JP2011102287A - Electrochromic compound, electrochromic composition, and display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrochromic compound and electrochromic composition which show sharp light absorption spectral characteristics in color development, and present yellow based, cyan based, and black based color developments, and to provide a display element using the electrochromic compound or electrochromic composition. <P>SOLUTION: The electrochromic compound is represented by formula (1). In the formula (1), X<SB>1</SB>, X<SB>2</SB>, X<SB>3</SB>, and X<SB>4</SB>each independently denote a hydrogen atom or a monovalent substituent, n denotes the integer of 1 to 6, Rs each independently denote a monovalent substituent, and Ar denotes a benzene ring which may have a substituent when n is from 1 to 5, and only a benzene ring when n is 6, and A<SP>-</SP>denotes a monovalent anion. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electrochromic compound, an electrochromic composition, and a display element using the electrochromic compound or electrochromic composition that exhibit yellow, cyan, or black coloration during color development.

In recent years, electronic paper has been actively developed as an electronic medium replacing paper.
Since electronic paper is characterized in that the display device is used like paper, characteristics different from those of conventional display devices such as CRT (Cathode Ray Tube) and liquid crystal display are required. For example, it is a reflection type display device, has a high white reflectance and a high contrast ratio, can display a high definition, has a memory effect in display, can be driven even at a low voltage, is thin and light, and is inexpensive It is necessary to have characteristics such as Of these, the white reflectance / contrast ratio equivalent to that of paper and the demand for color display are particularly high as characteristics relating to display quality.

  Until now, as a display device for electronic paper, for example, a method using a reflective liquid crystal, a method using electrophoresis, a method using toner migration, and the like have been proposed. However, it is very difficult for any of the above methods to perform multicolor display while ensuring white reflectance / contrast ratio. In general, in order to perform multicolor display, a color filter is provided. However, when a color filter is provided, the color filter itself absorbs light, and the reflectance decreases. Furthermore, since the color filter divides one pixel into red (R), green (G), and blue (B), the reflectance of the display device is lowered, and the contrast ratio is lowered accordingly. When the white reflectance / contrast ratio is significantly reduced, the visibility is very poor and it is difficult to use as electronic paper.

Patent Documents 1 and 2 disclose a reflective color display medium in which a color filter is formed on an electrophoretic element. However, even if a color filter is formed on a display medium having a low white reflectance and a low contrast ratio, good image quality It is clear that cannot be obtained.
Further, Patent Documents 3 and 4 disclose an electrophoretic element that performs colorization by moving particles colored in a plurality of colors, but in principle, these methods are used as described above. However, it cannot solve the problem of high reflectance and contrast, and cannot satisfy both high white reflectance and high contrast ratio at the same time.

On the other hand, as a promising technique for realizing a reflective display device without providing the color filter as described above, there is a method using an electrochromic phenomenon.
A phenomenon in which a redox reaction occurs reversibly and a color changes reversibly by applying a voltage is called electrochromism. An electrochromic display device is a display device that utilizes the coloring / decoloring (hereinafter referred to as color erasing) of an electrochromic compound that causes this electrochromic phenomenon. Since this electrochromic display device is a reflective display device, has a memory effect, and can be driven at a low voltage, it is a leading candidate for display device technology for electronic paper use, from material development to device design. R & D has been conducted extensively.

  However, the electrochromic display device has a drawback in that the response speed of color development / decoloration is slow because of the principle of performing color development / decoloration using an oxidation-reduction reaction. Patent Document 5 describes an example in which an electrochromic compound is fixed in the vicinity of an electrode to improve the response speed of color development and decoloration. According to the description in Patent Document 5, the time required for color development and decoloration, which has been about several tens of seconds, has been improved to about 1 second for both the color development time from colorless to blue and the color elimination time from blue to colorless. Yes. However, this is not sufficient, and in the research and development of electrochromic display devices, it is necessary to further improve the response speed of color development and decoloration.

  An electrochromic display device is expected as a multicolor display device because it can generate various colors depending on the structure of the electrochromic compound. In particular, since the colorless state and the color development state are reversibly changed, a stacked multicolor configuration can be realized. In color display in a stacked configuration, it is not necessary to divide one pixel into red (R), green (G), and blue (B) as in the prior art, so the reflectance and contrast ratio of the display device do not decrease.

  There are some known examples of multicolor display devices using such electrochromic display devices. For example, Patent Document 6 discloses a multicolor display device using an electrochromic compound in which fine particles of a plurality of types of electrochromic compounds are stacked. This Patent Document 6 describes an example of a multicolor display device in which a plurality of electrochromic compounds, which are polymer compounds having a plurality of functional functional groups with different voltages that exhibit color development, are laminated to form a multicolor display electrochromic compound. ing.

  Further, Patent Document 7 discloses a display device in which a plurality of electrochromic layers are formed on an electrode, and multiple colors are developed using a difference in voltage value or current value necessary for color development. In this patent document 7, a multicolor display device having a display layer formed by laminating or mixing a plurality of electrochromic compounds which develop different colors and have different threshold voltages for color development and different charge amounts necessary for color development. Examples are described.

  Further, Patent Document 8 describes an example of a multicolor display device in which a plurality of structural units each having an electrochromic layer and an electrolyte sandwiched between a pair of transparent electrodes are stacked. Further, Patent Document 9 describes an example of a multicolor display device corresponding to RGB three colors by forming a passive matrix panel and an active matrix panel using the structural units described in Patent Document 8.

However, the viologen-based organic electrochromic compounds exemplified in Patent Documents 5, 6 and 7 develop blue and green, and do not develop the three primary colors yellow, magenta and cyan necessary for full colorization. . In order to develop the three primary colors, it is necessary to have sharp absorption at the time of color development. In particular, yellow color development must have sharp absorption in the short wavelength region, and yellow color development is possible and stable color development is possible. Electrochromic compounds have not been obtained so far.
In addition, cyan color development must have sharp absorption in the long wavelength region, and an electrochromic compound capable of cyan color development and stable color development / decoloration has not been obtained so far.
Furthermore, an electrochromic compound that develops black having absorption in the entire wavelength range of visible light has not been obtained so far. If there is an electrochromic compound that produces black color, a monochrome display element with high contrast can be produced.
Further, in Patent Documents 8, 9, and 10, YMC color development is made possible by using a styryl dye, but there is a problem in the stability of color development and repeated durability.

  The present invention has been made in view of the above problems in the prior art, and shows an electrochromic compound and an electrochromic compound that exhibit sharp light absorption spectral characteristics during color development and exhibit color development in any of yellow, cyan, and black. It is an object of the present invention to provide a chromic composition and a display element using the electrochromic compound or the electrochromic composition.

  As a result of intensive studies, the present inventors have found that the above problems can be solved by at least a specific electrochromic compound, and have completed the present invention.

Specifically, the electrochromic compound and the electrochromic composition according to the present invention for solving the above-described problems, and the display device using the electrochromic compound or the electrochromic composition are specifically described in the following (I) to (IV ).
(I): An electrochromic compound represented by any one of the following general formulas (1) to (4).

