JP2009288409A - Display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new display element which performs bright white display, high contrast black-and-white display, and full color display by a simple member configuration. <P>SOLUTION: The display element has an electrochromic compound, a metal salt compound, an electrolyte, and a white scattering material between electrodes facing each other and performs black display, white display, and multi-color display of three or more colors of color display other than black by driving operation of the electrodes facing each other. The electrochromic compound is represented by general formula (1). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a display element.

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

  As such electronic information browsing means, conventional liquid crystal displays and CRTs, and in recent years, light-emitting types such as organic EL displays are mainly used. Particularly, when electronic information is document information, it is relatively long time. It is necessary to keep an eye on the light-emitting display over time, and these actions are not necessarily human-friendly, and generally the disadvantages of the light-emitting display are flickering eyes, inconvenient to carry, limited reading posture, It is known that it is necessary to adjust the line of sight to a still screen, and that power consumption increases when read for a long time.

  As a display means to compensate for these drawbacks, a reflective display that uses external light and does not consume power for image retention (memory type) is known, but it still has sufficient performance. It ’s hard. For example, a 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 it is difficult to say that many of the manufacturing methods used to manufacture the constituent members are simple. In addition, since the polymer dispersed liquid crystal requires a high voltage and utilizes the difference in refractive index between organic substances, the contrast of the obtained image is not sufficient. In addition, the polymer network type liquid crystal has a high voltage, and a complicated TFT circuit is required to improve the memory performance. In addition, a display element based on electrophoresis requires a high voltage of 10 V or more, and there is a concern about durability due to aggregation of electrophoretic particles. In the past, it has not been known what has sufficient performance.

  The electrochromic method is known as a method capable of full-color display, and can be driven at a low voltage of 3 V or less. However, bright white, sufficient black-and-white contrast, and when trying to display a color, different colors are displayed. It is necessary to laminate three layers, and there is a concern about high cost due to a complicated element configuration. Further, a full-color electrochromic element (for example, refer to Patent Document 1) using flat ground mixing is known. However, in this method, dark black cannot be obtained because of flat ground mixing, and black and white contrast is not sufficient. In addition, it is known to use a polypyridine-based compound for an electrochromic device (see, for example, Patent Document 2), but with this configuration, only two colors can be displayed as display colors, and in particular, black display cannot be obtained.

As a method capable of displaying black, an electrodeposition method (hereinafter, abbreviated as ED method) using dissolution precipitation of metal or metal salt is known (for example, see Patent Document 3). The ED method is an advantageous method for obtaining sufficient black-and-white contrast, but it is necessary to use B, G, R or Y, M, C color filters to display full color. There was a problem that black and white contrast could not be fully utilized.
JP 2003-270670 A Japanese Patent No. 2930860 JP 2003-241227 A

  The present invention has been made in view of the above problems, and an object thereof is to provide a novel display element capable of realizing bright white display, high-contrast monochrome display and full-color display with a simple member configuration. It is in.

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

  1. An electrochromic compound, a metal salt compound, an electrolyte, and a white scatterer are contained between the counter electrodes, and the multi-color display of three or more colors of black display, white display, and color display other than black is performed by driving the counter electrode. In the display element, the electrochromic compound is represented by the following general formula (1) or (2).

(In the formula, R _{1 to} R ₆ represent a hydrogen atom or a substituent, but at least one of R _{1 to} R ₆ represents a substituent, R ₁ and R ₂ , R ₃ and R ₄ , R ₅ and R ₆ is not bonded to each other to form a ring, X ₁ and X ₂ represent —NR ₉ —, —O—, or —S—, n represents an integer of 1 to 3, and R ₉ represents a hydrogen atom. Or represents a substituent.)

(Wherein R ₇ and R ₈ represent a hydrogen atom or a substituent, and R ₇ and R ₈ may be linked together to form a 5- to 6-membered ring. X ₁ and X ₂ are —NR ₉ represents -O- or -S-, m represents an integer of 0 to 3, R ₉ represents a hydrogen atom or a substituent, and A and B are necessary for forming a 5- to 6-membered ring. Represents an atomic group.)
2. _2. The display element according to 1 above, wherein in the general formula (1), X ₁ and X ₂ are both NH.

  3. 3. The display element according to 1 or 2 above, wherein the metal salt compound is a silver salt compound.

  4). 4. The display element according to any one of items 1 to 3, wherein the electrochromic compound is supported on at least one surface of the counter electrode.

5. The electrochromic compound is selected from CO ₂ H, —PO (OH) ₂ , —OPO (OH) ₂ , —SO ₃ H, and —Si (OR) ₃ (R represents a hydrogen atom or an alkyl group). 5. The display element according to any one of 1 to 4, which has at least one substituent.

  6). 6. The display element according to any one of 1 to 5, wherein at least one of the counter electrodes is composed of a metal oxide porous layer, and an electrochromic compound is supported on the metal oxide porous layer.

7). The white scattering material _is, the display device according to the sixth any one which comprises a TiO 2, ZnO or _Al 2 _{O 3.}

  8). 8. The display element according to any one of 1 to 7, wherein a black state is displayed by a cathode reaction.

  9. 9. The display element as described in any one of 1 to 8 above, wherein the colored display other than black is a color display by planarly arranging display regions having different hues.

  According to the present invention, a novel display element capable of realizing bright white display, stable high-contrast monochrome display and full-color display with a simple member configuration can be provided.

  Details of the present invention will be described below.

<< Basic configuration of display element >>
The constituent layers between the counter electrodes in the display element of the present invention will be described.

  The display element of the present invention is characterized by performing multicolor display of three or more colors of black display, white display, and color display other than black by driving the counter electrode.

  In the display element of the present invention, the display portion is provided with one corresponding counter electrode. The electrode 1 which is one of the counter electrodes close to the display unit is provided with a transparent electrode such as an ITO electrode, and the other electrode 2 is provided with a conductive electrode. Between the electrode 1 and the electrode 2, an electrochromic compound, a metal salt compound, an electrolyte and a white scattering material according to the present invention are contained. By applying a voltage of both positive and negative polarities between the counter electrodes, the white scatterer disposed between the electrodes and the difference in the coloring state of each oxidation / reduction state of the electrochromic compound and the metal salt compound are utilized. And various coloring states can be switched reversibly.

  In addition, it is preferable to perform color display and black and white display by arranging display areas with different hues in a colored display other than black, and the method of arranging display areas with different hues in a plane is different types. It is preferable to support the electrochromic compound on the metal oxide porous layer.

  When full-color display is performed in the display element of the present invention, a pair of counter electrodes are separated by partition walls, and electrolytic solutions having different colors (electrolyte solutions containing different types of electrochromic compounds) are sealed in each partition wall. Examples thereof include a method of performing planar arrangement and a method of separately coating and supporting different electrochromic compounds on the metal oxide porous layer without using partition walls. Examples of the coating method include a printing method and an inkjet method.

