JP2007304389A - Electrochromic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an elctrochromic device with which extremely clear coloring is performed, formation of a sharp image is attainable, and full-coloration is satisfactory. <P>SOLUTION: The elctrochromic device 10 is arranged with a display electrode 11 including a transparent electrode 1, and with a counter electrode 12 via an electrolytic layer 13, and is formed with a polymer film electrode 2 consisting of a polyquinone compound composed of any one of benzoquinone, napththoquinone, and anthraquinone, as a monomer on the transparent electrode 1 constituting the display electrode 11. An organic coloring material having the nature to color and decolor according to a pH change is formed or deposited on the polymer film electrode 2 or in the polymer film, and by applying a voltage between the display electrode 11 and the counter electrode 12, the organic coloring material is reversibly colored and decolored. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrochromic device excellent in display color purity, capable of forming a clear and sharp image, and excellent in repeated durability.

In recent years, there has been a growing demand for display dye materials and display elements using the same that are bright and excellent in color purity, consume less power, and can be easily applied to full-color display. Conventionally, CRT, LCD, PDP There have been proposals for technologies related to light emitting elements such as ELD.
However, since the various light-emitting elements are used in such a way that the user looks directly at the light emission, there is a problem that visual fatigue occurs when viewed for a long time.
In addition, mobile devices such as mobile phones are often used outdoors, and there is also a problem that the visibility is deteriorated by canceling light emission under sunlight.
Furthermore, LCD is a technology that is especially in demand among light-emitting elements, and is used in various display applications such as large and small. However, LCD has a narrow viewing angle and is easy to see. Compared to other light emitting elements, it has a problem to be improved.

By the way, regarding the reflective display element, various technologies have been proposed due to an increase in demand for electronic paper.
For example, a reflective LCD or an electrophoretic method can be used.
Conventionally, as the reflective LCD, a GH type liquid crystal system using a dichroic dye, a cholesteric liquid crystal, and the like are known. These methods have the advantage of lower power consumption because they do not use a backlight compared to conventional light emitting LCDs, but they have a viewing angle dependency and low light reflection efficiency. There is a problem that the screen will inevitably become dark.
On the other hand, the electrophoresis method is a method that utilizes a phenomenon in which charged particles dispersed in a solvent move by an electric field, and has the advantage of low power consumption and no viewing angle dependency. However, in the case of performing full color, it is necessary to apply a juxtaposed mixing method using a color filter, so that there is a problem that the reflectance is lowered and the screen is inevitably darkened.

Conventionally, an electrochromic (hereinafter abbreviated as EC) element is used for a light control mirror of an automobile, a timepiece or the like.
The display using this EC element does not require a polarizing plate, has no viewing angle dependency, is a color-forming type, has excellent visibility, has a simple structure and can be easily enlarged, and has various color tones depending on the choice of materials. The display has the advantage that it can be displayed.

In recent years, as a display device using an EC element, there has been proposed a display device having a structure in which a semiconductor nanoporous layer is provided on at least one of a pair of transparent electrodes and an EC dye is supported on the semiconductor nanoporous layer. (For example, refer to Patent Documents 1 and 2.)
Since this display device can form an open circuit and can stop the display state only by blocking the movement of electrons between the electrodes and maintaining the oxidation-reduction state, power for maintaining the display image is unnecessary, and power consumption is extremely high. It is particularly excellent in that it is low.

JP 2003-248242 A JP 2003-270670 A

However, in the techniques described in the above-mentioned conventional publicly known documents, a bipyridine compound called viologen is used as a reactive dye. It is not assumed to perform full color display.
In addition, those that develop color in a monovalent or divalent radical state as typified by bipyridine compounds have structurally complicated electronic transitions, a broad absorption wavelength width in the color development spectrum, and a strict hue. It is extremely difficult to control.
In particular, when displaying a full-color image, an EC dye having steep mono-peak absorption for developing the three primary colors of cyan (C), magenta (M), and yellow (Y) is preferable. The bipyridine compound used is not suitable for full color display for the reasons described above.