(In the general formula (1), X ₁ , X ₂ , X ₃ and X ₄ each independently represent a hydrogen atom or a monovalent substituent, R independently represents a monovalent substituent, and n represents 1 represents an integer of 1 to 6, Ar represents a benzene ring which may have a substituent when n is 1 to 5, and simply represents a benzene ring when n is 6, and A ⁻ represents a monovalent anion. Represents.)

(In the general formula (2), X ₁ , X ₂ , X ₃ , X ₄ , X ₅ , X ₆ , X ₇ , X ₈ , Y ₁ , Y ₂ , Y ₃ , Y ₄ are each independently a hydrogen atom. Alternatively, it represents a monovalent substituent, R ₁ and R ₂ each independently represent a monovalent substituent, and A ⁻ represents a monovalent anion.)

(In the general formula (3), X ₁ , X ₂ , X ₃ , X ₄ , X ₅ , X ₆ , X ₇ , X ₈ , Y ₁ , Y ₂ , Y ₃ , Y ₄ are each independently a hydrogen atom. Alternatively, it represents a monovalent substituent, R ₁ and R ₂ each independently represent a monovalent substituent, and A ⁻ represents a monovalent anion.)

(In the general formula (4), X ₁ , X ₂ , X ₃ , X ₄ , X ₅ , X ₆ , X ₇ , X ₈ , Y ₁ , Y ₂ are each independently a hydrogen atom or a monovalent substituent. R ₁ and R ₂ each independently represents a monovalent substituent, and A ⁻ represents a monovalent anion.)

(II): At least one of R or at least one of R ₁ and R ₂ is a functional group capable of binding directly or indirectly to a hydroxyl group. It is an electrochromic compound as described in said (I).

(III): An electrochromic composition comprising a conductive or semiconducting nanostructure and the electrochromic compound according to (II) above that is bonded or adsorbed to the nanostructure. .

(IV): a display electrode, a counter electrode provided in a state of being opposed to the display electrode, and an electrolyte disposed between the display electrode and the counter electrode,
A display layer on a surface of the display electrode facing the counter electrode;
The display layer is a display element comprising at least the electrochromic compound described in (I) or (II) above or the electrochromic composition described in (III) above.

  ADVANTAGE OF THE INVENTION According to this invention, the electrochromic compound and electrochromic composition which exhibit yellow color development, cyan color development, or black color development can be provided. In addition, according to the present invention, since the electrochromic compound or the electrochromic composition is used, a display element capable of full color display can be provided.

It is the schematic which shows the structural example of the general display element using the electrochromic compound which concerns on this invention, (a) is an electrochromic compound which does not have an adsorption group, (b) is an electrochromic which has an adsorption group The case of a compound is shown. It is a schematic diagram which shows the structure of the electrochromic compound which has an adsorption group. It is the schematic which shows the structural example of the general display element using the electrochromic composition which concerns on this invention. 3 is a graph showing a spectrum when coloring the electrochromic display element produced in Example 1. FIG. 6 is a graph showing the result of CIE color system coordinate conversion of the spectrum at the time of color development of the electrochromic display device produced in Example 1. 2 is a graph showing absorption spectra before and after voltage application of the electrochromic display layer produced in Example 1. FIG. 6 is a graph showing a spectrum at the time of color development of the electrochromic display element produced in Example 2. It is a graph which shows the result of having carried out the CIE color system coordinate conversion of the spectrum at the time of color development of the electrochromic display element produced in Example 2. FIG. 6 is a graph showing absorption spectra before and after voltage application of the electrochromic display layer produced in Example 2. 6 is a graph showing a spectrum at the time of color development of the electrochromic display element produced in Example 7. It is a graph which shows the result of having carried out the CIE color system coordinate conversion of the spectrum at the time of color development of the electrochromic display element produced in Example 7. FIG. 6 is a graph showing absorption spectra before and after voltage application of an electrochromic display layer produced in Example 7. 10 is a graph showing a spectrum at the time of color development of the electrochromic display element produced in Example 9. It is a graph which shows the result of having carried out the CIE color system coordinate conversion of the spectrum at the time of color development of the electrochromic display element produced in Example 9. FIG. It is a graph which shows the absorption spectrum before and behind the voltage application of the electrochromic display layer produced in Example 9. FIG. 6 is a graph showing a spectrum at the time of color development of the electrochromic display element produced in Comparative Example 1.

<Electrochromic compound, electrochromic composition>
The electrochromic compound according to the present invention is represented by any one of the following general formulas (1) to (4).

In the general formula (1), X ₁ , X ₂ , X ₃ , and X ₄ each independently represent a hydrogen atom or a monovalent substituent, each R independently represents a monovalent substituent, and n is 1 Represents an integer from 1 to 6, Ar represents an optionally substituted benzene ring when n is from 1 to 5, and simply represents a benzene ring when n is 6, A ⁻ represents a monovalent anion. To express.

(In the general formula (2), X ₁ , X ₂ , X ₃ , X ₄ , X ₅ , X ₆ , X ₇ , X ₈ , Y ₁ , Y ₂ , Y ₃ , Y ₄ are each independently a hydrogen atom. Alternatively, it represents a monovalent substituent, R ₁ and R ₂ each independently represent a monovalent substituent, and A ⁻ represents a monovalent anion.)

  The electrochromic compound represented by the general formula (2) exhibits a sharp light absorption spectrum characteristic at the time of color development and exhibits yellow color development.

(In the general formula (3), X ₁ , X ₂ , X ₃ , X ₄ , X ₅ , X ₆ , X ₇ , X ₈ , Y ₁ , Y ₂ , Y ₃ , Y ₄ are each independently a hydrogen atom. Alternatively, it represents a monovalent substituent, R ₁ and R ₂ each independently represent a monovalent substituent, and A ⁻ represents a monovalent anion.)

  The electrochromic compound represented by the general formula (3) exhibits a sharp light absorption spectrum characteristic at the time of color development and exhibits cyan color development.

(In the general formula (4), X ₁ , X ₂ , X ₃ , X ₄ , X ₅ , X ₆ , X ₇ , X ₈ , Y ₁ , Y ₂ are each independently a hydrogen atom or a monovalent substituent. R ₁ and R ₂ each independently represents a monovalent substituent, and A ⁻ represents a monovalent anion.)

  The electrochromic compound represented by the general formula (4) exhibits a broad light absorption spectrum characteristic in the entire wavelength region during color development, and exhibits black color development.