  In order to promote the electrochemical reaction of the electrochromic compound, an auxiliary compound (promoter) that can be oxidized and reduced may be added.

(promoter)
There is no restriction | limiting in particular as a promoter, According to the objective, it can select suitably. In particular, when used as a counter electrode reactant, a known electrochromic compound (hereinafter also referred to as EC compound) can be used. In addition, when used as a redox mediator, according to the properties of EC compounds used as display dyes, Journal of Synthetic Organic Chemistry, Vol. 43, No. 6 (Special Issue on Organic Synthesis Using Electric Energy) (1985) etc. The known mediators described can be appropriately selected and used.

Examples of preferred promoters that can be used in the present invention include the following compounds.
1) N-oxyl derivatives typified by TEMPO, N-hydroxyphthalimide derivatives, hydroxamic acid derivatives, etc., compounds having an N—O bond 2) Allyloxy free radicals introduced with a bulky substituent at the 0-position, such as galvinoxyl 3) Ferrocene etc., metallocene derivatives 4) benzyl (diphenylethanedione) derivatives 5) tetrazolium salts / formazan derivatives 6) azine compounds such as phenazine, phenothiazine, phenoxazine, acridine 7) pyridinium compounds such as viologen and others, benzoquinone Derivatives, hydrazyl free radical compounds such as verdazil, thiazyl free radical compounds, hydrazone derivatives, phenylenediamine derivatives, triallylamine derivatives, tetrathiafulvalene derivatives, tetracyanoquinodimethane derivatives, thianthrene derivatives Conductors can be used as promoters.

  In the display element of the present invention, promoters in the categories 1) to 7) are preferable, and 1) is particularly preferable.

"electrode"
(Display electrode)
In the display element of the present invention, it is preferable to use a transparent electrode on the display portion side among the counter electrodes. 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.

(Metal oxide porous layer)
A metal oxide porous layer is preferably formed on the transparent electrode on the display unit side in order to immobilize an EC compound or the like. In order to increase the surface area, the metal oxide porous layer has micropores capable of supporting an EC compound or the like on the surface and inside thereof. 1-5000 m < ² > / g is preferable and, as for the specific surface area of the said metal oxide porous layer, 10-2500 m < ² > / g is more preferable. Here, the specific surface area means the BET specific surface area obtained from the adsorption amount of nitrogen gas. If the specific surface area is too small, the amount of adsorption of the EC compound cannot be increased, and the object of the present invention may not be achieved.

  The metal oxide porous layer can be formed, for example, by binding or contacting a plurality of metal oxide semiconductor fine particles.

  The semiconductor fine particles contained in the metal oxide porous layer are not particularly limited and may be appropriately selected according to the purpose. For example, a single semiconductor, an oxide semiconductor, a compound semiconductor, an organic semiconductor, a composite oxide A semiconductor or a mixture thereof may be used, and these may contain impurities as a dopant. There is no particular limitation on the form of the semiconductor, and it may be single crystal, polycrystalline, amorphous, or a mixed form thereof.

As the semiconductor fine particles, metal oxide semiconductor fine particles are preferable. Metal oxide semiconductor is one having the property of a semiconductor metal oxide, for _{example, TiO 2, SnO 2, Fe} 2 O 3, SrTiO 3, WO 3, ZnO, ZrO 2, Ta 2 O 5, Nb 2 Examples include O ₅ , V ₂ O ₅ , In ₂ O ₃ , CdO, MnO, CoO, TiSrO ₃ , KTiO ₃ , Cu ₂ O, sodium titanate, barium titanate, and potassium niobate.

  The shape of the semiconductor fine particles is not particularly limited and can be appropriately selected according to the purpose. The shape may be any of a spherical shape, a nanotube shape, a rod shape, and a whisker shape, and two or more types having different shapes may be used. Fine particles can also be mixed. In the case of the spherical particles, the average particle size is preferably 0.1 to 1000 nm, and more preferably 1 to 100 nm. Two or more kinds of fine particles having different particle size distributions may be mixed. In the case of the rod-like particles, the aspect ratio is preferably 2 to 50000, and more preferably 5 to 25000.

  An electrode in which the EC compound represented by the general formula (1) of the present invention is supported on the electrode by chemical adsorption, physical adsorption, or the like can also be preferably used. It can be used as a full color display material that is reversible and has a memory property. As an example of use, for example, as shown in FIG. 1, in a display element provided with a display electrode, a display layer, an electrolyte, a white reflective layer, and a counter electrode, the EC compound of the present invention is used as the display layer, such as titanium oxide. By using a layer reacted with a porous metal oxide and applying a voltage of both positive and negative polarities between the counter electrodes, the EC compound is oxidized and reduced, and the difference in the colored state of each oxidation-reduction state Colored display and white display can be performed using a white scattering layer disposed between the electrodes.

(Counter electrode)
In the display element of the present invention, examples of the electrode that is not on the display unit side include a metal electrode and a carbon electrode, but a metal electrode is preferable. As the metal electrode, for example, known metal species such as platinum, gold, silver, copper, aluminum, zinc, nickel, titanium, bismuth, and alloys thereof can be used. The metal electrode is preferably a metal having a work function close to the redox potential of silver in the electrolyte. Among them, silver or a silver electrode having a silver content of 80% or more is advantageous for maintaining the reduced state of silver. Excellent in preventing dirt. As an electrode manufacturing method, an existing method such as an evaporation method, a printing method, an ink jet method, a spin coating method, or a CVD method can be used.

《Electrochromic compound (EC compound)》
The EC compound according to the present invention will be described.

  The EC compound used in the display element of the present invention is a compound having an electrochromic phenomenon, and the electrochromic phenomenon is a visible region by controlling the oxidation-reduction reaction of a substance electrically or electrochemically. This is a phenomenon that changes the color of a substance by changing the electron transition energy in the. Hereinafter, the EC compound represented by the general formula (1) or (2) according to the present invention will be described.

(Compound represented by the general formula (1))
The EC compound according to the present invention (hereinafter also referred to as the EC compound of the present invention) is represented by the general formula (1). In the general formula (1), R _{1 to} R ₆ represent a hydrogen atom or a substituent.