As other dyes than the bipyridine compound, organic dyes having absorption in the visible region in a steady state such as cyanine, styryl, and triphenylmethane dyes are known. These dyes are excellent in that they have a monopeak with a steep absorption wavelength and have a high molar extinction coefficient, so that hue control is easy.
However, when these dye materials are oxidized or reduced to a decolored state, so-called neutral radical state, they become slightly yellow and difficult to be completely colorless, which is precise and clear. It has been a problem to display a full color image.

  Accordingly, in the present invention, in view of the technical problems of the conventional EC element as described above, an electrochromic device having a structure that can contribute to the formation of a clear and stable full-color image with a sharp color tone is proposed. It was.

  In the present invention, a display electrode having a transparent electrode and a counter electrode are disposed via an electrolyte layer, and a polyquinone having at least one of benzoquinone, naphthoquinone, and anthraquinone as a monomer on the transparent electrode. A polymer film electrode made of a compound is formed, and an organic dye having a property of developing and decoloring according to pH change is supported on or in the polymer film electrode, and is opposed to the display electrode. Provided is an electrochromic device adapted to reversibly color-decolor an organic dye by applying a voltage between electrodes.

  According to the present invention, a full color display capable of repeatedly displaying clear coloration many times by utilizing a color developing / decoloring reaction of an organic dye due to a change in proton concentration based on a redox of a polyquinone compound constituting a polymer film electrode. An electrochromic device suitable for image formation was obtained.

Hereinafter, the electrochromic device of the present invention and a display method using the same will be specifically described with reference to the drawings.
However, the present invention is not limited to the following examples, and a conventionally known configuration can be added as appropriate, and does not depart from the gist of the present invention.

FIG. 1 shows a schematic configuration diagram of an example of the electrochromic device of the present invention.
In the electrochromic device 10, a display electrode 11 and a counter electrode 12 are arranged via an electrolyte layer 13.
The display electrode 11 has a polymer film electrode 2 formed on the transparent electrode 1, and the organic dye 3 having a color-decoloring property according to pH change is carried on the polymer film electrode 2 or in the polymer film electrode. It has the structure which was made.
In the example of FIG. 1, one having two display electrode configurations is connected through a connection portion 14 to form one display electrode 11. By adopting a configuration in which a plurality of layers are stacked in this manner, the surface area of the entire display electrode is increased, and the display color density of the entire device can be increased.
In this example, the display electrode has a two-layer structure, but the present invention is not limited to this example and can be appropriately increased or decreased depending on the organic dye material.
Hereinafter, the components will be sequentially described.

The transparent electrode 1 has a configuration in which a transparent electrode layer is laminated on a predetermined transparent substrate.
The transparent substrate is preferably a material having excellent heat resistance and high dimensional stability in the planar direction. Specifically, a glass material and a transparent resin can be applied, but the material is not limited thereto.
Examples of the transparent resin include polyethylene terephthalate, polyethylene naphthalate, polyamide, polysulfone, polyether sulfone, polyether ether ketone, polyphenylene sulfide, polycarbonate, polyimide, polymethyl methacrylate, and polystyrene.
Examples of the material for forming the transparent electrode layer include a mixture of In ₂ O ₃ and SnO ₂ , a so-called ITO film, and a film coated with SnO ₂ or In ₂ O ₃ .
Further, Sn, Sb, F, or the like may be doped into the ITO film or a film coated with SnO ₂ or In ₂ O ₃ , and other MgO, ZnO, or the like can be applied.