Specific examples of X ₁ , X ₂ , X ₃ , X ₄ , X ₅ , X ₆ , X ₇ , X ₈ , Y ₁ , Y ₂ , Y ₃ , Y ₄ include a hydrogen atom, a halogen atom, a hydroxyl group, Nitro group, cyano group, carboxyl group, optionally substituted alkoxycarbonyl group, optionally substituted aryloxycarbonyl group, optionally substituted alkylcarbonyl group, substituted An arylcarbonyl group which may have a group, an amide group, a monoalkylaminocarbonyl group which may have a substituent, a dialkylaminocarbonyl group which may have a substituent, and a substituent. A monoarylaminocarbonyl group which may have a substituent, a diarylaminocarbonyl group which may have a substituent, a sulfonic acid group, an alkoxysulfonyl group which may have a substituent, a substituent An optionally substituted aryloxysulfonyl group, an optionally substituted alkylsulfonyl group, an optionally substituted arylsulfonyl group, a sulfonamide group, and an optionally substituted mono Alkylaminosulfonyl group, optionally substituted dialkylaminosulfonyl group, optionally substituted monoarylaminosulfonyl group, optionally substituted diarylaminosulfonyl group, amino group A monoalkylamino group which may have a substituent, a dialkylamino group which may have a substituent, an alkyl group which may have a substituent, an alkenyl which may have a substituent Group, alkynyl group which may have a substituent, aryl group which may have a substituent, alkoxy group which may have a substituent, substituent An aryloxy group that may have, an alkylthio group that may have a substituent, an arylthio group that may have a substituent, a heterocyclic group that may have a substituent, and the like. .

The group represented by X ₁ , X ₂ , X ₃ , X ₄ , X ₅ , X ₆ , X ₇ , X ₈ can impart solubility to the solvent of the electrochromic compound, so that the device fabrication process is easy become. Further, fine adjustment of the color development spectrum (color) becomes possible. On the other hand, the stability such as heat resistance and light resistance is likely to be lowered by these groups. Therefore, a hydrogen atom, halogen, or a substituent having 6 or less carbon atoms is preferable. Particularly preferred are a hydrogen atom and a substituent having 3 or less carbon atoms.

Specific examples of R, R ₁ and R ₂ include an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, and a substituent. Examples thereof include an aryl group which may have a group. Further, at least one of R, R ₁ and R ₂ may be a functional group capable of binding directly or indirectly to the hydroxyl group.
The functional group that can be directly or indirectly bonded to the hydroxyl group may be any functional group that can be directly or indirectly bonded to the hydroxyl group by hydrogen bonding, adsorption or chemical reaction, and the structure is limited. However, preferred examples include phosphonic acid groups, phosphoric acid groups, carboxyl groups, trichlorosilyl groups, trialkoxysilyl groups, monochlorosilyl groups, monoalkoxysilyl groups, and the like. The trialkoxysilyl group is preferably a triethoxysilyl group or a trimethoxysilyl group.
Of these, trialkoxysilyl groups and phosphonic acid groups (which will be described later) having a high binding force to conductive or semiconducting nanostructures are particularly preferable.

A ⁻ represents a monovalent anion and is not particularly limited as long as it stably forms a pair with the cation moiety, but Br ion, Cl ion, ClO ₄ ion, PF ₆ ion, BF ₄ ion, etc. preferable. Particularly preferred are Br ions and Cl ions.

The electrochromic compound of the present invention is preferably X _{1 to} X ₈ and R that have a symmetrical structure from the viewpoint of ease of synthesis and stability improvement.

  Examples of specific structural formulas (5) to (58) of the electrochromic compound of the present invention are shown below, but the electrochromic compound of the present invention is not limited to these.

  In addition, the electrochromic composition according to the present invention has an electrochromic compound of the present invention (an electrochromic compound represented by any one of the general formulas (1) to (4)) on a conductive or semiconducting nanostructure. It is characterized by being bound or adsorbed. When used in an electrochromic display device, the electrochromic composition of the present invention exhibits yellow, cyan, or black color development, and further has excellent image memory properties, that is, color development image retention characteristics. Note that the conductive or semiconducting nanostructure is a structure having nanoscale unevenness such as a nanoparticle or a nanoporous structure.

  When the electrochromic compound of the present invention has a sulfonic acid group, a phosphoric acid group or a carboxyl group as an adsorbing structure, the electrochromic compound is easily complexed with the nanostructure and has excellent color image retention. It becomes. A plurality of the sulfonic acid group, phosphoric acid group and carboxyl group may be present in the compound.

  Alternatively, when the electrochromic compound of the present invention is bonded to the nanostructure through a silanol bond, the bond becomes strong, and a stable electrochromic composition is obtained. The silanol bond here is a chemical bond through a silicon atom and an oxygen atom. In addition, the electrochromic composition only needs to have a structure in which the electrochromic compound and the nanostructure are bonded via a silanol bond, and the bonding method and form thereof are not particularly limited.

  The material constituting the conductive or semiconducting nanostructure is preferably a metal oxide in terms of transparency and conductivity. Examples of the metal oxide include titanium oxide, zinc oxide, tin oxide, aluminum oxide (hereinafter referred to as alumina), zirconium oxide, cerium oxide, silicon oxide (hereinafter referred to as silica), yttrium oxide, boron oxide, Magnesium oxide, strontium titanate, potassium titanate, barium titanate, calcium titanate, calcium oxide, ferrite, hafnium oxide, tungsten oxide, iron oxide, copper oxide, nickel oxide, cobalt oxide, barium oxide, strontium oxide, vanadium oxide Metal oxides mainly composed of aluminosilicate, calcium phosphate, aluminosilicate and the like are used. Moreover, these metal oxides may be used independently and 2 or more types may be mixed and used. In view of electrical properties such as electrical conductivity and physical properties such as optical properties, it is selected from titanium oxide, zinc oxide, tin oxide, alumina, zirconium oxide, iron oxide, magnesium oxide, indium oxide, and tungsten oxide. When one kind or a mixture thereof is used, multicolor display excellent in response speed of color development and decoloration is possible. In particular, when titanium oxide is used, it is possible to display a multicolored color with an excellent response speed of color development and decoloration.

The shape of the metal oxide is preferably metal oxide fine particles having an average primary particle diameter of 30 nm or less. As the particle diameter is smaller, the light transmittance to the metal oxide is improved, and the surface area per unit volume (hereinafter referred to as “specific surface area”) is increased. By having a large specific surface area, the electrochromic compound is more efficiently supported, and a multicolor display with an excellent display contrast ratio for color development and decoloration is possible. Although the specific surface area of a nanostructure is not specifically limited, For example, it can be 100 m < ² > / g or more.

<Display element>
Next, the display element according to the present invention will be described.
FIG. 1 shows a configuration example of a general display element using the electrochromic compound of the present invention. As shown in FIGS. 1 (a) and 1 (b), the display elements 10 and 20 of the present invention are provided so that the display electrode 1 is opposed to the display electrode 1 with a space therebetween. The electrode 2 and an electrolyte 3 disposed between the electrodes 1 and 2 (display electrode 1 and counter electrode 2), and the surface of the display electrode 1 on the counter electrode 2 side (the surface facing the counter electrode 2) The display layer 4a includes at least the electrochromic compound 5a of the present invention.