Substituents include halogen atoms (eg, fluorine, chlorine, bromine, iodine, etc.), alkyl groups (eg, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group) , Dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, chloromethyl group, trifluoromethyl group, trichloromethyl group, tribromomethyl group, pentafluoroethyl group, methoxyethyl group, etc.), cycloalkyl group (for example, cyclopentyl group) Cyclohexyl group etc.), alkenyl group (eg vinyl group, allyl group etc.), alkynyl group (eg ethynyl group, propargyl group etc.), aryl group (eg phenyl group, naphthyl group, p-nitrophenyl group, p -Fluorophenyl group, p-methoxyphenyl group, etc.), heterocyclic ring (For example, furyl group, thienyl group, pyridyl group, pyridazyl group, pyrimidyl group, pyrazyl group, triazyl group, imidazolyl group, pyrazolyl group, thiazolyl group, benzoimidazolyl group, benzoxazolyl group, quinazolyl group, phthalazyl group, pyrrolidyl group , Imidazolidyl group, morpholyl group, oxazolidyl group, etc.), hydroxyl group, alkoxy group (for example, methoxy group, ethoxy group, propoxy group, isopropyloxy phase, butoxy group, tert-butoxy group, sec-butoxy group, etc.) alkoxycarbonyl group (For example, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (for example, phenyloxycarbonyl group) Group, naphthyloxycarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylamino) Sulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2 -Ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), carbamoyl group (for example, Minocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group , Naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthyl) Sulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfuryl group) Nyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group (phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), cyano group, amino group (for example, Amino group, methylamino group, dimethylamino group, ethylamino group, diethylamino group, butylamino group, dibutylamino group, etc.), acylamino group (for example, acetamide group, propioamide group, isopropioamide group, butanamide group, pivaloylamide group) R _{1 to} R ₄ are preferably a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group, or an amino group, and more preferably a hydrogen atom, an aryl group, or an amino group. is there. The aryl group is preferably a phenyl group, and the amino group is preferably a phenylamino group. These phenyl group and phenylamino group may further have a substituent.

R _{5 to} R ₆ are preferably a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an acyloxy group, an alkoxy group, or a cyano group, and more preferably a hydrogen atom or an alkyl group. As the alkyl group, a methyl group, an ethyl group, and a butyl group are preferable.

At least one of R _{1 to} R ₆ represents a substituent. By introducing the substituent, the solubility of the EC compound of the present invention is improved, and the EC of the present invention depends on the type of the substituent to be introduced. It is possible to impart and control various physical properties such as a wavelength at the time of coloring the compound, a redox potential, and an adsorptivity.

In the present invention, from the viewpoints of the solubility of the compound represented by the general formula (1), the color tone in the visible region during coloring, and the stability, R ₁ and R ₂ , R ₃ and R ₄ , R ₅ and R ₆ is not bonded to each other to form a ring.

In the general formula _{(1), X 1, X} 2 are each _-NR 9 -, - represents a O- or -S-, preferably -NR ₉ - a.

R ₉ represents a hydrogen atom or a substituent, and R ₉ is preferably a hydrogen atom. Examples of the substituent include the same substituents represented by R _{1 to} R ₆ , but preferably 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, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, chloromethyl group, trifluoromethyl group, trichloromethyl group, tribromomethyl group, pentafluoroethyl group, methoxyethyl group, etc.) Aryl groups (eg, phenyl, naphthyl, p-nitrophenyl, p-fluorophenyl, p-methoxyphenyl, etc.), heterocyclic groups (eg, furyl, thienyl, pyridyl, pyridazyl, pyrimidyl) Group, pyrazyl group, triazyl group, imidazolyl group, pyrazolyl group, thiazolyl group, benzoy Dazolyl group, benzoxazolyl group, quinazolyl group, phthalazyl group, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexyl) A carbonyl group, an octylcarbonyl group, a 2-ethylhexylcarbonyl group, a dodecylcarbonyl group, a phenylcarbonyl group, a naphthylcarbonyl group, a pyridylcarbonyl group, and the like, more preferably an alkyl group and an aryl group. The alkyl group is preferably a butyl group, a pentyl group, a hexyl group, or an octyl group. The aryl group is preferably a phenyl group.

X ₁ and X ₂ may be the same or different, but are preferably the same.

  In the general formula (1), n represents an integer of 1 to 3, but the EC compound of the present invention is preferably an integer of 1 to 2 and more preferably 1 in order to have good absorption in the visible region when colored. It is.

(Compound represented by the general formula (2))
In the general formula (2), R ₇ and R ₈ represent a hydrogen atom or a substituent, but are preferably a hydrogen atom. Examples of the substituent include those similar to the substituents represented by R _{1 to} R ₆ in the general formula (1), preferably a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an acyloxy group, An alkoxy group and a cyano group are preferable, and a hydrogen atom and an alkyl group are more preferable. As the alkyl group, a methyl group, an ethyl group, and a butyl group are preferable.

R ₇ and R ₈ may be connected to each other to form a 5- to 6-membered ring. Examples of the 5- to 6-membered ring include a cyclopentane ring, a cyclohexane ring, a benzene ring, a pyridine ring, a thiophene ring, A furan ring, a pyran ring, a pyrrole ring, an imidazole ring, a pyrazole ring, a pyrazine ring, a pyrimidine ring, a thiazole ring, an oxazole ring, and the like are preferable, and a cyclohexane ring, a benzene ring, a pyridine ring, a thiophene ring, and more A benzene ring and a thiophene ring are preferable.

In the general formula _(2), X 1, _{X 2,} similarly to the _X 1, _{X 2} in the general formula _{(1), -NR 9 -,} - represents a O- or -S-, preferably -NR ₉ -.

R ₉ represents a hydrogen atom or a substituent, and R ₉ is preferably a hydrogen atom. Examples of the substituent include the same substituents represented by R _{1 to} R ₆ , but preferably an alkyl group (for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a tert-butyl group, a pentyl group). Group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, chloromethyl group, trifluoromethyl group, trichloromethyl group, tribromomethyl group, pentafluoroethyl group, methoxyethyl group, etc.), aryl Groups (eg, phenyl, naphthyl, p-nitrophenyl, p-fluorophenyl, p-methoxyphenyl, etc.), heterocyclic groups (eg, furyl, thienyl, pyridyl, pyridazyl, pyrimidyl) , Pyrazyl group, triazyl group, imidazolyl group, pyrazolyl group, thiazolyl group, benzimid Zolyl group, benzoxazolyl group, quinazolyl group, phthalazyl group, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexyl) A carbonyl group, an octylcarbonyl group, a 2-ethylhexylcarbonyl group, a dodecylcarbonyl group, a phenylcarbonyl group, a naphthylcarbonyl group, a pyridylcarbonyl group, and the like, more preferably an alkyl group and an aryl group. The alkyl group is preferably a butyl group, a pentyl group, a hexyl group, or an octyl group. The aryl group is preferably a phenyl group.

X ₁ and X ₂ may be the same or different, but are preferably the same.

  In the general formula (2), m represents an integer of 0 to 3, but is preferably an integer of 0 to 2 and more preferably 0 in order that the EC compound of the present invention has good absorption in the visible region when colored. ~ 1.

