the surface of these supports may be subjected to surface treatment for the purpose of improving the adhesion between the support and other constituent layers. In the present invention, glow discharge treatment, ultraviolet irradiation treatment, corona treatment, and flame treatment can be used as the surface treatment. Furthermore, the support body described in pages 44 to 149 of publicly known technology No. 5 (issued by Aztec Co., Ltd. on March 22, 1991) can also be used. Furthermore, RDNo. 308119, page 1009, Product Licensing Index, Volume 92, P108, “Supports”, and the like. In addition, a glass substrate or an epoxy resin kneaded with glass can be used.

(Transparent conductive layer)
The display element of the present invention can have a transparent conductive layer. The transparent conductive layer 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. Another example is a method using a conductive polymer.

[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. Furthermore, Research Disclosure and those described in 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. Two or more of these binders can be used in combination.

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

  Polymers dispersed in an aqueous solvent include 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.

(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), an extraction method ( After forming a constituent layer with a solvent-soluble organic substance or inorganic substance and a binder that does not dissolve in the solvent, the organic substance or inorganic substance is dissolved with the solvent to obtain pores), and the polymer is heated or degassed Known forming methods such as a foaming method in which foaming is performed, a phase change method in which a mixture of polymers is phase-separated by operating a good solvent and a poor solvent, and a radiation irradiation method in which pores are formed by radiating various types of radiation Can be used. Specifically, JP-A-10-30181, JP-A-2003-107626, JP-B-7-95403, 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.

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

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

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

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

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

Additive RD17643 RD18716 RD308119
Page Classification Page Classification Page Classification Chemical sensitizer 23 III 648 Upper right 96 III
Sensitizing dye 23 IV 648-649 996-8 IV
Desensitizing dye 23 IV 998 IV
Dye 25-26 VIII 649-650 1003 VIII
Development accelerator 29 XXI 648 Upper right Anti-fogging agent / stabilizer
24 IV 649 Upper right 1006-7 VI
Brightener 24 V 998 V
Hardener 26 X 651 Left 1004-5 X
Surfactant 26-7 XI 650 Right 1005-6 XI
Antistatic agent 27 XII 650 Right 1006-7 XIII
Plasticizer 27 XII 650 Right 1006 XII
Slipper 27 XII
Matting agent 28 XVI 650 Right 1008-9 XVI
Binder 26 XXII 1003-4 IX
Support 28 XVII 1009 XVII
〔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. Above all, 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.

[Display element driving method]
The method for controlling the transparent state and the colored state of the display element of the present invention is preferably determined based on the redox potential of the electrochromic compound and the deposition overvoltage of the metal compound.

  For example, in the case of a display element having an electrochromic compound and a metal compound between counter electrodes, a colored state other than black is shown on the oxidation side and a black state is shown on the reduction side. As an example of the control method in this case, the electrochromic compound is oxidized by applying a voltage higher than the redox potential of the electrochromic compound to show a colored state other than black, and the redox potential of the electrochromic compound and the metal compound The electrochromic compound is reduced to return to the white state by applying a voltage between the deposition overvoltage of the metal, and the black state is exhibited by depositing the metal on the electrode by applying a voltage lower than the deposition overvoltage of the metal compound. There is a method of dissolving and decoloring the deposited metal by applying a voltage between the oxidation potential of the metal and the redox potential of the electrochromic compound.

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

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

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

Example 1
<< Production of display element >>
[Production of Display Element 1-1]
(Production of electrode 1)
An ITO (Indium Tin Oxide) film having a pitch of 145 μm and an electrode width of 130 μm is formed on a 2 cm × 4 cm glass substrate having a thickness of 1.5 mm according to a known method, and an ITO electrode (electrode 1) is produced. did.