  In the display element of FIG. 1B, the display layer 4a is formed on the surface of the display electrode 1 on the counter electrode 2 side using the electrochromic compound 5a of the present invention. As the formation method, any method such as immersion, dipping method, vapor deposition method, spin coating method, printing method, ink jet method and the like may be used. As shown in FIG. 2, when the electrochromic compound 5a of the present invention has an adsorptive group (bonding group) 5c due to its molecular structure, the adsorbing group 5c is adsorbed on the display electrode 1, and the display layer 4a. Is formed. At this time, as shown in FIG. 2, the redox coloring portion 5b that develops color is connected to the adsorbing group 5c through the spacer portion 5d, and the electrochromic compound 5a is constituted by these.

  Moreover, it is also possible to make it the solution structure which melt | dissolved electrolyte in the solvent like Fig.1 (a), and also to dissolve the electrochromic compound 5a in the said solution. In this case, the electrochromic compound 5a develops and discolors only by the oxidation-reduction reaction on the electrode surface. That is, in the solution containing the electrochromic compound, the surface of the display electrode 1 facing the counter electrode 2 functions as the display layer 4a.

  FIG. 3 shows a configuration example of a general display element using the electrochromic composition 5e of the present invention. As shown in FIG. 3, the display element 30 of the present invention includes a display electrode 1, a counter electrode 2 provided facing the display electrode 1 at a distance, and both electrodes 1 and 2 (displays). And an electrolyte 3 disposed between the electrode 1 and the counter electrode 2), and on the surface of the display electrode 1 on the counter electrode 2 side (the surface facing the counter electrode 2), at least the electrochromic composition 5e of the present invention. Has a display layer 4b. In addition, a white reflective layer 6 made of white particles is provided on the display electrode 1 side of the counter electrode 2 (on the side facing the display electrode 1).

  In the display element shown in FIG. 3, the display layer 4b is formed on the surface of the display electrode 1 on the counter electrode 2 side using the electrochromic composition 5e of the present invention. As the formation method, any method such as immersion, dipping method, vapor deposition method, spin coating method, printing method, ink jet method and the like may be used. As shown in FIG. 2, the electrochromic compound 5a in the electrochromic composition 5e of the present invention has a bonding group 5c in terms of molecular structure, and the bonding group 5c is present on the conductive or semiconducting nanostructure. The electrochromic composition 5e is formed by bonding. The electrochromic composition 5e is provided on the display electrode 1 in a layered manner to form the display layer 4b.

  Next, materials used for the electrochromic display elements 10, 20, and 30 according to the embodiment of the present invention will be described.

  As the display electrode 1, it is desirable to use a transparent conductive substrate. The transparent conductive substrate is preferably glass or a plastic film coated with a transparent conductive thin film. If a plastic film is used, a lightweight and flexible display element can be produced.

The transparent conductive thin film material is not particularly limited as long as it is a conductive material, but a transparent conductive material that is transparent and excellent in conductivity is used because it is necessary to ensure light transmission. . Thereby, the visibility of the color to develop can be improved more. Examples of the transparent conductive material include indium oxide doped with tin (hereinafter referred to as ITO), tin oxide doped with fluorine (hereinafter referred to as FTO), and tin oxide doped with antimony (hereinafter referred to as ATO). An inorganic material can be used, but in particular, an indium oxide (hereinafter referred to as In oxide), a tin oxide (hereinafter referred to as Sn oxide), or a zinc oxide (hereinafter referred to as Zn oxide). It is preferable that it is an inorganic material containing any one. In oxides, Sn oxides, and Zn oxides are materials that can be easily formed by sputtering, and are materials that can provide good transparency and electrical conductivity. Particularly preferable materials are InSnO, GaZnO, SnO, In ₂ O ₃ and ZnO.

As the counter electrode 2, a transparent conductive film such as ITO, FTO, or zinc oxide, a conductive metal film such as zinc or platinum, or carbon is used. The counter electrode 2 is also generally formed on the substrate. The counter electrode substrate is also preferably glass or plastic film.
When a metal plate such as zinc is used as the counter electrode 2, the counter electrode 2 also serves as a substrate.
Furthermore, when the material of the counter electrode 2 includes a material that causes a reverse reaction opposite to the oxidation-reduction reaction caused by the electrochromic composition of the display layer 4, stable color development and decoloration is possible. That is, when the electrochromic composition is colored by oxidation, a reduction reaction is caused. When the electrochromic composition is colored by reduction, a material that causes an oxidation reaction is used as the counter electrode 2. The reaction of color development / decoloration in 4 becomes more stable.

As the electrolyte 3, generally, a support salt dissolved in a solvent is used.
As the supporting salt, for example, inorganic ion salts such as alkali metal salts and alkaline earth metal salts, quaternary ammonium salts, acids, and alkali supporting salts can be used. Specifically, LiClO ₄ , LiBF ₄ , LiAsF ₆ , LiPF ₆ , CF ₃ SO ₃ Li, CF ₃ COOLi, KCl, NaClO ₃ , NaCl, NaBF ₄ , NaSCN, KBF ₄ , Mg (ClO ₄ ) ₂ , Mg ( BF ₄ ) ₂ or the like can be used.
Examples of the solvent include propylene carbonate, acetonitrile, γ-butyrolactone, ethylene carbonate, sulfolane, dioxolane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, 1,2-dimethoxyethane, 1,2-ethoxymethoxyethane, and polyethylene glycol. , Alcohols, and the like are used.
In addition, since it is not particularly limited to a liquid electrolyte in which a supporting salt is dissolved in a solvent, a gel electrolyte or a solid electrolyte such as a polymer electrolyte is also used. For example, there are solid systems such as perfluorosulfonic acid polymer membranes. The solution system has an advantage of high ionic conductivity, and the solid system is suitable for producing a highly durable element without deterioration.

  When the display element of the present invention is used as a reflective display element, it is desirable to provide a white reflective layer 6 between the display electrode 1 and the counter electrode 2 as shown in FIG. For the white reflective layer 6, the simplest production method is to disperse white pigment fine particles in a resin and apply it on the counter electrode 2. As the white pigment fine particles, particles made of a general metal oxide can be applied, and specific examples include titanium oxide, aluminum oxide, zinc oxide, silicon oxide, cesium oxide, yttrium oxide and the like. Moreover, it can also serve as a white reflective layer by mixing white pigment particles in the polymer electrolyte.

  As a driving method of the display elements 10, 20, and 30, any method may be used as long as an arbitrary voltage and current can be applied. If a passive driving method is used, an inexpensive display element can be manufactured. Further, if the active driving method is used, high-definition and high-speed display can be performed. Active driving can be easily performed by providing an active driving element on the counter substrate.

  Hereinafter, the electrochromic compound and the electrochromic composition of the present invention, and a display device using them will be described in Examples.

