JP2008179725A - Colorant compound, manufacturing method of colorant compound and electrochromic device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a yellow colorant compound having a high color purity, capable of precise color control and contributable to displaying a sharp and clear full-color image, and to provide a manufacturing method suitable for the colorant compound and an elctrochromic device using the same. <P>SOLUTION: Provided is the electrochromic device in which a pair of the electrode structures 11, 12, each of which has at least the transparent electrodes 2, 7 formed on the supporting substrate 1, 6, are arranged with the electrolyte layer 5 held between them so that the transparent electrodes 2, 7 may face to each other and in which on at least one of a pair of the transparent electrodes 2, 7, there is formed the porous electrode 4 on which the colorant compound (organic EC colorant 3) consisting of a pyridine compound of a predetermined structure is adsorbed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a dye compound that is excellent in color development efficiency, response speed, and display color purity and is suitable for use as a display device, a method for producing the dye compound, and an electrochromic device using the same.

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 Many proposals have been made on light-emitting elements such as ELD.
However, since the above-mentioned various conventional light-emitting elements are used in such a manner that the user looks directly at the light emission, there is a problem that visual fatigue is caused when browsing for a long time.
In addition, mobile devices such as mobile phones are often used outdoors. For example, under sunlight, there is a problem in that visibility is deteriorated by canceling light emission.
In addition, LCD is a technology that is particularly in demand among light-emitting elements, and is used in various display applications, including large and small displays. However, it has a narrow viewing angle and is improved from the viewpoint of ease of viewing. There is a problem to be solved.

By the way, regarding the reflective display element, various techniques have been proposed in the past due to an increase in demand for electronic paper.
For example, a reflective LCD or an electrophoretic method can be used.
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 power saving 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, so There is a problem that the screen becomes 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.

In recent years, a device using an electrochromic (hereinafter abbreviated as EC) element has been proposed for a light control mirror, a timepiece or the like of an automobile.
This EC element does not require a polarizing plate, has no viewing angle dependency, has a color development type, has excellent visibility, has a simple structure and can be easily enlarged, and displays various colors depending on the choice of materials. Has the advantage of being possible.

As an example of a display device using a specific EC element, 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 is proposed. (For example, refer to Patent Documents 1 and 2).
These display devices can be held in a static state just by forming an open circuit to block the movement of electrons between the electrodes and maintaining the oxidation-reduction state, so no power is required to maintain the display image and consumption It is excellent in that the power is extremely low.

  Conventionally, a dye compound having a structure containing a quaternized pyridine ring is known. As a method for synthesizing such a dye compound, a pyridine compound and a halogenated alkylphosphonic acid ester are used. There has been proposed a method in which a phosphonic acid ester is hydrolyzed using hydrochloric acid, hydrobromic acid, or the like in the subsequent step to form a phosphonic acid structure (see, for example, Patent Document 3 and Non-Patent Document 1). ).

JP 2003-248242 A JP 2003-270670 A Special table 2006-519222 Solar Energy Materials and Solar Cells 55 (1998) 215-223

  However, since the synthesis method of the dye compound proposed in Patent Document 3 and Non-Patent Document 1 has a hydrolysis step, it cannot be extracted as a suitable structure depending on the target electrochromic dye compound. In some cases, it has been desired to improve the production method to cope with dye compounds having various structures in the future.

In addition, in the display devices proposed in the cited documents 1 and 2, a bipyridine compound called viologen is used as a display dye. It is not assumed to perform full color display.
Conventionally, no technical disclosure has been made on display devices using EC dyes that develop colors of cyan (C), magenta (M), and yellow (Y), which are required for full color display. The display device has been considered as a future problem in that it has low color purity and displays a precise and clear image.

  Therefore, in the present invention, in view of the problems of the prior art as described above, as a dye that can contribute to the formation of a full-color image, a proposal relating to an organic electrochromic compound capable of yellowing and decoloring is made. The present inventors have studied a suitable production method for such a dye compound, and have decided to provide an electrochromic device having high color purity, capable of forming a clear image, and excellent in repeated durability.