(Preparation of electrode 2)
After applying a paste liquid containing titanium dioxide having an average particle diameter of 10 nm on the electrode 1 by a screen printing method, the paste liquid was heated at 150 ° C. for 30 minutes to remove the solvent of the paste liquid. A nanoporous membrane was formed. Next, the following ink liquid 1 was applied to the entire nanoporous film with an ink jet recording apparatus having a piezo recording head, to prepare an electrode 2.

<Preparation of ink liquid 1>
Bis- (2-phosphonoethyl) -4,4′-bipyridinium dibromide (described as compound EC-1 in Table 1) was dissolved in acetonitrile / ethanol = 1/1 to give 3 mmol / L, and the ink was dissolved. Liquid 1 was prepared.

(Preparation of electrode 3)
A nickel electrode having an electrode thickness of 0.1 μm, a pitch of 145 μm, and an electrode interval of 130 μm is formed on a glass substrate having a thickness of 1.5 mm and a size of 2 cm × 4 cm by using a known method. A gold-nickel electrode (electrode 3) having a depth of 0.05 μm replaced with gold from the electrode surface was prepared.

(Preparation of electrolyte 1)
0.025 g of tetrabutylammonium perchloride was dissolved in 2.5 g of dimethyl sulfoxide (abbreviated as DMSO in Table 1) to obtain an electrolytic solution 1.

(Production of display element)
After the periphery of the electrode 3 is edged with an olefin-based sealant containing glass spherical beads having an average particle diameter of 40 μm as a volume fraction of 10%, the striped electrodes are orthogonal to the electrodes 3 and 2 respectively. The cells were bonded together and further heated and pressed to produce an empty cell. The electrolytic solution 1 was vacuum-injected into the empty cell, and the injection port was sealed with an epoxy-based ultraviolet curable resin to produce a display element 1-1.

[Production of Display Element 1-2]
(Preparation of electrolyte 2)
In 2.5 g of dimethyl sulfoxide, 0.5 g of the following compound U and 0.025 g of tetrabutylammonium perchloride were dissolved to obtain an electrolytic solution 2.

(Production of display element)
In the production of the display element 1-1, a display element 1-2 was produced in the same manner except that the electrolytic solution 1 was changed to the electrolytic solution 2.

[Production of Display Element 1-3]
(Preparation of electrolyte 3)
In 2.5 g of dimethyl sulfoxide, 0.5 g of the following compound O and 0.025 g of tetrabutylammonium perchloride were dissolved to obtain an electrolytic solution 3.

(Production of display element)
In the production of the display element 1-1, a display element 1-3 was produced in the same manner except that the electrolytic solution 1 was changed to the electrolytic solution 3.

[Production of Display Element 1-4]
(Preparation of electrolyte 4)
0.5 g of Exemplified Compound SQ-5 and 0.025 g of tetrabutylammonium perchloride were dissolved in 2.5 g of dimethyl sulfoxide to obtain an electrolyte solution 4.

(Production of display element)
A display element 1-4 was manufactured in the same manner as in the manufacture of the display element 1-1 except that the electrolytic solution 1 was changed to the electrolytic solution 4.

[Production of Display Element 1-5]
(Preparation of electrode 4)
After applying a paste liquid containing titanium dioxide having an average particle diameter of 10 nm on the electrode 1 by a screen printing method, the paste liquid was heated at 150 ° C. for 30 minutes to remove the solvent of the paste liquid. A nanoporous membrane was formed. Next, the following ink liquid 2 was applied to the entire nanoporous film with an ink jet recording apparatus having a piezo recording head to produce an electrode 2.

<Preparation of ink liquid 2>
Ink Liquid 2 was prepared by dissolving Exemplified Compound A-42 in acetonitrile / ethanol = 1/1 so as to be 3 mmol / L.

(Preparation of electrolyte 5)
In 2.5 g of Exemplified Compound III-4, 0.5 g of Exemplified Compound SQ-5 and 0.025 g of spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate were dissolved to obtain an electrolytic solution 5. .