Example 1
(A) Synthesis of Intermediate 8 of Structural Formula 8 In a reaction flask purged with nitrogen, 2.2 g of 4-vinylpyridine, 2.4 g of m-dibromobenzene, 0.18 g of palladium acetate, tri-o-tolylphosphine 0. 49 g, 4.0 g of triethylamine, and 10 ml of acetonitrile were charged, and the mixture was stirred at 80 ° C. for 12 hours. After allowing to cool, the reaction mixture was diluted with chloroform, insolubles were filtered off, the chloroform solution was washed with water, dried over anhydrous sodium sulfate, and then chloroform was distilled off. The obtained solid was purified by silica gel column chromatography using toluene / acetone (volume ratio; 1/1) as an eluent to obtain 2.2 g of Intermediate 8. When GC / MS of this product was measured, the molecular ion peak was M = 283.
The synthesis flow of this intermediate 8 is shown below.

(B) Formation of display electrode and electrochromic display layer Titanium oxide nanoparticle dispersion (SP210 manufactured by Showa Titanium Co., Ltd.) is applied to a part of a 30 mm × 30 mm glass substrate with FTO by spin coating, and 15 at 120 ° C. A titanium oxide particle film was formed by performing an annealing treatment for a minute. The thickness of the titanium oxide film was about 1.5 μm.
Next, a 0.2 wt% toluene solution of 3-bromopropyltrichlorosilane was prepared, and the glass substrate with FTO coated with the titanium oxide film was immersed for 30 minutes to bond 3-bromopropylsilane to the titanium oxide film surface. .
Thereafter, a 1 wt% toluene solution of the intermediate 8 synthesized in (A) is prepared, the substrate is immersed, and the intermediate 8 and 3-bromopropylsilane are reacted by refluxing at 120 ° C. for 2 hours. It was.

(C) Formation of counter electrode On the other hand, a 30 mm × 30 mm glass substrate is prepared, and an ITO film is formed on the entire upper surface by sputtering to have a thickness of about 150 nm. Formed. Further, spin a solution prepared by adding 25 wt% of 2-ethoxyethyl acetate to thermosetting conductive carbon ink (CH10 manufactured by Jujo Chemical Co., Ltd.) on the upper surface of a glass substrate on which a transparent conductive thin film is formed on the entire surface. The counter electrode was formed by applying by a coating method and performing an annealing treatment at 120 ° C. for 15 minutes.

(D) Production of electrochromic display device A display substrate and a counter substrate were bonded to each other through a 75 μm spacer to produce a cell. Next, 35 wt% of titanium oxide particles having a primary particle size of 300 nm (CR50 manufactured by Ishihara Sangyo Co., Ltd.) are dispersed in a solution in which tetrabutylammonium perchlorate is dissolved in dimethyl sulfoxide so as to be 20 wt% to prepare an electrolyte solution. And the electrochromic display element was produced by enclosing in a cell.

(E) Color development / decoloration test About the produced electrochromic display element, evaluation of color development / decoloration was implemented.
Evaluation of color development / decoloration was performed by irradiating diffused light using a spectrocolorimeter LCD-5000 manufactured by Otsuka Electronics Co., Ltd. When a negative electrode was connected to the display electrode 1 of the display element, a positive electrode was connected to the counter electrode 2, and a voltage of 3.0 V was applied for 1 second, the display element colored yellow. Furthermore, when a reverse voltage of -2.0 V was applied for 1 second, the color disappeared completely and returned to white. The reflection spectrum at the time of color development is shown in FIG. FIG. 5 shows the result of CIE color system coordinate conversion of this spectrum. From FIG. 4 and FIG. 5, it was confirmed that clear yellow color development was shown.

Place a display electrode with an electrochromic display layer in a quartz cell, use a platinum electrode as a counter electrode, an Ag / Ag + electrode (RE-7) as a reference electrode, and add tetrabutylammonium perchlorate to dimethyl The inside of the cell was filled with an electrolytic solution dissolved in sulfoxide to 20 wt%. The quartz cell was irradiated with deuterium tungsten halogen light (Ocean Optics DH-2000), the transmitted light was detected with a spectrometer (Ocean Optics USB4000), and the absorption spectrum was measured.
When a voltage of -1.5 V was applied using a potentiostat (ALS-660C, BAS Inc.), yellow color was developed. Absorption spectra before and after voltage application are shown in FIG.

(Example 2)
(A) Synthesis of Intermediate 14 of Structural Formula 14 In a reaction flask substituted with nitrogen, 1.8 g of 4-vinylpyridine, 1.6 g of 1,3,5-tribromobenzene, 0.13 g of palladium acetate, tri-o -Tolylphosphine (0.36 g), triethylamine (3.0 g) and acetonitrile (5 ml) were charged, and the mixture was stirred at 80 ° C for 12 hours. After allowing to cool, the reaction mixture was diluted with chloroform, insolubles were filtered off, the chloroform solution was washed with water, dried over anhydrous sodium sulfate, and then chloroform was distilled off. The obtained solid was purified by silica gel column chromatography using chloroform / ethanol (volume ratio; 20/1) as an eluent to obtain 0.75 g of intermediate 14. When the LC / MS of this product was measured, the molecular ion peak was M = 388.

(B) Production of Display Electrode and Electrochromic Display Layer, Counter Electrode, Electrochromic Display Device Using the intermediate 14 synthesized in (A), the display electrode, electrochromic display layer, and counter electrode are produced in the same manner as in Example 1. An electrode and an electrochromic display device were produced.

(C) Color development / decoloration test The produced electrochromic display element was evaluated for color development / decoloration in the same manner as in Example 1.
When a negative electrode was connected to the display electrode of the display element, a positive electrode was connected to the counter electrode, and a voltage of 2.5 V was applied for 1 second, the display element colored yellow. Further, when a reverse voltage of -3.0 V was applied for 1 second, the color was completely erased and returned to white. The reflection spectrum at the time of color development is shown in FIG. FIG. 8 shows the result of CIE color system coordinate conversion of this spectrum. From FIG. 7 and FIG. 8, it was confirmed that clear yellow color development was shown.

Further, the absorption spectrum was measured in the same manner as in Example 1.
When a voltage of -1.5 V was applied using a potentiostat (ALS-660C, BAS Inc.), yellow color was developed. Absorption spectra before and after voltage application are shown in FIG.

(Example 3)
(A) Synthesis of Intermediate 11 of Structural Formula 11 In a reaction flask substituted with nitrogen, 0.84 g of 4-vinylpyridine, 1.2 g of 3,5-dibromotrimethylsilylbenzene, 0.07 g of palladium acetate, tri-o-tolyl 0.19 g of phosphine, 0.89 g of triethylamine, and 20 ml of acetonitrile were charged, and the mixture was stirred at 80 ° C. for 12 hours. After allowing to cool, the reaction mixture was diluted with chloroform, insolubles were filtered off, the chloroform solution was washed with water, dried over anhydrous sodium sulfate, and then chloroform was distilled off. The obtained solid was purified by silica gel column chromatography using toluene / acetone (volume ratio; 1/1) as an eluent to obtain 0.89 g of intermediate 11. When GC / MS of this product was measured, the molecular ion peak was M = 356.