In order to perform high-density color display, it is advantageous that the display electrode 11 has a larger surface area. Therefore, a porous electrode may be formed on the transparent electrode 1 to provide fine irregularities on the surface. .
The porous electrode can be formed of, for example, a metal, an intrinsic semiconductor, an oxide semiconductor, a composite oxide semiconductor, an organic semiconductor, carbon, or the like.
Examples of the metal include Au, Ag, Pt, and Cu. Examples of the intrinsic semiconductor include Si, Ge, and Te.
Examples of the oxide semiconductor include TiO ₂ , SnO ₂ , Fe ₂ O ₃ , SrTiO ₃ , WO ₃ , ZnO, ZrO ₂ , Ta ₂ O ₅ , Nb ₂ O ₅ , V ₂ O ₅ , In ₂ O ₃ , Examples thereof include CdO, MnO, CoO, TiSrO ₃ , KTiO ₃ , Cu ₂ O, sodium titanate, barium titanate, and potassium niobate.
Examples of the complex oxide semiconductor include SnO ₂ —ZnO, Nb ₂ O ₅ —SrTiO ₃ , Nb ₂ O ₅ —Ta ₂ O ₅ , Nb ₂ O ₅ —ZrO ₂ , Nb ₂ O ₅ —TiO _{2. , Ti-SnO 2, Zr-} SnO 2, Sb-SnO 2, Bi-SnO 2, In-SnO 2 and the like. In _{particular, TiO 2, SnO 2, Sb} -SnO 2, In-SnO 2 are preferred.
Examples of the organic semiconductor include polythiophene, polypyrrole, polyacetylene, polyphenylene vinylene, and polyphenylene sulfide.
As the porous electrode, those having a porous shape, a lot shape, a wire shape and the like having fine pores on the surface and inside are suitable.

Next, the polymer film electrode 2 will be described.
The polymer film electrode 2 is formed from a polyquinone compound having at least one of benzoquinone, naphthoquinone, and anthraquinone as a monomer. That is, it is a polymer composed of repeating units of a benzoquinone derivative, a naphthoquinone derivative, and an anthraquinone derivative.
Specific examples include polybenzoquinone (following formula (6)), polymercaptobenzoquinone (following formula (7)), poly (1,4-naphthoquinone-5,8-diyl) (following formula (8)), poly ( Anthraquinone-2,6-diyl) (following formula (9)), poly (anthraquinone-1.4-diyl) (following formula (10)), poly (2-methylanthraquinone-1,4-diyl) (following formula (11)). In the following formula, n is an integer for polymer formation.
In addition, in order to contribute to the proton concentration change mentioned later, the polymer film electrode 2 preferably has a configuration with a large surface area. For example, those having a porous shape, a lot shape, a wire shape or the like having fine pores on the surface and inside are suitable.

The polymer film electrode 2 is obtained by forming a film of a predetermined polyquinone compound. Specifically, it can be formed by an electrolytic polymerization method, a coating method such as dip, spin, or cast.
When forming by a coating method, a predetermined polyquinone compound is dissolved in an organic solvent and applied. Organic solvents include water, alcohol, acetonitrile, propionitrile, halogenated hydrocarbons, ethers, dimethyl sulfoxide, N, N-dimethylformamide, N-methylpyrrolidone, chloroform, dichloromethane, methylene chloride, toluene, tetrahydrofuran, ester , Carbonates, ketones, hydrocarbons and the like can be applied. These may be used singly or may be mixed as appropriate.
When the polymer film electrode 2 is formed on the transparent electrode 1 by the electrolytic polymerization method, the polyquinone film is formed by causing an oxidation reaction in an electrolytic solution in which at least one of benzoquinone, naphthoquinone, and anthraquinone is dissolved. Form. Examples of the quinone monomer include compounds represented by the following formulas (12) to (14).

The polymer film electrode 2 may be formed by coating a quinone compound that has been polymerized in advance.
In this case, polyquinone can be obtained by performing a polymerization reaction using a dihalogenated quinone monomer.
For example, the dihalogenated quinone monomer represented by the following formula (15) and the following formulas (16), (17), and (18) are reacted in a suitable solvent under a nitrogen atmosphere, and then an acid is added to the reaction solution. Is added to precipitate the polyquinone compound represented by the above formula (10).

Next, the organic dye 3 will be described.
The organic dye 3 may be formed as a film on the surface of the polymer film electrode 2 or may be carried inside the electrode.
The organic dye 3 applied in the present invention is a material that develops and decolors according to changes in pH.

  Examples of organic pigment materials that develop color in an alkaline environment are shown in the following formulas (19) to (23).

  Examples of organic pigment materials that develop color in an acidic environment are shown in the following formulas (24) to (28).