(Production of display element)
After the periphery of the electrode 3 is edged with an olefin-based sealant containing glass spherical beads having an average particle size of 40 μm as a volume fraction of 10%, the striped electrodes are orthogonal to the electrodes 3 and 4 respectively. The cells were bonded together and further heated and pressed to produce an empty cell. The electrolytic solution 1 was vacuum-injected into the empty cell, and the injection port was sealed with an epoxy-based ultraviolet curable resin to produce a display element 1-5.

[Production of Display Element 1-6]
(Preparation of electrolyte 6)
In 2.5 g of Exemplified Compound III-4, 0.5 g of Exemplified Compound SQ-1 and 0.025 g of spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate were dissolved to obtain an electrolytic solution 6. .

(Production of display element)
A display element 1-6 was produced in the same manner as in the production of the display element 1-5, except that the electrolytic solution 5 was changed to the electrolytic solution 6.

[Production of Display Element 1-7]
(Preparation of electrolyte solution 7)
In 2.5 g of Exemplified Compound III-4, 0.5 g of Exemplified Compound SQ-5, 0.5 g of Exemplified Compound 3-5, and 0.025 g of Spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate It melt | dissolved and the electrolyte solution 7 was obtained.

(Production of display element)
A display element 1-7 was produced in the same manner as in the production of the display element 1-5 except that the electrolytic solution 5 was changed to the electrolytic solution 7.

[Production of Display Element 1-8]
(Preparation of electrolyte 8)
In 2.5 g of Exemplified Compound III-4, 0.5 g of Exemplified Compound SQ-1, 0.5 g of Exemplified Compound 3-5 and 0.025 g of Spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate It melt | dissolved and the electrolyte solution 8 was obtained.

(Production of display element)
A display element 1-8 was produced in the same manner as in the production of the display element 1-5 except that the electrolytic solution 5 was changed to the electrolytic solution 8.

[Production of Display Element 1-9]
(Preparation of electrolyte 9)
In 2.5 g of Exemplified Compound III-4, 0.5 g of Exemplified Compound SQ-5, 0.5 g of Compound U, and 0.025 g of spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate were dissolved. Electrolyte 9 was obtained.

(Production of display element)
A display element 1-9 was produced in the same manner as in the production of the display element 1-5 except that the electrolytic solution 5 was changed to the electrolytic solution 9.

[Production of Display Element 1-10]
(Preparation of electrolyte 10)
In 2.5 g of Exemplified Compound III-4, 0.5 g of Exemplified Compound SQ-1, 0.5 g of Compound U, and 0.025 g of spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate were dissolved. The electrolytic solution 12 was obtained.

(Production of display element)
A display element 1-10 was produced in the same manner as in the production of the display element 1-5 except that the electrolytic solution 5 was changed to the electrolytic solution 10.

[Production of Display Element 1-11]
(Preparation of electrolyte solution 11)
In 2.5 g of dimethyl sulfoxide, 0.5 g of Exemplified Compound SQ-5 and 0.025 g of spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate were dissolved to obtain an electrolytic solution 11.

(Production of display element)
A display element 1-11 was produced in the same manner as in the production of the display element 1-5 except that the electrolytic solution 5 was changed to the electrolytic solution 11.

[Production of Display Element 1-12]
(Preparation of electrolyte solution 12)
In 2.5 g of Exemplified Compound III-4, 0.5 g of Exemplified Compound SQ-5, 0.1 g of Exemplified Compound C-14, and Spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate 0.025g was melt | dissolved and the electrolyte solution 12 was obtained.

(Production of display element)
A display element 1-12 was produced in the same manner as in the production of the display element 1-5 except that the electrolytic solution 5 was changed to the electrolytic solution 12.

[Production of Display Element 1-13]
(Preparation of electrode 5)
After applying a paste liquid containing titanium dioxide having an average particle diameter of 10 nm on the electrode 1 by a screen printing method, the paste liquid was heated at 150 ° C. for 30 minutes to remove the solvent of the paste liquid. A nanoporous membrane was formed. Next, the following ink liquid 3 was applied to the entire nanoporous film with an ink jet recording apparatus having a piezo recording head, to produce an electrode 5.