(B) Production of display electrode, electrochromic display layer, counter electrode, and electrochromic display device Using the intermediate 11 synthesized in (A), the display electrode, the electrochromic display layer, and the counter electrode were formed in the same manner as in Example 1. An electrode and an electrochromic display device were produced.

(C) Color development / decoloration test The produced electrochromic display element was evaluated for color development / decoloration in the same manner as in Example 1.
When the negative electrode was connected to the display electrode of the display element, the positive electrode was connected to the counter electrode, and a voltage of 2.7 V was applied for 2 seconds, the display element developed yellow. Further, when a reverse voltage of -2.0 V was applied for 1 second, the color was completely erased and returned to white.

Example 4
(A) Synthesis of Structural Formula 7 0.2 g of Intermediate 8 synthesized in Example 1, 1.0 g of diethyl bromoethylphosphonate, 3 ml of 1-propanol and 6 ml of water were charged, and this mixture was stirred at 90 ° C. for 40 hours. Stir. After allowing to cool, the reaction mixture was discharged into a mixed solution of 15 ml of water and 30 ml of ethyl acetate, and the aqueous layer was separated. This aqueous layer was charged into a reaction flask, 10 ml of concentrated hydrochloric acid was added thereto, and the mixture was stirred at 90 ° C. for 23 hours. After allowing to cool, water was distilled off from the reaction mixture under reduced pressure, the tar-like residue was dissolved in methanol, and this methanol solution was added dropwise to 2-propanol / ethanol (volume ratio; 2/1) with stirring. The product crystallized. This was collected by filtration, washed with 2-propanol and dried to obtain 0.15 g of structural formula 7.

(B) Production of display electrode, electrochromic display layer, counter electrode, and electrochromic display device Spin coating method using titanium oxide nanoparticle dispersion (SP210, Showa Titanium Co., Ltd.) on a part of 30 mm × 30 mm glass substrate with FTO And a titanium oxide particle film was formed by annealing at 120 ° C. for 15 minutes. The thickness of the titanium oxide film was about 1.5 μm.
Next, a 5 mM aqueous solution of structural formula 7 was prepared, the glass substrate with FTO coated with the titanium oxide film was immersed for 30 minutes, and the electrochromic compound of structural formula 4 was adsorbed on the titanium oxide film surface to produce a display electrode. .
Further, a counter electrode and an electrochromic display device were produced in the same manner as in Example 1.

(C) Color development / decoloration test The produced electrochromic display element was evaluated for color development / decoloration in the same manner as in Example 1.
When the negative electrode was connected to the display electrode of the display element, the positive electrode was connected to the counter electrode, and a voltage of 3.0 V was applied for 1 second, the display element colored yellow. Further, when a reverse voltage of -2.0 V was applied for 1 second, the color was completely erased and returned to white.

(Example 5)
The intermediate 8 synthesized in Example 1 was reacted with two equivalents of ethyl bromide to synthesize structural formula 5. Next, a water / 2,2,3,3-tetrafluoropropanol (10 wt%) solution was prepared, and 1 wt% of the structural formula 5 was dissolved to obtain an electrochromic compound solution. 50 wt% of the electrochromic compound solution is added to an electrolytic solution in which tetrabutylammonium perchlorate is dissolved in dimethyl sulfoxide to 20 wt%, and a glass substrate with a 30 mm × 30 mm SnO ₂ conductive film (AGC Fabrictech) Was sealed in a cell bonded with a display substrate and a counter substrate through a 75 μm spacer to produce an electrochromic display element 10.
When a voltage of 3.0 V was applied to the prepared display element for 2 seconds, the display element was colored yellow. Further, when a reverse voltage of -1.5 V was applied for 2 seconds, it completely disappeared and returned to transparency.

(Example 6)
(A) Synthesis of structural formula 17 In a 50 ml flask, 4-vinylpyridine 2.2 g, 1,4-dibromobenzene 2.4 g, palladium acetate 0.18 g, tri-o-tolylphosphine 0.49 g, triethylamine 4.0 g, 10 ml of acetonitrile was added and the system was purged with nitrogen. When the temperature was raised to 75 ° C. and reacted overnight, crystals were precipitated. The precipitate was filtered and washed with acetonitrile. The obtained crystals were dissolved in chloroform, filtered with radiolite added, and the filtrate was concentrated to obtain 4.4 g of crude crystals. The crude crystals were dissolved in methanol / water, filtered, and washed with hot water. Further, the product was refined with hot acetonitrile to obtain 2.2 g of Intermediate 17 which was a pale yellow crystal.
When GC / MS of this compound was measured, the molecular ion peak was M = 284.
The synthesis flow of this intermediate 17 is shown below.

  0.2 g of Intermediate 17, 1.0 g of diethyl bromoethylphosphonate, 3 ml of 1-propanol, and 6 ml of water were charged, and the mixture was stirred at 90 ° C. for 45 hours. After allowing to cool, the reaction mixture was discharged into a mixed solution of 15 ml of water and 30 ml of ethyl acetate, and the aqueous layer was separated. This aqueous layer was charged into a reaction flask, 10 ml of concentrated hydrochloric acid was added thereto, and the mixture was stirred at 90 ° C. for 30 hours. After allowing to cool, water was distilled off from the reaction mixture under reduced pressure, the tar-like residue was dissolved in methanol, and this methanol solution was added dropwise to 2-propanol / ethanol (volume ratio; 2/1) with stirring. The product crystallized. This was collected by filtration, washed with 2-propanol and dried to obtain 0.15 g of the structural formula 17.

(B) Production of display electrode, electrochromic display layer, counter electrode, and electrochromic display device Display electrodes, electrochromic display layer, counter electrode, and electrochromic display device were produced in the same manner as in Example 4.

(C) Color development / decoloration test The produced electrochromic display element was evaluated for color development / decoloration in the same manner as in Example 1.
When a negative electrode was connected to the display electrode of the display element, a positive electrode was connected to the counter electrode, and a voltage of 3.0 V was applied for 1 second, the display element developed cyan. Further, when a reverse voltage of -3.0 V was applied for 1 second, the color disappeared and the color returned to light yellow.

(Example 7)
(A) Synthesis of Structural Formula 25 50 ml Three-necked reactor was charged with 1.8 g of bisbromomethyldurene and 2.1 g of triethyl phosphite and heated and stirred at 110 to 120 ° C. The reaction was carried out at this temperature for 1 hour. Upon cooling to room temperature, a solid precipitated. Hexane was added and filtered. The obtained crystal was dried to obtain 2.0 g of 2,3,5,6 tetramethyl-1,4-bis (diethylphosphonylmethyl) benzene.
A 50 ml three-necked reactor was charged with 0.87 g of 2,3,5,6 tetramethyl-1,4-bis (diethylphosphonylmethyl) benzene, 20 ml of DMF (dehydrated), and 0.47 g of 4-formylpyridine. After nitrogen substitution, when a solution of 0.56 g of potassium t-butoxide in 10 ml DMF was slowly added dropwise, the solution turned into a blue-green solution. The reaction was carried out at 30-40 ° C. for 2 hours. The reaction solution was discharged into water, and sodium chloride was added to precipitate a solid. The precipitated solid was filtered out and dried to obtain 0.40 g of a crude product. The crude product was purified by a silica gel column (toluene / acetone 3/1 → 1/1) to obtain 0.30 g of intermediate 25. When GC / MS of this compound was measured, the molecular ion peak was M = 340.
The synthesis flow of this intermediate 25 is shown below.