  In invention of Claim 1, the pigment | dye compound represented by following General formula (1) is provided.

In the general formula (1), a and b are integers satisfying a × b = 2, and Y ^b− represents a b-valent anion. R is an optionally substituted hydrocarbon group.

  The invention according to claim 2 comprises a step of reacting 2,5-bis (4-pyridyl) -1,3,4-oxadiazole with a compound represented by the following general formula (2). A method for producing a dye compound represented by the general formula (1) is provided.

However, in the above general formula (2), X represents iodine or bromine.
R is an optionally substituted hydrocarbon group.

In the general formula (1), a and b are integers satisfying a × b = 2, and Y ^b− represents a b-valent anion. R is an optionally substituted hydrocarbon group.

  In the invention of claim 3, the electrolyte layer is formed so that a pair of electrode structures (display electrode structure and counter electrode structure) having at least a transparent electrode formed on a support substrate face each other. Among the transparent electrodes constituting the pair of electrode structures, a porous electrode in which a dye compound of the following general formula (1) is adsorbed is provided on at least the transparent electrode of the display electrode structure. Provided is an electrochromic device which is formed and reversibly yellows and decolors by applying a voltage between the pair of electrode structures.

In the general formula (1), a and b are integers satisfying a × b = 2, and Y ^b− represents a b-valent anion. R is an optionally substituted hydrocarbon group.

  In the invention of claim 4, the electrolyte layer is formed so that a pair of electrode structures (display electrode structure and counter electrode structure) having at least a transparent electrode formed on a support substrate face each other. Between the transparent electrodes constituting the pair of electrode structures, the porous electrode in which the compound represented by the following general formula (1) is adsorbed is provided on at least the display electrode structure. In place of the compound represented by the following general formula (1), an electrochromic element that reversibly yellows and decolors yellow by applying a voltage between the pair of electrode structures, In place of an electrochromic element to which a dye compound that reversibly develops and decolors cyan by application and a compound represented by the following general formula (1), reversible emission of magenta by voltage application And the electrochromic device according to the dye compound to perform color is laminated to provide an electrochromic device and displaying a full-color image as a whole.

In the general formula (1), a and b are integers satisfying a × b = 2, and Y ^b− represents a b-valent anion. R is an optionally substituted hydrocarbon group.

  According to the present invention, a coloring compound suitable for full-color image formation capable of stably displaying a stable color development / decoloration many times, a production method suitable for such a coloring compound, and this dye were applied. Thus, an electrochromic device having excellent response speed and color development efficiency, high color purity and capable of precise image control was obtained.

The dye compound of the present invention, a method for producing the dye compound, and an electrochromic device using the dye compound 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 cross-sectional view of an example of an electrochromic device using the dye compound of the present invention as a display dye.
The electrochromic device 10 includes a display electrode structure 11 having a configuration in which a transparent electrode 2 and a porous electrode 4 on which an organic EC dye 3 which is a dye compound according to the present invention described later is supported are supported on a support substrate 1. And a counter electrode structure 12 having a configuration in which the transparent electrode 7 and the porous electrode 8 are provided on the support substrate 6, are arranged to face each other with the electrolyte layer 5 interposed therebetween.
In FIG. 1, porous electrodes 4 and 8 are formed on both of the opposing transparent electrodes 2 and 7, but the present invention is not limited to this configuration, and only one electrode is necessary if necessary. A porous electrode may be formed, and the organic EC dye 3 may be supported on the porous electrode. Hereinafter, the components will be sequentially described.

For the support substrates 1 and 6, a material having excellent heat resistance and high dimensional stability in the planar direction is suitable, and specifically, glass materials and various transparent resins are applied.
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.

The transparent electrodes 2 and 7 are formed as predetermined transparent electrode material layers.
Examples of the transparent electrode forming material 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.