<Preparation of ink liquid 3>
Ink Liquid 3 was prepared by dissolving Exemplified Compound A-113 in acetonitrile / ethanol = 1/1 so as to be 3 mmol / L.

(Production of display element)
A display element 1-13 was produced in the same manner as in the production of the display element 1-12 except that the electrode 4 was changed to the electrode 5.

[Production of Display Element 1-14]
(Preparation of electrode 6)
After applying a paste liquid containing titanium dioxide having an average particle diameter of 10 nm on the electrode 1 by a screen printing method, the paste liquid was heated at 150 ° C. for 30 minutes to remove the solvent of the paste liquid. A nanoporous membrane was formed. Next, the following ink liquid 4 was applied to the entire nanoporous film with an ink jet recording apparatus having a piezo recording head, to produce an electrode 6.

<Preparation of ink liquid 4>
Ink Liquid 3 was prepared by dissolving Exemplified Compound A-115 in acetonitrile / ethanol = 1/1 so as to be 3 mmol / L.

(Production of display element)
A display element 1-14 was produced in the same manner as in the production of the display element 1-12 except that the electrode 4 was changed to the electrode 6.

<< Evaluation of display element >>
(Evaluation of light resistance)
Measuring the reflectance from the display electrode side by the spectral colorimeter CM-3700d manufactured by Konica Minolta Sensing Inc. In the undriven state, the resulting reflectance was white reflectance R _W (0hr).

Next, a voltage of -1.5 V is applied to the transparent elements on the display elements 1-1 to 1-4, a voltage of +1.5 V is applied on the display elements 1-5 to 1-14, and an application time is applied. , The reflectance R _C (0) and the application time t in a colored state such that the contrast CR (0 hr) defined by the following formula is 10 were obtained.

CR (0 hr) = R _W (0 hr) / R _C (0 hr)
Next, each display element is returned to a white display state, irradiated with 70,000 lux xenon light from the transparent electrode side for 5 hours, and a contrast CR (5 hr) defined by the following formula is obtained. It was.

CR (5 hr) = R _W (5 hr) / R _C (5 hr)
In the formula, R _W (5 hr): reflectivity when displaying white R _C (5 hr) represents the reflectivity when colored and displayed at an application time t determined before irradiating xenon light, and reflectivity The value of is a reflectance value at a wavelength that takes a minimum value in the visible light region in the colored state.

  Here, the higher the contrast CR (5 hr) after irradiation with xenon light, the better the light resistance.

  Table 1 shows the evaluation results of the respective display elements obtained as described above.

  As is clear from the results shown in Table 1, it can be seen that the display element satisfying the configuration of the present invention is superior in light resistance to the comparative example.

Example 2
<< Production of display element >>
[Production of Display Element 2-1]
(Preparation of electrolytic solution 13)
In 2.5 g of dimethyl sulfoxide, 0.1 g of bismuth chloride, 0.2 g of lithium bromide and 0.025 g of tetrabutylammonium perchloride were dissolved to obtain an electrolytic solution 13.

(Production of display element)
The periphery of the electrode 3 described in Example 1 is trimmed with an olefin-based sealant containing 10% glass spherical beads having an average particle diameter of 40 μm as a volume fraction, and then the electrode 3 and the electrode described in Example 1 are used. 4 were bonded so that the striped electrodes were orthogonal to each other, and further heated and pressed to produce an empty cell. The electrolytic solution 13 was vacuum-injected into the empty cell, and the injection port was sealed with an epoxy-based ultraviolet curable resin to produce a display element 2-1.

[Production of Display Element 2-2]
(Preparation of electrolytic solution 14)
In 2.5 g of dimethyl sulfoxide, 0.1 g of bismuth chloride, 0.5 g of compound AO-1, 0.2 g of lithium bromide and 0.025 g of tetrabutylammonium perchloride were dissolved to obtain an electrolytic solution 14. .