  0.2 g of Intermediate 25, 1.0 g of diethyl bromoethylphosphonate, 3 ml of 1-propanol, and 6 ml of water were charged, and the mixture was stirred at 90 ° C. for 35 hours. After allowing to cool, the reaction mixture was discharged into a mixed solution of 15 ml of water and 30 ml of ethyl acetate, and the aqueous layer was separated. This aqueous layer was charged into a reaction flask, 10 ml of concentrated hydrochloric acid was added thereto, and the mixture was stirred at 90 ° C. for 20 hours. After allowing to cool, water was distilled off from the reaction mixture under reduced pressure, the tar-like residue was dissolved in methanol, and this methanol solution was added dropwise to 2-propanol / ethanol (volume ratio; 2/1) with stirring. The product crystallized. This was collected by filtration, washed with 2-propanol and dried to obtain 0.19 g of the structural formula 25.

(B) Production of display electrode, electrochromic display layer, counter electrode, and electrochromic display device Display electrodes, electrochromic display layer, counter electrode, and electrochromic display device were produced in the same manner as in Example 4.

(C) Color development / decoloration test The produced electrochromic display element was evaluated for color development / decoloration in the same manner as in Example 1.
When a negative electrode was connected to the display electrode of the display element, a positive electrode was connected to the counter electrode, and a voltage of 3.0 V was applied for 1 second, the display element developed cyan. Furthermore, when a reverse voltage of -3.0 V was applied for 1 second, the color disappeared and the color returned to white. The reflection spectrum at the time of color development is shown in FIG. FIG. 11 shows the result of CIE color system coordinate conversion of this spectrum. It was confirmed from FIGS. 10 and 11 that clear cyan coloration was exhibited.
Place a display electrode with an electrochromic display layer in a quartz cell, use a platinum electrode as a counter electrode, an Ag / Ag + electrode (RE-7) as a reference electrode, and add tetrabutylammonium perchlorate to dimethyl The inside of the cell was filled with an electrolytic solution dissolved in sulfoxide to 20 wt%. The quartz cell was irradiated with deuterium tungsten halogen light (Ocean Optics DH-2000), the transmitted light was detected with a spectrometer (Ocean Optics USB4000), and the absorption spectrum was measured.
When a voltage of -1.5 V was applied using a potentiostat (ALS-660C, BAS Co., Ltd.), cyan color was developed. Absorption spectra before and after voltage application are shown in FIG.

(Example 8)
(A) Synthesis of Structural Formula 29 100 ml Four-necked reactor was charged with 2,3,5,6-tetrafluoro-p-xylene 3.6 g, carbon tetrachloride 30 ml, NBS 7.1 g, AIBN 0.10 g 70 The reaction was carried out at 17 ° C. for 17 hours. After completion of the reaction, it was allowed to cool to room temperature. 10 g of activated clay was added and stirred for treatment. The reaction solution was filtered, and the residue was washed well with hexane. The filtrate was concentrated to give a crude product as crystals. This crude product was dissolved in methanol and purified to obtain 3.8 g of 2,3,5,6-tetrafluoro-1,4-bisbromomethylbenzene.
A 50 ml three-necked reactor was charged with 2,3,5,6-tetrafluoro-1,4-bisbromomethylbenzene (2.0 g) and triethyl phosphite (2.2 g) and heated to 110-120 ° C. with stirring. The reaction was carried out at this temperature for 2 hours. Upon cooling to room temperature, a solid precipitated. Hexane was added and filtered. The obtained crystal was dried to obtain 2.4 g of 2,3,5,6-tetrafluoro-1,4-bis (diethylphosphonylmethyl) benzene.
A 50 ml three-necked reactor was charged with 2.3 g of 2,3,5,6-tetrafluoro-1,4-bis (diethylphosphonylmethyl) benzene, 20 ml of DMF (dehydrated), and 1.2 g of 4-formylpyridine. . After nitrogen substitution, when a 10 ml DMF solution of 1.4 g of potassium t-butoxide was slowly added dropwise, the solution turned into a red solution. The reaction was allowed to proceed for 18 hours at room temperature. The reaction solution was discharged into water and extracted with chloroform. The reaction solution was concentrated to obtain 0.97 g of a crude product. The crude product was purified with a silica gel column (toluene / acetone 1/1), and the resulting solid was purified with methanol to obtain 0.69 g of the desired product.
When GC / MS of this compound was measured, the molecular ion peak was M = 356.
The synthesis flow of this intermediate 29 is shown below.

  0.2 g of Intermediate 29, 1.0 g of diethyl bromoethylphosphonate, 3 ml of 1-propanol, and 6 ml of water were charged, and the mixture was stirred at 90 ° C. for 37 hours. After allowing to cool, the reaction mixture was discharged into a mixed solution of 15 ml of water and 30 ml of ethyl acetate, and the aqueous layer was separated. This aqueous layer was charged into a reaction flask, 10 ml of concentrated hydrochloric acid was added thereto, and the mixture was stirred at 90 ° C. for 22 hours. After allowing to cool, water was distilled off from the reaction mixture under reduced pressure, the tar-like residue was dissolved in methanol, and this methanol solution was added dropwise to 2-propanol / ethanol (volume ratio; 2/1) with stirring. The product crystallized. This was collected by filtration, washed with 2-propanol and dried to obtain 0.14 g of the structural formula 29.

(B) Production of Display Electrode, Electrochromic Display Layer, Counter Electrode, and Electrochromic Display Device Using the intermediate 29 synthesized in (A), the display electrode, the electrochromic display layer, and the counter electrode in the same manner as in Example 1. An electrode and an electrochromic display device were produced.

(C) Color development / decoloration test The produced electrochromic display element was evaluated for color development / decoloration in the same manner as in Example 1.
When a negative electrode was connected to the display electrode of the display element, a positive electrode was connected to the counter electrode, and a voltage of 3.0 V was applied for 1 second, the display element developed cyan. Furthermore, when a reverse voltage of -3.0 V was applied for 1 second, the color disappeared and the color returned to white.