The porous electrodes 4 and 8 are preferably composed of a material having a large surface area in order to ensure a high supporting function of the organic EC dye described later. Examples thereof include a porous shape having fine pores on the surface and inside, a lot shape, a wire shape, a mesoporous shape, and an aggregated particle shape.
As materials for the porous electrodes 4 and 8, for example, metals, intrinsic semiconductors, carbons, and the like can be applied. However, oxide semiconductors, composite oxide semiconductors, organic semiconductors, and the like are preferable because of high transmittance.
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.

Next, the organic EC dye 3 which is the dye compound of the present invention will be described.
The organic EC dye 3 is assumed to be carried on the surface of the porous electrode 4 and in the internal micropores, and in the present invention, a compound represented by the following general formula (1) is particularly applied.

However, in the general formula (1), a and b are integers satisfying a × b = 2, and Y ^b− represents a b-valent anion. This is fluorine ion, chlorine ion, bromine ion, iodine ion, perchlorate ion, periodate ion, hexafluorophosphate ion, hexafluoroantimonate ion, hexafluorostannate ion, phosphate ion, boron fluoride Inorganic acid ions such as hydrogenate ion and tetrafluoroborate ion, thiocyanate ion, benzenesulfonate ion, naphthalenesulfonate ion, naphthalene disulfonate ion, p-toluenesulfonate ion, alkylsulfonate ion, benzenecarboxylate ion , Alkyl carboxylate ions, trihaloalkyl carboxylate ions, alkyl sulfate ions, trihaloalkyl sulfate ions, nicotinate ions, tetracyanoquinodimethane ions and the like.
R is an optionally substituted hydrocarbon group.

The manufacturing method of the pigment | dye compound shown to the said General formula (1) is demonstrated.
The dye compound represented by the general formula (1) includes 2,5-bis (4-pyridyl) -1,3,4-oxadiazole and an iodinated or brominated alkyl represented by the following general formula (2). It can be obtained by reacting phosphonic acids in a suitable solvent.
In the synthesis, the compound of the following general formula (2) is preferably used in a 2-fold to 10-fold mole of 2,5-bis (4-pyridyl) -1,3,4-oxadiazole. 2.2 times mole to 4 times mole is particularly preferable.
When the ratio of the compound of the general formula (2) applied in the synthesis is smaller than the above numerical range, unreacted 2,5-bis (4-pyridyl) -1,3,4-oxadiazole remains. On the other hand, if the above numerical range is exceeded, it has been confirmed that purification of the target product becomes difficult, and it is not preferred from the viewpoint of economic efficiency in synthesis.

  However, in the above general formula (2), X represents iodine or bromine. R is an optionally substituted hydrocarbon group.

In the synthesis step, a conventionally known polar solvent is applied.
For example, polar solvents such as methanol, ethanol, propanol, isopropanol, dimethyl sulfoxide, N, N-dimethylformamide and the like can be mentioned, and N, N-dimethylformamide is particularly preferable.
The reaction temperature is preferably room temperature to reflux temperature, and more preferably 70 ° C to 120 ° C. If the temperature is too low, the reaction will not proceed sufficiently, while if it is too high, the quality of the product will deteriorate.
After the reaction, the product is precipitated in a reaction solvent, filtered, and subjected to purification treatment such as washing treatment or recrystallization treatment to obtain a pure product of the target dye compound.

  In addition, in the dye compound of the general formula (1), among the various functional groups shown in the proviso, it can be synthesized for all appropriately selected structures, and any of them is clear and sharp, which is an object of the present invention. It was confirmed that color display with good repeatability is possible.

Although the above general formula (1) is expressed as divalent, in the case of color development, it becomes a monovalent radical state by a reduction reaction.
This dye compound can be stabilized in a monovalent state and is extremely useful as a yellow coloring dye for display devices.
Specific examples of the pyridine compound represented by the general formula (1) are shown in the following formulas (3) to (8).