(Production of display element)
A display element 2-2 was produced in the same manner as in the production of the display element 2-1, except that the electrolytic solution 13 was changed to the electrolytic solution 14.

[Production of Display Element 2-3]
(Preparation of electrolytic solution 15)
In 2.5 g of dimethyl sulfoxide, 0.1 g of bismuth chloride, 0.5 g of exemplary compound SQ-5, 0.2 g of lithium bromide, and 0.025 g of tetrabutylammonium perchloride were dissolved to obtain an electrolytic solution 15. .

(Production of display element)
A display element 2-3 was produced in the same manner as in the production of the display element 2-1, except that the electrolytic solution 13 was changed to the electrolytic solution 15.

[Production of Display Element 2-4]
(Preparation of electrolytic solution 16)
In 2.5 g of Exemplified Compound III-4, 0.1 g of silver p-toluenesulfonate, 0.2 g of Exemplified Compound II-12, 0.5 g of Exemplified Compound SQ-5, and tetrafluoroborate spiro- (1 , 1 ′)-bipyrrolidinium 0.025 g was dissolved to obtain an electrolytic solution 16.

(Production of display element)
A display element 2-4 was produced in the same manner as in the production of the display element 2-1, except that the electrolytic solution 13 was changed to the electrolytic solution 16.

[Production of Display Element 2-5]
(Preparation of electrolytic solution 17)
In 2.5 g of Exemplified Compound III-4, 0.1 g of silver p-toluenesulfonate, 0.2 g of Exemplified Compound II-12, 0.5 g of Exemplified Compound SQ-1 and tetrafluoroborate spiro- (1 , 1 ′)-bipyrrolidinium 0.025 g was dissolved to obtain an electrolytic solution 17.

(Production of display element)
A display element 2-5 was produced in the same manner as in the production of the display element 2-1, except that the electrolytic solution 13 was changed to the electrolytic solution 17.

[Production of Display Element 2-6]
(Preparation of electrolytic solution 18)
In 2.5 g of the exemplified compound III-4, 0.1 g of silver p-toluenesulfonate, 0.2 g of the exemplified compound II-12, 0.5 g of the exemplified compound SQ-5 and 0. 5 g and 0.025 g of spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate were dissolved to obtain an electrolytic solution 18.

(Production of display element)
A display element 2-6 was produced in the same manner as in the production of the display element 2-1, except that the electrolytic solution 13 was changed to the electrolytic solution 18.

[Production of Display Element 2-7]
(Preparation of Electrolytic Solution 19)
In 2.5 g of the exemplified compound III-4, 0.1 g of silver p-toluenesulfonate, 0.2 g of the exemplified compound II-12, 0.5 g of the exemplified compound SQ-1, and 0. 5 g and 0.025 g of spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate were dissolved to obtain an electrolytic solution 19.

(Production of display element)
A display element 2-7 was produced in the same manner as in the production of the display element 2-1, except that the electrolytic solution 13 was changed to the electrolytic solution 19.

[Production of Display Element 2-8]
(Preparation of electrolytic solution 20)
In 2.5 g of Example Compound III-4, 0.1 g of silver p-toluenesulfonate, 0.2 g of Example Compound II-12, 0.5 g of Example Compound SQ-5, and 0.5 g of UV-1 An electrolytic solution 20 was obtained by dissolving 0.025 g of spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate.

(Production of display element)
A display element 2-8 was produced in the same manner as in the production of the display element 2-1, except that the electrolytic solution 13 was changed to the electrolytic solution 20.

[Production of Display Element 2-9]
(Preparation of electrolyte solution 21)
In 2.5 g of Example Compound III-4, 0.1 g of silver p-toluenesulfonate, 0.2 g of Example Compound II-12, 0.5 g of Example Compound SQ-1, and 0.5 g of UV-1 An electrolytic solution 21 was obtained by dissolving 0.025 g of spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate.