Example 9
(A) Synthesis of structural formula 45 A 100 ml four-necked reactor was charged with 2.3 g of 2,5-dimethylterephthalonitrile, 23 ml of carbon tetrachloride, 5.3 g of NBS, and 0.07 g of AIBN, and reacted at 75 ° C. for 1 hour. It was. After completion of the reaction, it was allowed to cool to room temperature. The reaction solution was filtered and the residue was washed well with carbon tetrachloride. The filtrate was concentrated to give a crude product as an oil. The crude product was crystallized by adding methanol. The crystals were filtered out to obtain 0.57 g of 1,4-dicyano-2,5-bisbromomethylbenzene.
A 50 ml three-necked reactor was charged with 0.55 g of 1,4-dicyano-2,5-bisbromomethylbenzene and 0.61 g of triethyl phosphite and heated to 100-110 ° C. with stirring. The reaction was carried out at this temperature for 2 hours. The mixture was allowed to cool to room temperature and purified with a silica gel column to obtain 0.45 g of 2,5-dicyano-1,4bis (diethylphosphonylmethyl) benzene.
A 50 ml three-necked reactor was charged with 0.45 g of 2,5-dicyano-1,4-bis (diethylphosphonylmethyl) benzene, 15 ml of DMF (dehydrated), and 0.28 g of 4-formylpyridine. After substituting with nitrogen, a solution of 0.35 g of potassium t-butoxide in 5 ml of DMF was slowly added dropwise to give a greenish brown solution. The reaction was carried out at 60 ° C. for 3 hours. The reaction solution was discharged into water and extracted with chloroform. The reaction solution was concentrated to obtain a crude product. The crude product was purified with a silica gel column (toluene / acetone 1/1) and the resulting solid was purified with methanol to obtain 0.08 g of intermediate 45.
The synthesis flow of this intermediate 45 is shown below.

(B) Production of Display Electrode, Electrochromic Display Layer, Counter Electrode, Electrochromic Display Device Using the intermediate 45 synthesized in (A), the display electrode, the electrochromic display layer, and the counter electrode in the same manner as in Example 1. An electrode and an electrochromic display device were produced.

(C) Color development / decoloration test The produced electrochromic display element was evaluated for color development / decoloration in the same manner as in Example 1.
When the negative electrode was connected to the display electrode of the display element, the positive electrode was connected to the counter electrode, and a voltage of 3.0 V was applied for 1 second, the display element developed black. Furthermore, when a reverse voltage of -3.0 V was applied for 1 second, the color disappeared and the color returned to white. The reflection spectrum at the time of color development is shown in FIG. FIG. 14 shows the result of CIE color system coordinate conversion of this spectrum. From FIG. 13 and FIG. 14, it was confirmed that clear black color development was shown.
Place a display electrode with an electrochromic display layer in a quartz cell, use a platinum electrode as a counter electrode, an Ag / Ag + electrode (RE-7) as a reference electrode, and add tetrabutylammonium perchlorate to dimethyl The inside of the cell was filled with an electrolytic solution dissolved in sulfoxide to 20 wt%. The quartz cell was irradiated with deuterium tungsten halogen light (Ocean Optics DH-2000), the transmitted light was detected with a spectrometer (Ocean Optics USB4000), and the absorption spectrum was measured.
When a voltage of -1.5 V was applied using a potentiostat (ALS-660C, BAS Co., Ltd.), black color was developed. The absorption spectra before and after voltage application are shown in FIG.

(Comparative Example 1)
In Example 1, the compound used is replaced with a viologen compound represented by the following structural formula (59), which is a known electrochromic compound, and other than that, a display device of a comparative example is produced in the same manner as in Example 1, and the same. Evaluated.

When a negative electrode was connected to the display electrode 1 of the display element, a positive electrode was connected to the counter electrode 2, and a voltage of 3.0 V was applied for 1 second, the display element was colored blue. Furthermore, when a reverse voltage of −4.5 V was applied for 2 seconds, the color was completely erased and returned to white.
In addition, FIG. 16 shows a reflection spectrum of the display element of Comparative Example 1 in a colored state. As is apparent from the spectrum, Comparative Example 1 in FIG. 16 has a wide region width where the reflectance is low in the visible region, and the light absorption is broad. The result is a blue color.

DESCRIPTION OF SYMBOLS 1 Display electrode 2 Counter electrode 3 Electrolyte 4a, 4b Display layer 5a Organic electrochromic compound 5b Redox color development part 5c Adsorption group (bonding group)
5d Spacer part 5e Organic electrochromic composition 6 White reflective layer 10, 20, 30 Display element

JP 2003-161964 A JP 2004-361514 A Japanese translation of PCT publication No. 2004-520621 Special table 2004-536344 gazette Special table 2001-510590 gazette JP 2003-121883 A JP 2006-106669 A JP 2003-270671 A JP 2004-151265 A JP 2008-122578 A

Claims (7)

The electrochromic compound represented by following General formula (1).
(In the general formula (1), X ₁ , X ₂ , X ₃ and X ₄ each independently represent a hydrogen atom or a monovalent substituent, R independently represents a monovalent substituent, and n represents 1 represents an integer of 1 to 6, Ar represents a benzene ring which may have a substituent when n is 1 to 5, and simply represents a benzene ring when n is 6, and A ⁻ represents a monovalent anion. Represents.) The electrochromic compound according to claim 1, comprising a structure represented by the following general formula (2).
(In the general formula (2), X ₁ , X ₂ , X ₃ , X ₄ , X ₅ , X ₆ , X ₇ , X ₈ , Y ₁ , Y ₂ , Y ₃ , Y ₄ are each independently a hydrogen atom. Alternatively, it represents a monovalent substituent, R ₁ and R ₂ each independently represent a monovalent substituent, and A ⁻ represents a monovalent anion.) The electrochromic compound according to claim 1, comprising a structure represented by the following general formula (3).
(In the general formula (3), X ₁ , X ₂ , X ₃ , X ₄ , X ₅ , X ₆ , X ₇ , X ₈ , Y ₁ , Y ₂ , Y ₃ , Y ₄ are each independently a hydrogen atom. Alternatively, it represents a monovalent substituent, R ₁ and R ₂ each independently represent a monovalent substituent, and A ⁻ represents a monovalent anion.) The electrochromic compound according to claim 3, comprising a structure represented by the following general formula (4).
(In the general formula (4), X ₁ , X ₂ , X ₃ , X ₄ , X ₅ , X ₆ , X ₇ , X ₈ , Y ₁ , Y ₂ are each independently a hydrogen atom or a monovalent substituent. R ₁ and R ₂ each independently represents a monovalent substituent, and A ⁻ represents a monovalent anion.) 2. At least one of the R or at least one of the R ₁ and R ₂ is a functional group capable of directly or indirectly binding to a hydroxyl group. The electrochromic compound of -4.   An electrochromic composition comprising a conductive or semiconducting nanostructure and the electrochromic compound according to claim 5 bonded or adsorbed to the nanostructure. A display electrode, a counter electrode provided to be spaced apart from the display electrode, and an electrolyte disposed between the display electrode and the counter electrode,
A display layer on a surface of the display electrode facing the counter electrode;
The display layer comprises at least the electrochromic compound according to any one of claims 1 to 5 or the electrochromic composition according to claim 6.