In the general formula (2), A and B represent an atomic group necessary for forming a 5- to 6-membered ring. Examples of the 5- to 6-membered ring include a benzene ring, a pyridine ring, a thiophene ring, and a furan. Ring, pyran ring, pyrrole ring, imidazole ring, pyrazole ring, pyrazine ring, pyrimidine ring, thiazole ring, oxazole ring, and the like are preferable, and a benzene ring, a pyridine ring, and a thiophene ring are preferable, and a benzene ring is more preferable. It is a ring. These 5- to 6-membered rings may further have a substituent, and examples of the substituent include the same substituents represented by R _{1 to} R ₆ , preferably an alkyl group. , An alkynyl group, an alkenyl group and a carboxyl group, more preferably an alkyl group and a carboxyl group.

  The compound represented by the general formula (1) or (2) of the present invention can be electrically oxidized / reduced, and either the oxidized form or the reduced form is represented by the general formula (1). Or what is necessary is just to have the structure represented by (2), Preferably it is a case where the structure of a reduced form is represented by General formula (1) or (2).

(Supported)
In the present invention, the EC compound is preferably supported on at least one surface of the counter electrode. In the present invention, the term “supported” refers to a state of being immobilized by chemical adsorption, physical adsorption or the like, and chemical adsorption is a phenomenon of covalent bonding, coordination bonding, ionic bonding among solid surface adsorption phenomena. , Which is a chemical bond force such as a metal bond or a hydrogen bond, and the heat of adsorption is usually about 20 to 100 kcal / mol. On the other hand, physical adsorption refers to a phenomenon in which the cause of the adsorption phenomenon is concentrated on the solid surface by van der Waals force, and the heat of adsorption is 10 kcal / mol or less.

Preferably, the EC compound is —CO ₂ H, —PO (OH) ₂ , —OPO (OH) ₂ , —SO ₃ H, —Si (OR) ₃ (R represents a hydrogen atom or an alkyl group). It is preferably supported on at least one surface of the counter electrode by at least one substituent selected from: and more preferably by —Si (OR) ₃ (R represents a hydrogen atom or an alkyl group). This is the case when it is supported on the surface of the electrode.

It is supported on the surface of the electrode by a substituent represented by —Si (OR) ₃ (R represents a hydrogen atom, an alkyl group). For example, —Si (OR) ₃ (R is a hydrogen atom) Represents an alkyl group.) As it is or after hydrolysis, a method of bonding to the metal oxide porous layer on the electrode or on the electrode through a silanol bond is preferable. It is the method of making it bond to a metal oxide porous layer via.

  Specific examples of the EC compounds represented by the general formulas (1) and (2) are shown below, but the present invention is not limited to these exemplified compounds.

  Although the synthesis example of exemplary compound (1) is shown below, this invention is not limited to these, It can synthesize | combine using conventionally well-known various routes and prescriptions.

  In 80 ml of toluene, 4.81 g of N, N'-diphenyloxalamine and 12.5 g of phosphorus pentachloride were added and heated under reflux for about 1 hour. The reaction solution was concentrated under reduced pressure to about 30 ml and then cooled to -20 ° C. The precipitated crystals were filtered and recrystallized from n-heptane to give 3.60 g (65.65 g) of N, N'-diphenyloxalimidoyl dichloride. 0%).

  To 20 ml of acetonitrile, 2.77 g of the obtained N, N′-diphenyloxalimidoyl dichloride, 0.95 g of acetamidine hydrochloride, and 3.54 g of triethylamine were added, and the mixture was heated to reflux for about 4 hours. After the reaction solution was cooled to room temperature, the produced triethylamine hydrochloride was removed by filtration, and the filtrate was concentrated and recrystallized from N, N-dimethylformamide to obtain Exemplified Compound (1).

  Other compounds represented by the general formulas (1) and (2) in the present invention can also be easily synthesized with reference to the above synthesis route.

《Metal salt compound》
The metal salt compound used in the present invention may be any compound as long as it can be dissolved and deposited reversibly by an electrochemical redox reaction between the counter electrodes. Preferred metal species are silver, bismuth, copper, nickel, iron, chromium, zinc and the like, more preferred are silver and bismuth, and particularly preferred is silver.

  In this embodiment, by applying a voltage of both positive and negative polarities between the counter electrodes, black and white display accompanying the dissolution and precipitation of the metal salt is performed, and in combination with the coloring / decoloring reaction by oxidation / reduction of the EC compound, Colored states other than white and black can be switched reversibly.

(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. In the display element of the present invention, the state species of the phase such as the solid state, the solubilized state in the liquid and the gas state, and the charged state species such as neutral, anionic and cationic are not particularly limited. Are preferably silver iodide, silver chloride, silver bromide, silver oxide, silver sulfide, silver citrate, silver acetate, silver behenate, silver p-toluenesulfonate, silver trifluoromethanesulfonate, mercaptos Known silver salt compounds such as silver salts and silver complexes with iminodiacetic acids can be used. Among these, it is preferable to use, as a silver salt, a compound that does not have a nitrogen atom having coordination properties with halogen, carboxylic acid, or silver, and for example, silver p-toluenesulfonate is preferable.

  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.

"Electrolytes"
The term “electrolyte” as used in the present invention generally refers to a substance that dissolves in a solvent such as water and exhibits 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”).

(Electrolyte solvent)
In the present invention, the electrolyte solvent is not particularly limited, and 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, di Tylene glycol, triethylene glycol monobutyl ether, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, dioxolane, sulfolane, diethyl ether, 1,2-dimethoxyethane, diethylene glycol dimeter ether, 2- Methyltetrahydrofuran, dioxane, methyldioxolanacetonitrile, benzonitrile, nitrobenzene, N, N-dimethylformamide, N, N-diethylformamide, sulfooxide, dimethylsulfoxide dimethylsulfone, tetramethylenesulfone, N-methyl-2-oxdorinoline , 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, particularly preferably used solvents are compounds represented by the following general formulas (S1) and (S2).

[Compounds Represented by General Formulas (S1) and (S2)]
In the display element of the present invention, the electrolyte preferably contains a compound represented by the following general formula (S1) or (S2).

In the formula, L represents an oxygen atom or an alkylene group, and Rs _{11 to} Rs ₁₄ each represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group, or an alkoxy group.

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

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

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

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

  Specific examples of the compound represented by the general formula (S1) are shown below, but the present invention is not limited to these exemplified compounds.

(Compound represented by formula (S2))
Next, the compound represented by formula (S2) will be described.

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

  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 (S2) are shown below, but the present invention is not limited to these exemplified compounds.

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

  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. As for the addition amount of ethylene carbonate, 10-90 mass% of the total electrolyte solvent mass is preferable. 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.