Next, a method for supporting the dye compound on the porous electrode 4 will be described.
Specific examples of the method for adsorbing the dye compound on the surface of the porous electrode 4 include a coating method such as spin coating, and a natural adsorption method in which the dye compound is immersed in a solution of the compound to be supported, and the natural adsorption method is particularly preferable. .

Examples of the natural adsorption method include a method in which a dye compound is dissolved in a predetermined solvent to prepare a solution, and a transparent electrode with a porous electrode 4 that has been previously dried is immersed, or the solution of the dye compound is used as the porous electrode 4. The method of apply | coating to is mentioned.
Since the dye compound of the present invention represented by the general formula (1) has a phosphonic acid group in the chemical structure, it can be reliably adsorbed to the porous electrode 4.

  As the solvent for dissolving the dye compound, conventionally known solvents can be applied, for example, water, alcohol, acetonitrile, propionitrile, dimethyl sulfoxide, N, N-dimethylformamide, N-methylpyrrolidone, esters, carbonates. , Ketones, hydrocarbons and the like. These may be used singly or may be used in combination as appropriate. Water is particularly preferable from the viewpoint of solubility.

FIG. 1 shows a configuration example in which the organic EC dye 3 as the dye compound of the present invention is supported only on the porous electrode 4 on the display electrode structure 11 side. It is not limited to the configuration.
In other words, the porous electrode 8 on the counter electrode structure 12 side may be configured to carry a predetermined organic EC dye. In this case, it is necessary to select materials so that the coloring reaction and the decoloring reaction are caused by the opposite reactions of the oxidation reaction and the reduction reaction.
For example, when the dye compound supported on the porous electrode 4 on the display electrode side becomes a radical state by the reduction reaction and develops color, the porous electrode 8 on the counter electrode side is supported on the porous electrode 4 in a steady state. A dye compound that has the same color tone as the pyridine dye and develops color by an oxidation reaction is selected.
As described above, by supporting the dye compound in both the electrode structures 11 and 12, in the finally obtained electrochromic device, the color development is clarified and the sharpness is improved.

The electrolyte layer 5 has a configuration in which a supporting electrolyte is dissolved 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 5 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 above-described dye compound (organic EC dye 3) is selected. For example, it is appropriately selected from water, acetonitrile, dimethylformamide, propylene carbonate, dimethyl sulfoxide, propylene carbonate, gamma butyrolactone, 3-methoxypropionitrile and the like.

Further, a so-called matrix material may be applied to the electrolyte layer 5.
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 5 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.

Next, a display method using the electrochromic device 10 shown in FIG. 1 will be described.
In the electrochromic device 10, the surface of the porous electrode 4 carries a pyridine compound represented by the general formula (1), which is an organic EC dye having no absorption in the visible region in a steady state.
A predetermined lead wire is connected to the pair of electrode structures 11 and 12 constituting the electrochromic device 10 to constitute a display device. When a predetermined voltage is applied between the electrodes through a predetermined lead wire, electrons are transferred between the porous electrode 4 and the organic EC dye 3 carried on the porous electrode 4, and an electrochemical reduction reaction occurs in the organic EC dye. Wake up to form a radical state and color yellow.

The electrochromic device of the present invention is not limited to the monochromatic display configuration shown in FIG. 1, and can be applied to a multi-color display device configuration.
That is, the above-described display device shown in FIG. 1 is used as a first display element for yellow display, and reversible cyan color reversal by applying voltage in place of the compound represented by the general formula (1). A second display element to which a dye compound for applying color is applied and a third display element to which a dye compound for performing reversible color development of magenta by applying a voltage in place of the compound of general formula (1) is combined Thus, an electrochromic device that enables full color display as a whole can be obtained.

  Next, specific examples of the electrochromic device of the present invention and a comparative example thereof will be described.