(Production of display element)
A display element 2-9 was produced in the same manner as in the production of the display element 2-1, except that the electrolytic solution 13 was changed to the electrolytic solution 21.

[Production of Display Element 2-10]
(Preparation of electrolytic solution 22)
In 2.5 g of Exemplified Compound III-4, 0.1 g of silver p-toluenesulfonate, 0.2 g of Compound I-3, 0.5 g of Exemplified Compound SQ-5, and tetrafluoroborate spiro- (1, 1 ')-bipyrrolidinium 0.025g was melt | dissolved and the electrolyte solution 22 was obtained.

(Production of display element)
A display element 2-10 was produced in the same manner as in the production of the display element 2-1, except that the electrolytic solution 13 was changed to the electrolytic solution 22.

[Production of Display Element 2-11]
(Preparation of electrolyte solution 23)
In 2.5 g of dimethyl sulfoxide, 0.1 g of silver p-toluenesulfonate, 0.2 g of Exemplified Compound II-12, 0.5 g of Exemplified Compound SQ-5, and tetrafluoroborate spiro- (1,1 ′) -Electrolyte solution 23 was obtained by dissolving 0.025 g of bipyrrolidinium.

(Production of display element)
A display element 2-11 was produced in the same manner as in the production of the display element 2-1, except that the electrolytic solution 13 was changed to the electrolytic solution 23.

[Production of Display Element 2-12]
(Preparation of electrolyte solution 24)
In 2.5 g of Exemplified Compound III-4, 0.1 g of Silver p-Toluenesulfonate, 0.2 g of Exemplified Compound II-12, 0.5 g of Exemplified Compound SQ-5, and Exemplified Compound C-14 were reduced to 0.0. 1 g and 0.025 g of spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate were dissolved to obtain an electrolytic solution 24.

(Production of display element)
A display element 2-12 was produced in the same manner as in the production of the display element 2-1, except that the electrolytic solution 13 was changed to the electrolytic solution 24.

[Production of Display Element 2-13]
(Production of display element)
A display element 2-13 was produced in the same manner as the display element 2-12 except that the electrode 4 was changed to the electrode 5 described in Example 1.

[Production of Display Element 2-14]
(Production of display element)
A display element 2-14 was produced in the same manner as the display element 2-12 except that the electrode 4 was changed to the electrode 6 described in Example 1.

<< Evaluation of display element >>
Light resistance was evaluated by the method described in Example 1, and the evaluation results of the obtained display elements are shown in Table 2.

  As is clear from the results shown in Table 2, it can be seen that the display element satisfying the configuration of the present invention is superior in light resistance to the comparative example.

Claims (15)

A display element comprising an electrolyte, an electrochromic compound, and a compound having a singlet oxygen quenching rate (kq) of 10 ⁵ or more and 10 ¹⁰ or less between opposing electrodes. 2. The compound according to claim 1, wherein the compound having a singlet oxygen quenching rate (kq) of 10 ⁵ or more and 10 ¹⁰ or less is a compound represented by the following general formula [1] or [2]. The display element as described in.

[Wherein, R ₁ represents an aryl group or a heterocyclic group, and Z ₁ and Z ₂ each represent an alkylene group having 1 to 3 carbon atoms. However, the sum total of carbon number of the alkylene group represented by Z < ₁ > and Z < ₂ > is 3-6. A represents an oxygen atom, NZ ₃ , S (O) _n , and Z ₃ represents an alkyl group or an aryl group. n represents an integer of 0 to 2. ]

[Wherein R ₂ represents an alkyl group or a trialkylsilyl group, and R ₃ , R ₄ , R ₅ , R ₆ and R ₇ are each a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, An alkenyl group, an alkenyloxy group, an acylamino group, a halogen atom, an alkylthio group, an arylthio group, an alkoxycarbonyl group, an acyloxy group, an acyl group, or a sulfonamide group is represented. Two groups out of R _{2 to} R ₇ may be linked to form a 5- to 6-membered ring. ] The display element according to claim 1 or 2, wherein a compound represented by the following general formula [3] is contained between the counter electrodes.