  In the present invention, a solid electrolyte may be used as the electrolyte. Polymers used in these solid electrolytes include polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-ethylene copolymer, vinylidene fluoride-monofluoroethylene copolymer, vinylidene fluoride- Vinylidene fluoride polymers such as trifluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, and acrylonitrile-methyl methacrylate copolymer Polymer, acrylonitrile-methyl acrylate copolymer, acrylonitrile-ethyl methacrylate copolymer, acrylonitrile-ethyl acrylate copolymer, acrylonitrile-methacrylic acid copolymer, acrylonitrile-acrylic acid Polymers, acrylonitrile - vinyl acetate copolymer, acrylonitrile-based polymer, further polyethylene oxide, ethylene oxide - propylene oxide copolymer, polymer and the like of these acrylates body or methacrylate products thereof. These polymers may be used as they are, but these polymers are gelled by adding an electrolyte solution, or gelled by adding a low-molecular gelling agent to the electrolyte solution. May be.

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

  There is no restriction | limiting in particular as salts, For example, inorganic ion salts, such as an alkali metal salt and alkaline-earth metal salt; Quaternary ammonium salt; Cyclic quaternary ammonium salt; Quaternary phosphonium salt etc. can be used.

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

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

Etc.

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

The supporting electrolyte of the present invention is preferably a quaternary ammonium salt, particularly preferably a quaternary spiro ammonium salt. As the counter anion, ClO ₄ ⁻ , BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , C ₂ F ₅ SO ₂ ) ₂ N ⁻ and PF ₆ ⁻ are preferable, and BF ₄ ⁻ is particularly preferable. The amount of electrolyte salt used is arbitrary, but in general, the upper limit of the electrolyte salt in the solvent is 20M or less, preferably 10M or less, more preferably 5M or less, and the lower limit is usually 0.01M or more. Preferably it is 0.05M or more, more preferably 0.1M or more.

《White scattering material》
In the present invention, from the viewpoint of further increasing the display contrast and the white display reflectance, a white scattering material is contained. However, 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 aluminum oxide 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 starch, gum arabic, dextran, pullulan, and carrageenan, and the like, polyvinyl alcohol, polyvinyl pyrrolidone, acrylamide polymers, and the like. Examples include synthetic polymer compounds such as derivatives. As gelatin derivatives, acetylated gelatin, phthalated gelatin, polyvinyl alcohol derivatives as terminal alkyl group-modified polyvinyl alcohol, terminal mercapto group-modified polyvinyl alcohol, and cellulose derivatives include hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose and the like. It is done. Further, Research Disclosure and those described on pages (71) to (75) of JP-A No. 64-13546, US Pat. No. 4,960,681, JP-A No. 62-245260, etc. superabsorbent polymers described, namely -COOM or -SO 3 M _(M is a hydrogen atom or an alkali metal) homopolymer or a vinyl monomer together or with other vinyl monomers of the vinyl monomer having a (e.g., sodium methacrylate, Copolymers with ammonium acid, potassium acrylate, etc.) are also used. 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 water-based solvents include natural rubber latex, styrene butadiene rubber, butadiene rubber, nitrile rubber, chloroprene rubber, isoprene rubber and other latexes, 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 not dissolved in an electrolyte solvent” is defined as a state in which a dissolution amount per kg of electrolyte solvent is 0 to 10 g at a temperature of −20 ° C. to 120 ° C. And the amount of dissolution can be determined by a known method such as a component quantification method using a gas chromatogram.

  In the present invention, the water 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.

  In the present invention, in addition to the electrolyte solvent and the supporting electrolyte, the following compounds may be added.

《Silver salt solvent》
In the display element of the present invention, in order to promote dissolution and precipitation of a metal salt (particularly a silver salt), the electrolyte is at least a compound represented by the following general formula (G-1) or general formula (G-2). It is preferable to contain 1 type.

  The compounds represented by the general formulas (G-1) and (G-2) are compounds that promote the solubilization of silver in the electrolyte in order to cause dissolution and precipitation of silver in the present invention. In general, in order to cause dissolution and precipitation of silver, it is necessary to solubilize silver in the electrolyte. For example, it causes a coordinate bond with silver or a weak covalent bond with silver. Compounds containing chemical structural species that interact with silver are useful. As the chemical structural species, a halogen atom, a mercapto group, a carboxyl group, an imino group, and the like are known, but in the present invention, a compound containing a thioether group and mercaptoazoles usefully function as a silver solvent, In addition, there is a feature that the influence on the coexisting compound is small and the solubility in the solvent is high.

(Compound represented by General Formula (G-1))
Formula _{(G-1) Rg 11 -S} -Rg 12
In the formula, Rg ₁₁ and Rg ₁₂ each represent a substituted or unsubstituted hydrocarbon group. These hydrocarbon groups may contain one or more nitrogen atoms, oxygen atoms, phosphorus atoms, sulfur atoms, and halogen atoms, and Rg ₁₁ and Rg ₁₂ may be linked to each other to take a cyclic structure.

  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.

  Specific examples of the compound represented by General Formula (G-1) according to the present invention are shown below, but the present invention is not limited to these exemplified compounds.

G1-1: CH ₃ SCH ₂ CH ₂ OH
G1-2: HOCH ₂ CH ₂ SCH ₂ CH ₂ OH
G1-3: HOCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OH
G1-4: HOCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OH
G1-5: HOCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ OH
_{G1-6: HOCH 2 CH 2 OCH 2} CH 2 SCH 2 CH 2 SCH 2 CH 2 OCH 2 CH 2 OH
G1-7: H ₃ CSCH ₂ CH ₂ COOH
G1-8: HOOCCH ₂ SCH ₂ COOH
G1-9: HOOCCH ₂ CH ₂ SCH ₂ CH ₂ COOH
G1-10: HOOCCH ₂ SCH ₂ CH ₂ SCH ₂ COOH
G1-11: HOOCCH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ COOH
G1-12: HOOCCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH (OH) CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ COOH
G1-13: 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
G1-14: H ₃ CSCH ₂ CH ₂ CH ₂ NH ₂
G1-15: H ₂ NCH ₂ CH ₂ SCH ₂ CH ₂ NH ₂
G1-16: H ₂ NCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NH ₂
G1-17: H ₃ CSCH ₂ CH ₂ CH (NH ₂ ) COOH
G1-18: H ₂ NCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ NH _{2
G1-19: H 2 NCH 2 CH 2} SCH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 SCH 2 CH 2 NH 2
G1-20: H ₂ NCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NH ₂
G1-21: HOOC (NH ₂ ) CHCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ CH (NH ₂ ) COOH
G1-22: HOOC (NH ₂ ) CHCH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH (NH ₂ ) COOH
G1-23: HOOC (NH ₂ ) CHCH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH (NH ₂ ) COOH
_{G1-24: H 2 N (= O} ) CCH 2 SCH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 SCH 2 C (= O) NH 2
_{G1-25: H 2 N (O =} ) CCH 2 SCH 2 CH 2 SCH 2 C (O =) NH 2
_{G1-26: H 2 NHN (O =} ) CCH 2 SCH 2 CH 2 SCH 2 C (= O) NHNH 2
_{G1-27: H 3 C (O =} ) NHCH 2 CH 2 SCH 2 CH 2 SCH 2 CH 2 NHC (O =) CH 3
_{G1-28: H 2 NO 2 SCH 2} CH 2 SCH 2 CH 2 SCH 2 CH 2 SO 2 NH 2
_{G1-29: NaO 3 SCH 2 CH 2} CH 2 SCH 2 CH 2 SCH 2 CH 2 CH 2 SO 3 Na
G1-30: H ₃ CSO ₂ NHCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NHO ₂ SCH ₃
G1-31: H ₂ N (NH) CSCH ₂ CH ₂ SC (NH) NH ₂ .2HBr
_{G1-32: H 2 (NH) CSCH} 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 SC (NH) NH 2 · 2HCl
G1-33: H ₂ N (NH) CNHCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NHC (NH) NH ₂ .2HBr
G1-34: [(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 G1-2 is particularly preferable from the viewpoint that the objective effect of the present invention can be exhibited.