As a method for supporting the organic dye on the polymer film electrode 2, a conventionally known method such as a dipping method, a coating method such as spin, a method of casting simultaneously with polyquinone, a method of polymerizing by electrolytic polymerization, a vacuum deposition method, etc. is applied. it can.
Examples of the solvent for dissolving the organic dye include water, alcohol, acetonitrile, propionitrile, halogenated hydrocarbons, ethers, dimethyl sulfoxide, N, N-dimethylformamide, N-methylpyrrolidone, esters, and carbonates. , Ketones, hydrocarbons, etc. are applicable. These may be used singly or may be used in combination as appropriate.

In FIG. 1, in order to obtain a sufficient color density, the display electrode has a two-layer structure as shown in FIG. 1, but the amount and material of the organic dye supported on the polymer film electrode 2 are appropriately selected and adjusted. By doing so, the display electrode may be a single layer, or a plurality of layers may be further laminated.
When the display electrode has a multi-layer structure, a conventionally known plastic adhesive can be appropriately used for the connection portion 14.

The electrolyte layer 13 is obtained by dissolving a supporting electrolyte in a solvent.
Examples of the supporting electrolyte include lithium salts such as LiCl, LiBr, LiI, LiBF ₄ , LiClO ₄ , LiPF ₆ , and LiCF ₃ SO ₃ , potassium salts such as KCl, KI, and KBr, and NaCl, NaI, NaBr, and the like. And tetraalkylammonium salts such as tetraethylammonium borofluoride, tetraethylammonium perchlorate, tetrabutylammonium borofluoride, tetrabutylammonium perchlorate, and tetrabutylammonium halide.

A known redox compound may be added to the electrolyte layer 13 as necessary.
As the redox substance, for example, a ferrocene derivative, a tetracyanoquinodimethane derivative, a benzoquinone derivative, a phenylenediamine derivative, or the like can be applied.
As the solvent, a solvent that dissolves the supporting electrolyte and does not dissolve the organic dye described above is selected.
For example, it is appropriately selected from water, acetonitrile, dimethylformamide, propylene carbonate, dimethyl sulfoxide, propylene carbonate and the like.

A so-called matrix material may be applied to the electrolyte layer 13.
Matrix material can be appropriately selected depending on the purpose, for example, skeletal unit _{respectively, - (CC-O) n} -, - (CC (CH 3) -O) n -, - (CC-N ) _n- , or-(C-C-S) _n- , for example, polyethylene oxide, polypropylene oxide, polyethyleneimine, and polyethylene sulfide.
In addition, you may have a branched structure suitably by making these into a principal chain structure. Polymethyl methacrylate, polyvinylidene fluoride, polyvinylidene chloride, polycarbonate, and the like are also suitable.

The electrolyte layer 13 may be a polymer solid electrolyte layer.
In this case, it is preferable to add a predetermined plasticizer to the polymer of the matrix material.
As the plasticizer, when the matrix polymer is hydrophilic, water, ethyl alcohol, isopropyl alcohol, and a mixture thereof are preferable. When the matrix polymer is hydrophobic, propylene carbonate, dimethyl carbonate, ethylene carbonate, γ- Preferred are butyrolactone, acetonitrile, sulfolane, dimethoxyethane, ethyl alcohol, isopropyl alcohol, dimethylformamide, dimethyl sulfoxide, dimethylacetamide, n-methylpyrrolidone, and mixtures thereof.

A conventionally known electrode body can be applied to the counter electrode 12.
For example, a transparent electrode may be formed on a predetermined transparent substrate, or a metal electrode such as platinum may be applied.
In order to make the electrochromic device of the present invention color display and increase the visibility thereof, the counter electrode 12 is preferably transparent, and may be opaque when monochrome display is made monochrome.