[Wherein R ₈ , R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are each a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an alkenyl group, an alkenyloxy group, an acylamino group, a halogen atom, An alkylthio group, an arylthio group, an alkoxycarbonyl group, an acyloxy group, an acyl group, or a sulfonamide group is represented. Two groups may form a 5- or 6-membered ring by combining one of R ₈ to R _12. However, neither R ₈ nor R ₁₂ is an alkyl group. ] The display element according to any one of claims 1 to 3, wherein the electrochromic compound is a compound represented by the following general formula (A).

[Wherein, R ¹ represents a substituted or unsubstituted aryl group, and R ² and R ³ each represent a hydrogen atom or a substituent. X represents> N—R ⁴ , an oxygen atom or a sulfur atom, and R ⁴ represents a hydrogen atom or a substituent. ] 5. The display element according to claim 1, wherein a singlet oxygen quenching rate (kq) of the compound is 10 ⁶ or more and 10 ⁸ or less.   The display element according to any one of claims 1 to 5, wherein at least one of the counter electrodes has a porous layer containing a metal oxide.   The display element according to claim 6, wherein the metal oxide is at least one selected from titanium dioxide, zinc oxide, and tin oxide.   The display element according to claim 6 or 7, wherein the electrochromic compound is fixed to the porous layer containing the metal oxide.   The display according to any one of claims 6 to 8, wherein the compound represented by the general formula (A) has a group that adsorbs to the metal oxide. element. The group adsorbing to the metal oxide is —COOH, —P═O (OH) ₂ , —OP═O (OH) ₂ or —Si (OR) ₃ (R represents an alkyl group). The display element according to claim 9, wherein:   11. The display element according to claim 1, wherein an N-oxyl derivative is held between the counter electrodes.   The display element according to any one of claims 1 to 11, wherein the electrolyte contains a metal salt compound.   The display element according to claim 12, wherein the metal salt compound is a silver salt compound. The said electrolyte contains at least 1 sort (s) chosen from the compound represented by the following general formula (I) and (II), The any one of Claims 1-13 characterized by the above-mentioned. Display element.
Formula (I)
R ⁵ -S-R ⁶
[Wherein, R ⁵ and R ⁶ each represents a substituted or unsubstituted hydrocarbon group. However, when a ring containing an S atom is formed, an aromatic group is not taken. ]

[Wherein, M represents a hydrogen atom, a metal atom or quaternary ammonium. Z represents a nitrogen-containing heterocyclic ring. n represents an integer of 0 to 5, and R ⁷ represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkylcarbonamide group, an arylcarbonamide group, an alkylsulfonamide group, an arylsulfonamide group, an alkoxy group, an aryloxy group Group, alkylthio group, arylthio group, alkylcarbamoyl group, arylcarbamoyl group, carbamoyl group, alkylsulfamoyl group, arylsulfamoyl group, sulfamoyl group, cyano group, alkylsulfonyl group, arylsulfonyl group, alkoxycarbonyl group, aryl Represents an oxycarbonyl group, an alkylcarbonyl group, an arylcarbonyl group, an acyloxy group, a carboxyl group, a carbonyl group, a sulfonyl group, an amino group, a hydroxy group or a heterocyclic group, and when n is 2 or more, each R ⁷ is They may be the same or different, and may be linked together to form a condensed ring. ] 14. The electrolyte according to any one of claims 1 to 13, wherein the electrolyte contains at least one selected from compounds represented by the following general formulas (III) and (IV). Display element.

[Wherein, L represents an oxygen atom or CH ₂ , and R ^{8 to} R ¹¹ each represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group, or an alkoxy group. ]

[Wherein, R ¹² and R ¹³ each represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group or an alkoxy group. ]