(Compound represented by General Formula (G-2))
Next, the compound represented by formula (G-2) according to the present invention will be described.

In the formula, M represents a hydrogen atom, a metal atom or quaternary ammonium. Z represents an atomic group necessary for constituting a nitrogen-containing heterocyclic ring. n represents an integer of 0 to 5, Rg ₂₁ represents a substituent, and when n is 2 or more, each Rg ₂₁ may be the same or different, and may be connected to each other to form a condensed ring. It may be formed.

Examples of the metal atom represented by M 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.

  Examples of the nitrogen-containing heterocycle having Z as a component include, for example, a tetrazole ring, a triazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, an indole ring, an oxazole ring, a benzoxazole ring, a benzimidazole ring, a benzothiazole ring, Examples thereof include a benzoselenazole ring and a naphthoxazole ring.

The substituent represented by Rg ₂₁ is not particularly limited, and examples thereof include the following substituents.

  Halogen atom (eg, fluorine atom, chlorine atom, bromine atom, iodine atom) Alkyl group (eg, methyl, ethyl, propyl, i-propyl, butyl, t-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, octyl, dodecyl) , Hydroxyethyl, methoxyethyl, trifluoromethyl, benzyl, etc.), aryl groups (eg, phenyl, naphthyl, etc.), alkylcarbonamide groups (eg, acetylamino, propionylamino, butyroylamino, etc.), arylcarbonamide groups ( For example, benzoylamino etc.), alkylsulfonamide groups (eg methanesulfonylamino group, ethanesulfonylamino group etc.), arylsulfonamide groups (eg benzenesulfonylamino group, toluenesulfonylamino group etc.), Alkyloxy group (eg, phenoxy), alkylthio group (eg, methylthio, ethylthio, butylthio, etc.), arylthio group (eg, phenylthio group, tolylthio group, etc.), alkylcarbamoyl group (eg, methylcarbamoyl, dimethylcarbamoyl, ethylcarbamoyl, diethyl) Carbamoyl, dibutylcarbamoyl, piperidylcarbamoyl, morpholylcarbamoyl, etc.), arylcarbamoyl groups (eg, phenylcarbamoyl, methylphenylcarbamoyl, ethylphenylcarbamoyl, benzylphenylcarbamoyl, etc.), alkylsulfamoyl groups (eg, methylsulfamoyl, Dimethylsulfamoyl, ethylsulfamoyl, diethylsulfamoyl, dibutylsulfamoyl, piperidylsulfamoy , Morpholylsulfamoyl, etc.), arylsulfamoyl groups (eg, phenylsulfamoyl, methylphenylsulfamoyl, ethylphenylsulfamoyl, benzylphenylsulfamoyl, etc.), alkylsulfonyl groups (eg, methanesulfonyl) Group, ethanesulfonyl group, etc.), arylsulfonyl group (for example, phenylsulfonyl, 4-chlorophenylsulfonyl, p-toluenesulfonyl, etc.) alkoxycarbonyl group (for example, methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl, etc.), aryloxycarbonyl group ( For example, phenoxycarbonyl etc.), alkylcarbonyl groups (eg acetyl, propionyl, butyroyl etc.), arylcarbonyl groups (eg benzoyl group, alkylbenzoyl groups etc.), acyl Ruoxy group (for example, acetyloxy, propionyloxy, butyroyloxy, etc.), heterocyclic group (for example, oxazole ring, thiazole ring, triazole ring, selenazole ring, tetrazole ring, oxadiazole ring, thiadiazole ring, thiazine ring, triazine ring, Benzoxazole ring, benzthiazole ring, indolenine ring, benzselenazole ring, naphthothiazole ring, triazaindolizine ring, diazaindolizine ring, tetraazaindolizine ring group). These substituents further include those having a substituent.

  Next, although the preferable specific example of a compound represented by general formula (G-2) is shown, this invention is not limited to these compounds.

  Among the above-exemplified compounds, Exemplified Compounds G2-12 and G2-18 are particularly preferable from the viewpoint that the object and effects of the present invention can be exhibited.

<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 (a 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 (solvent) After forming a constituent layer with a binder or the like that is not soluble in organic solvents or inorganic substances and a solvent that is not soluble in a solvent, the organic substances or inorganic substances are dissolved in a solvent to obtain pores), a polymer or the like is heated or degassed, etc. Known forming methods such as a foaming method for foaming, a phase change method for phase separation of a mixture of polymers by operating a good solvent and a poor solvent, and a radiation irradiation method for forming pores 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.

《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
"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 to 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.

<< 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 used to seal the electrolyte so that it does not leak to the outside. It is also called a sealing agent. Epoxy resin, urethane resin, acrylic resin, vinyl acetate resin, ene-thiol resin, silicon A curing type such as a thermosetting type, a photocuring type, a moisture curing type, or an anaerobic curing type such as a resin or a modified polymer resin 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 maintain an appropriate interval between the substrates, such as an evenly spaced array, an array in which the interval gradually changes, and an array in which a predetermined arrangement pattern is repeated at a constant 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 for uniformly holding a gap between the substrates may be provided between the pair of 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 >>
In the display element of the present invention, it is preferable to display a black state by a cathode reaction, that is, by applying a voltage between the counter electrodes, the silver (salt) compound is reduced and blackened silver is precipitated. It is preferable to display the status.