The electrochromic device 10 of the present invention displays as follows.
A predetermined lead wire is connected to the pair of electrode structures 11 and 12 constituting the electrochromic device 10 to form a display device.
When a predetermined voltage is applied between the electrodes through a predetermined lead wire, electrons are transferred between the transparent electrode 1 and the polyquinone constituting the polymer film electrode 2 formed thereon, and the polyquinone takes in protons, It changes from keto type to enol type. As a result, the pH of the electrolyte layer in the vicinity of the electrode changes, and the organic dye material causes a color-decoloring reaction with the change in pH.
Since the pH value rises when polyquinone takes in protons, the alkali coloring type organic dyes of the above formulas (19) to (23) cause a coloring reaction, and the acid coloring type of the above formulas (24) to ( The organic dye of 28) causes a decoloring reaction.

The electrochromic device of the present invention is not limited to the configuration shown in FIG. 1, and can be applied to a device configuration capable of multicolor display.
That is, an electrode structure is produced by applying an organic dye that has the same structure as the electrochromic structure shown in FIG. 1 and colors yellow (Y), magenta (M), and cyan (C). By laminating, an electrochromic device with full color display can be obtained.

Specific examples of the electrochromic device of the present invention and comparative examples will be described.
A sample of the electrochromic device having the configuration shown in FIG. 1 is prepared.
First, a polyquinone compound for preparing the polymer film electrode 2 was synthesized as follows.

(Synthesis of polyquinone compound: compound represented by formula (7))

2.5 g of 5-hydroxy-1,3-benzoxathiol-2-one is dissolved in 25 ml of 2M aqueous sodium hydroxide solution under N ₂ gas atmosphere. The reaction is performed at 100 ° C. for 1 hour in an N ₂ gas atmosphere, and the reaction is cooled to room temperature. Subsequently, 2M sulfuric acid is added under a N ₂ gas atmosphere until carbon dioxide is produced. Next, diethyl ether is added and stirred to collect ether. This is repeated three times.
The ether solutions collected as described above were collected together, the solvent was removed, and then crystallized with a mixed solvent of chloroform / ethyl acetate = 10: 1 to obtain mercaptohydroquinone.

A polymercaptohydroquinone film is formed on the ITO electrode using the mercaptohydroquinone synthesized as described above.
First, as the transparent electrode 1, an ITO film formed on a transparent substrate was used.
As the counter electrode 12, electrolytic oxidation polymerization of mercaptohydroquinone was performed at a voltage of +0.7 V using a platinum wire and silver / silver chloride as a reference electrode.
At this time, as the electrolytic solution, a mixed solution of 50 ml of Britton-Robinson buffer (pH 7.0) and 10 ml of ethanol solution in which 0.09 g of mercaptohydroquinone was dissolved was used, and electrolytic oxidation polymerization was performed using 30 N ₂ gas. After deoxygenating by aeration for 30 minutes, it was carried out with stirring at room temperature for another 30 minutes.
Thereafter, a drying process and a methanol washing process were performed.
When CV measurement was performed using the quinone film-formed substrate prepared as described above, a clear redox wave could be observed, and the desired polyquinone film (mercaptohydroquinone) was formed on the transparent electrode 1. It has been confirmed.

(Synthesis of polyquinone compound: compound represented by formula (10))

Under an N ₂ gas atmosphere, 1.8 g of bis (1,5-cyclooctadiene) nickel (zero valence), 0.624 ml of 1,5-cyclooctadiene and 1.032 g of 2,2-bipyridyl are dissolved in 84 ml of DMF. .
1.5 g of 1,4-dichloroanthraquinone is dissolved in 20 ml of DMF, and this solution is added to the reaction solution under an N ₂ gas atmosphere and reacted at 60 ° C. for 48 hours. After completion of the reaction, the mixture is cooled, and the reaction solution is added dropwise to 1M hydrochloric acid to form a precipitate.
After collecting the precipitate by filtration, the solid obtained is washed twice with 1M hydrochloric acid, then once with methanol, then three times with aqueous 50 ° C. disodium ethylenediaminetetraacetate solution, then Washing with hot water at 50 ° C., and finally with methanol once.
The obtained solid was dissolved in chloroform, and methanol was added dropwise to crystallize to obtain the compound of the above formula (10).

  The obtained compound of the above formula (10) was dissolved in chloroform to obtain a 3 wt% solution, which was spin-coated on the transparent electrode 1 for 10 seconds under the condition of 3000 rpm. The transparent electrode in which the polyquinone film | membrane was formed was obtained by performing a drying process after that.

An organic dye was coated on each of the two types of polymer film electrodes 2 produced as described above.
As the organic dye 3, a compound represented by the formula (22) was applied.

  This organic dye was dissolved in ethanol to form a saturated solution, and sprayed in the form of a mist onto the polymer film electrode 2 formed as described above. Thereafter, it was dried and supported.

(Preparation of solution for electrolyte layer)
As a solution for forming the electrolyte layer 13, a solution in which potassium chloride was dissolved in water and adjusted to pH 8.0 was used.

(Lamination of electrode structure)
The connection part 14 was formed using the thermoplastic film adhesive with a thickness of 50 μm, and the display electrode 11 and the counter electrode 12 manufactured as described above were bonded to each other by heating to 90 ° C.
At this time, an inlet for injecting the electrolyte was secured in a process described later.

(Assembling the cell)
The display electrode 11 and the counter electrode 12 are inserted into a 30 × 30 × 5 mm cell. Next, an electrolytic solution was injected.
Thereafter, the upper part of the cell was covered and sealed with an epoxy thermosetting resin to obtain an electrochromic device having a pair of electrodes facing each other with the electrolyte layer 13 sandwiched therebetween.

(Evaluation of electrochromic device samples)
[Example 1]
An electrochromic device was produced using the display electrode 11 in which the polymer film electrode 2 was formed from the polyquinone compound represented by the above formula (7).
When a voltage of −0.05 V was applied between the display electrode 11 and the counter electrode 12 of this electrochromic device, magenta color development was immediately confirmed. FIG. 2 shows the spectrum during color development. The display change response speed was about 800 ms. Further, when 0.20 V was applied between the electrodes, it became transparent again immediately. The response speed of the display change was about 900 ms. As a result, it was confirmed that the speed was practically sufficient in both the coloring and decoloring reactions.
Further, when -0.05V and 0.20V were alternately applied 100 times repeatedly between the display electrode 11 and the counter electrode 12 of the electrochromic device in this example, the initial value even after 100 times of voltage application was repeated. It was confirmed that there was almost no change in the state and spectrum shape, and the durability was sufficiently excellent in practical use.

[Example 2]
An electrochromic device was produced using the display electrode in which the polymer film electrode 2 was formed from the polyquinone compound represented by the above formula (10).
When a voltage of -0.05 V was applied between the display electrode 11 and the counter electrode 12 of this electrochromic device, magenta color development was immediately confirmed. FIG. 3 shows the spectrum during color development. The response speed of the display change was 850 ms. Furthermore, when a voltage of 0.20 V was applied between the electrodes, it immediately became transparent again. The response speed of the display change was 900 ms. As a result, it was confirmed that the speed was practically sufficient in both the coloring and decoloring reactions.
Further, when -0.05V and 0.20V were alternately applied 100 times repeatedly between the display electrode 11 and the counter electrode 12 of the electrochromic device in this example, the initial value even after 100 times of voltage application was repeated. It was confirmed that there was almost no change in the state and spectrum shape, and the durability was sufficiently excellent in practical use.

  As is clear from the evaluation results described above, it was confirmed that the electrochromic device of the present invention has a narrow absorption wavelength width and can reversibly display a very clear and sharp color display.

[Comparative Example]
FIG. 4 shows a schematic configuration diagram of the electrochromic device in this example.
In the electrochromic device 20, an electrode 41 in which a transparent electrode 22 is formed on a transparent substrate 21 and an electrode 42 in which a transparent electrode 32 is formed on a transparent substrate 31 are opposed to each other through an organic dye-containing electrolyte layer 50. It has an arranged configuration.
As the transparent substrates 21 and 31, and the transparent electrodes 22 and 32, the same ones as in the above embodiment are applied.
The organic dye-containing electrolyte layer 50 contains an organic EC dye represented by the following formula (29).