  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 oxidation-reduction potential of the compound represented by the general formula (1) and the deposition overvoltage of metal ions.

  For example, in the case of a display element having a compound represented by the general formula (1) and a silver (salt) 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, by applying a noble voltage from the oxidation-reduction potential of the compound represented by the general formula (1), the compound represented by the general formula (1) is oxidized and other than black Shows a colored state and reduces the compound represented by the general formula (1) to a white state by applying a voltage between the redox potential of the compound represented by the general formula (1) and the precipitation overvoltage of the silver compound. By applying a voltage lower than the deposition overvoltage of the silver compound, silver is deposited on the electrode to show a black state, and the oxidation potential of the deposited silver and the redox of the compound represented by the general formula (1) There is a method of dissolving and decoloring the precipitated silver by applying a voltage between potentials.

  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. I mean. 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 a TFT circuit provided in each grid pattern. Since switching can be performed for each pixel, there are advantages such as gradation and memory function. For example, a circuit described in FIG. 5 of JP-A-2004-29327 can be used.

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

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

Example 1 (white, colored display (two colors))
<Production of display electrode>
[Display electrode]
(Production of electrode 1)
An ITO (Indium Tin Oxide) film having a pitch of 145 μm and an electrode width of 130 μm was formed on a 2 cm × 4 cm glass substrate having a thickness of 1.5 mm according to a known method to obtain a transparent electrode. On the transparent electrode, a titanium dioxide film having a thickness of 5 μm (about 4 to 10 particles having an average particle diameter of 17 nm had been necked) was formed to produce an electrode 1.

(Preparation of electrode 2)
The following ink liquid 1 was applied onto the electrode 1 at 120 dpi by an inkjet apparatus having a piezo-type head, and an electrode 2 was produced. In addition, dpi represents the number of dots per 2.54 cm.

(Preparation of electrode 3)
The electrode 3 was produced in the same manner as in the production of the electrode 2 except that the ink liquid 1 was changed to the ink liquid 2.

(Preparation of electrode 4)
The electrode 1 was loaded with about 100 mg / cm ^{2 of the following} adsorbent 1 on titanium dioxide, allowed to stand at room temperature for about 1 hour, washed with ethanol and water, and then heated at 100 ° C. for about 1 hour. Produced.

(Production of electrodes 5 and 6)
Electrodes 5 and 6 were produced in the same manner except that the adsorbing liquid 1 was changed to the adsorbing liquids 2 and 3 in the production of the electrode 4.

(Preparation of ink liquid 1)
The ink compound 1 was prepared by dissolving the exemplified compound (5) in acetonitrile / ethanol to 3 mmol / l.

(Preparation of ink liquid 2)
In the production of the adsorbing liquid 1, the adsorbing liquid 2 was prepared in the same manner except that the exemplified compound (5) was changed to the exemplified compound (15).

(Preparation of adsorbent 1)
To a place where 0.02 g of acetic acid, 1 g of pure water and 1 g of methanol are being stirred, a solution prepared by dissolving 0.005 g of Exemplified Compound (38) in 0.15 g of methanol is added dropwise and stirred at room temperature for about 1 hour. 1 was prepared.

(Preparation of adsorbent 2)
The adsorbing liquid 2 was prepared in the same manner as in the preparation of the adsorbing liquid 1 except that the exemplary compound (38) was changed to the exemplary compound (59).

(Preparation of adsorbent 3)
In the production of the adsorbing liquid 1, the adsorbing liquid 3 was prepared in the same manner except that the exemplified compound (38) was changed to the comparative compound B.

[Counter electrode]
(Preparation of electrode 7)
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. And a gold-nickel electrode (electrode 10) having a depth of 0.05 μm replaced with gold from the electrode surface was obtained.

(Preparation of electrolyte)
(Preparation of electrolyte 1)
In 2.5 g of γ-butyrolactone, 0.025 g of spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate and carboxy TEMPO (4-carboxy-2,2,6,6-tetramethylpiperidine-1-oxyl free Radical) 0.05 g was dissolved to obtain an electrolyte solution 1.

(Preparation of electrolyte 2)
In the preparation of the electrolytic solution 1, an electrolytic solution 2 was prepared in the same manner except that 0.1 g of the exemplified compound (1) was further dissolved.

(Preparation of electrolyte 3)
In the preparation of the electrolytic solution 2, an electrolytic solution 3 was prepared in the same manner except that the exemplified compound (1) was changed to the comparative compound A.

(Preparation of electrolyte 5)
An electrolytic solution 5 was prepared in the same manner as in the preparation of the electrolytic solution 2 except that the exemplified compound (1) was changed to the comparative compound C.

<< Production of display element >>
(Preparation of display element 1)
On the periphery of the electrode 7 bordered by an olefin-based sealant containing 10% glass spherical bead spacers having an average particle diameter of 40 μm as a volume fraction, polyvinyl alcohol (average polymerization degree 3500, saponification degree 87% ) Add 20% by mass of titanium dioxide CR-90 made by Ishihara Sangyo Co., Ltd. into an isopropanol solution containing 2% by mass, and apply the mixed liquid dispersed with an ultrasonic disperser so that the film thickness after drying is 20 μm. Then, after drying at 15 ° C. for 30 minutes to evaporate the solvent, it was dried in an atmosphere at 45 ° C. for 1 hour. After sprinkling glass spherical bead spacers having an average particle diameter of 20 μm on the obtained titanium dioxide layer, electrodes 6 and 1 were bonded together and heated and pressed to produce empty cells. The electrolytic solution 2 was vacuum-injected into the empty cell, and the injection port was sealed with an epoxy-based ultraviolet curable resin to produce the display element 1.

(Production of display elements 2 to 5)
In the production of the display element 1, display elements 2 to 5 were obtained in the same manner except that the electrode 1 was changed to the electrodes 2 to 5 and the electrolytic solution 2 was changed to the electrolytic solution 1.

(Preparation of display element 6)
A display element 6 was obtained in the same manner as in the production of the display element 1 except that the electrolytic solution 1 was changed to the electrolytic solution 3.

(Preparation of display element 7)
A display element 7 was obtained in the same manner as in the production of the display element 1 except that the electrode 1 was changed to the electrode 6 and the electrolytic solution 2 was changed to the electrolytic solution 1.