(Preparation of display-side electrode 41)
On the transparent substrate 21 made of glass having a thickness of 1.1 mm, a transparent electrode 22 made of an FTO film of 15Ω / □ was formed in a plane.
(Preparation of organic dye-containing electrolyte layer 50)
Lithium perchlorate was dissolved in γ-butyrolactone to prepare a 0.1M solution.
Next, the compound of the above formula (29) was dissolved in a lithium perchlorate-γ-butyrolactone electrolyte solution so as to be 10 mmol / l.

(Preparation of the counter electrode 42)
On a glass transparent substrate 31 having a thickness of 1.1 mm, a transparent electrode 32 made of a 15Ω / □ FTO film in a planar manner was formed.

(Lamination of electrodes 41 and 42)
The display-side electrode and the counter-side electrode were bonded at 90 ° C. using a thermoplastic film adhesive having a thickness of 50 μm. At this time, an injection port was formed in a part so that the electrolyte solution could be injected in a later step.

(Injection of organic dye-containing electrolyte solution)
The electrolyte solution containing the organic dye was injected from the injection port and then sealed with an epoxy thermosetting resin to obtain a target electrochromic device.

(Evaluation of Comparative Example Electrochromic Device)
When a voltage of −1.8 V was applied between the display-side electrode 41 and the counter-side electrode 42, blue color was exhibited. The color development spectrum at this time is shown in FIG.
As is apparent from FIG. 5, it can be seen that the electrochromic device of the comparative example has an extremely broad absorption wavelength width as compared with the color spectrum of the electrochromic device of the present invention described above. This is highly likely to cause color mixing when a plurality of electrochromic elements are used to enable full color display, and it is difficult to display a sharp and clear image.

  As is clear from the above, according to the present invention, a polymer film electrode made of a polyquinone compound film is formed on a transparent electrode, and an organic dye is applied by utilizing the pH change of the electrolyte layer due to the structural change of the polyquinone compound. By adopting a structure for causing color development and decoloration, it was possible to provide an electrochromic device capable of displaying an image with a sharp color tone and having a stable and excellent durability.

The schematic block diagram of an example of the electrochromic apparatus of this invention is shown. The visible absorption spectrum at the time of coloring at the time of applying the compound of Formula (7) is shown. The visible absorption spectrum at the time of color development at the time of applying the compound of a formula (10) is shown. The schematic block diagram of the electrochromic apparatus in a comparative example is shown. The visible absorption spectrum at the time of color development at the time of applying the compound of a formula (29) is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transparent electrode, 2 ... Polymer film electrode, 3 ... Organic pigment | dye, 10 ... Electrochromic device, 11 ... Display electrode, 12 ... Counter electrode, 13 ... Electrolyte layer, 14 ... Connection part, 20 ... Electrochromic device, 21, 31 ... Transparent substrate, 22, 32 ... Transparent electrode, 41, 42 ... Electrode, 50 ... Organic dye-containing electrolyte layer

Claims (3)

A display electrode having a transparent electrode and a counter electrode are arranged via an electrolyte layer,
On the transparent electrode constituting the display electrode, a polymer film electrode made of a polyquinone compound having at least one of benzoquinone, naphthoquinone, and anthraquinone as a monomer is formed,
On the polymer film electrode or in the polymer film electrode, an organic dye that develops color in response to pH change is supported,
An electrochromic device, wherein a voltage is applied between the display electrode and the counter electrode to perform display by a reversible color-decoloring reaction of the organic dye. The electrochromic device according to claim 1, wherein the polyquinone compound is composed of at least one of the following general formulas (1), (2), (3), (4), and (5).

However, n is an integer for polymer formation. In the general formula (5), X is a hydrogen atom or an aliphatic hydrocarbon group, and Y is any of a hydrogen atom, an aliphatic hydrocarbon group, an ether group, or a hydroxy group. Represents A porous electrode is formed between the transparent substrate and the polymer film electrode, and the porous electrode has a mesoporous shape, a particle aggregate shape, a lot shape, a wire shape, a metal, a semiconductor material, or a highly conductive material. The electrochromic device according to claim 1, wherein the electrochromic device is formed of molecules.

Images