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

<< Evaluation of display element >>
(Evaluation of reflectance stability and memory performance when driven repeatedly)
Connect both electrodes of the display element to both terminals of the constant voltage power supply, and for display elements 1 to 7, apply a voltage of -1.5 V for 1.5 seconds, and then apply a voltage of +1.5 V for 1 second. When the color display is performed, the reflectance at the maximum absorption wavelength in the visible light region is measured with a spectrocolorimeter CM-3700d manufactured by Konica Minolta Sensing Co., and a voltage of +1.5 V is applied to the display element 8 Was applied for 1.5 seconds, and then a voltage of -1.5 V was applied for 1 second for color display, and when the display was decolored, the reflectance at the maximum absorption wavelength in the visible light region was manufactured by Konica Minolta Sensing Co., Ltd. Measurement was performed with a spectrocolorimeter CM-3700d. Under the same driving conditions, driving was performed 10 times in total, and the average value of the obtained reflectances was defined as R _ave3 . Further, after driving repeatedly 10,000 times, R _ave4 was obtained by the same method. ΔR _color2 = | R _ave3 -R _ave4 | was used as an index of stability of reflectance when ΔR _{color 2} was repeatedly driven. Here, the smaller the value of ΔR _color2 , the _better the stability of the reflectance when it is repeatedly driven. Further, the voltage was cut off after the color display, and whether or not the color state was maintained after 10 minutes was visually evaluated based on the following criteria for the memory property.

◯: Colored state is maintained Δ: Colored but a decrease in density is observed ×: Colored state is not maintained Table 1 shows the evaluation results of each display element obtained as described above.

With respect to the display element 6, since there was no absorption in the visible region, ΔR _color2 (%) and the memory property could not be evaluated.

  As is apparent from the results shown in Table 1, the EC compound of the present invention has a color tone in the visible region during coloring, improved memory properties, and stability of reflectance when repeatedly driven, compared to the comparative example. You can see that it has improved. In addition, it can be seen that the EC compound of the present invention is excellent in process suitability when producing a display element because there is no precipitate after stirring the electrolyte solution for 10 minutes and the solubility is good. .

Example 2 (white, black, colored display evaluation (three colors))
<< Preparation of electrolyte >>
(Preparation of electrolyte 6)
2.5 g of γ-butyrolactone, 0.025 g of spiro- (1,1 ′)-bipyrrolidinium tetrafluoroborate as a supporting electrolyte, 0.1 g of silver p-toluenesulfonate as a metal salt compound, and exemplified compound G1 as a silver salt solvent -3 0.2 g and 0.05 g of carboxy TEMPO (4-carboxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical) as a promoter were added to prepare an electrolytic solution 6.

<< Production of display element >>
(Preparation of display element 9)
A display element 9 was obtained in the same manner as in the production of the display element 1 of Example 1, except that the electrode 1 was changed to the electrode 2 and the electrolytic solution 2 was changed to the electrolytic solution 6.

(Preparation of display elements 10-13)
In the production of the display element 9, display elements 10 to 13 were obtained in the same manner except that the electrode 2 was changed to the electrodes 3 to 6.

<< Evaluation of display element >>
[Evaluation of reflectance stability when driven repeatedly]
Connect both electrodes of the display element to both terminals of the constant voltage power supply, apply a voltage of -1.5 V for 1.5 seconds and display in gray, and a wavelength of 550 nm and a voltage of +1.5 V are 1.5. The reflectance at the maximum absorption wavelength in the visible light region when colored for display for 2 seconds was measured with a spectrocolorimeter CM-3700d manufactured by Konica Minolta Sensing. It was driven a total of 10 times under similar driving conditions, and the average values of the obtained gray reflectance and colored reflectance were calculated separately, and were _designated as R _ave3 and R _ave4 , respectively. Was determined _{R ave5, R ave6} respectively in the same manner after further 10,000 iterations driven.
ΔR _BK = | R _ave3 -R _ave5 |,
ΔR _color2 = | R _ave4 -R _ave6 |, and ΔR _BK and ΔR _{color 2} were used as an index of the stability of the reflectance when it was repeatedly driven. Here, the smaller the values of ΔR _BK and ΔR _color2 , the _better the stability of the reflectance when it is repeatedly driven.

[Evaluation of display element uniformity (unevenness)]
After extending the number of repetitions of the evaluation of the stability of the reflectance when repeatedly driven to 1 million times, the state of unevenness of the display element was visually evaluated according to the following criteria.

○: A substantially uniform color development / decoloration state is maintained. Δ: Discoloration or density unevenness is observed. ×: Discoloration or density unevenness is remarkable. XX: The element does not drive (the density does not change when voltage is applied).
Table 4 shows the evaluation results of the electrolytic solutions and display elements obtained as described above.

  As is apparent from the results shown in Table 2, the display element satisfying the configuration of the present invention can display three colors of white, black, and coloring. It can be seen that the stability of the reflectance in the colored state, display unevenness and the like are improved.

It is a schematic sectional drawing which shows an example of a structure of the display element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display element 2 Display electrode 3 Counter electrode 4 Display layer 5 Electrolyte 6 White reflection layer

Claims (9)

An electrochromic compound, a metal salt compound, an electrolyte, and a white scatterer are contained between the counter electrodes, and the multi-color display of three or more colors of black display, white display, and color display other than black is performed by driving the counter electrode. In the display element, the electrochromic compound is represented by the following general formula (1) or (2).

(In the formula, R _{1 to} R ₆ represent a hydrogen atom or a substituent, but at least one of R _{1 to} R ₆ represents a substituent, R ₁ and R ₂ , R ₃ and R ₄ , R ₅ and R ₆ is not bonded to each other to form a ring, X ₁ and X ₂ represent —NR ₉ —, —O—, or —S—, n represents an integer of 1 to 3, and R ₉ represents a hydrogen atom. Or represents a substituent.)

(Wherein R ₇ and R ₈ represent a hydrogen atom or a substituent, and R ₇ and R ₈ may be linked together to form a 5- to 6-membered ring. X ₁ and X ₂ are —NR ₉ represents -O- or -S-, m represents an integer of 0 to 3, R ₉ represents a hydrogen atom or a substituent, and A and B are necessary for forming a 5- to 6-membered ring. Represents an atomic group.) _2. The display element according to claim ₁ , wherein in the general formula (1), X ₁ and X ₂ are both NH. The display element according to claim 1, wherein the metal salt compound is a silver salt compound. The display element according to claim 1, wherein the electrochromic compound is carried on at least one surface of the counter electrode. The electrochromic compound is selected from CO ₂ H, —PO (OH) ₂ , —OPO (OH) ₂ , —SO ₃ H, and —Si (OR) ₃ (R represents a hydrogen atom or an alkyl group). The display element according to claim 1, wherein the display element has at least one substituent. The display element according to claim 1, wherein at least one of the counter electrodes is made of a metal oxide porous layer, and an electrochromic compound is supported on the metal oxide porous layer. . The display element according to claim 1, wherein the white scatterer includes TiO ₂ , ZnO, or Al ₂ O ₃ . The display element according to claim 1, wherein a black state is displayed by a cathode reaction. The display element according to any one of claims 1 to 8, wherein the colored display other than black is a color display by arranging a display area having different hues on a plane.

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