[Example 1]
(Dye compound (organic EC dye: compound of the above formula (3)) is synthesized.)
6.86 g (0.05 mol) of isothianiide and 12.3 g (0.1 mol) of isonicotinic acid were mixed, 25 ml of phosphoryl chloride was added, and the mixture was heated to reflux at 120 ° C. for 5 hours.
The reaction solution was neutralized with an aqueous sodium hydroxide solution while being cooled to 0 ° C. with ice water.
The resulting precipitate was filtered and washed with water.
The obtained powder was dissolved in hydrochloric acid while being cooled to 0 ° C., and neutralized with an aqueous sodium hydroxide solution.
Thereafter, the precipitate was filtered and recrystallized from methanol, whereby 4.31 g (yield: 38. 2) of colorless crystals of 2,5-bis (4-pyridyl) 1,3,4-oxadiazole. 5%). As a result of NMR measurement, ¹ H-NMR (DMSO) δ: 8.87 (2H, d, J = 5.4 Hz), 8.07 (2H, d, J = 5.1 Hz). .

Under an N ₂ atmosphere, 80 ml of dry chloroform was added to 19.6 g (0.08 mol) of diethyl 2-bromoethylphosphonate, and 40 ml (0.24 mol) of bromotrimethylsilane was added at 0 ° C.
After stirring at 0 ° C. for 1 hour, the mixture was returned to room temperature and further stirred for 2 hours.
Furthermore, 14 ml (0.08 mol) of bromotrimethylsilane was added, and the mixture was heated and stirred at 40 ° C. for 5 hours.
Thereafter, the solvent was distilled off, 40 ml of water and 40 ml of methanol were added, and the mixture was stirred at 30 ° C. for 10 hours.
Thereafter, methanol was distilled off, washed with dichloromethane, water was distilled off, and drying treatment was performed to obtain 13.94 g (yield 92.2%) of 2-bromoethylphosphonic acid as a light pink powder. It was. As a result of NMR measurement, ¹ H-NMR (D ₂ O) δ: 3.37 (2H, dt, J = 14.6, 6.2 Hz), 2.21 (2H, dt, J = 18.1, 8.0 Hz). Generation was confirmed.

2,5-bis (4-pyridyl) -1,3,4-oxadiazole 1.3 g (5.8 mmol) was dissolved in 14 ml of DMF, and 3.3 g (17.5 mmol) of 2-bromoethylphosphonic acid was added. The mixture was stirred at 100 ° C. for 24 hours.
The resulting precipitate was filtered, 30 ml of DMF was added, the mixture was stirred at 100 ° C. for 30 minutes, filtered hot, washed with acetone, and the target pale yellow powder, which is the compound of formula (3), was obtained. 1 g (yield 88.8%) was obtained. As a result of NMR measurement, ¹ H-NMR (D ₂ O) δ: 9.15 (4H, d, J = 5.9 Hz), 8.71 (4H, d, J = 5.6 Hz), 4.89-4.76 (4H, m) , 2.38-2.30 (4H, m). The production of the above compound was confirmed.

(Preparation of display electrode structure)
On a support substrate 1 made of glass having a thickness of 1.1 mm, a 15 Ω / □ FTO film (transparent electrode 2) was formed in a plane.
Next, polyethylene glycol was dissolved at a rate of 5% by weight in a slurry in which 15% by weight of titanium oxide having a primary particle diameter of 20 nm was dispersed in an aqueous hydrochloric acid solution having a pH of about 1.0 to prepare a coating material. This paint was applied on the FTO film by a squeegee method.
Next, an FTO substrate on which a titanium oxide porous electrode 4 having a film thickness of 5 μm is formed by performing a drying treatment at 80 ° C. for 15 minutes on a hot plate and further sintering at 500 ° C. for 1 hour in an electric furnace. Obtained.

(Adsorption of organic EC dye to porous electrode)
The FTO substrate on which the porous electrode 4 made of the titanium oxide film is formed is dipped in a 5 mM aqueous solution of a predetermined pyridine compound (EC dye) prepared as described above for 24 hours, and the dye (organic EC) is placed on the titanium oxide electrode. Dye film) was adsorbed.
Thereafter, washing treatment and drying treatment were performed with an ethanol solution.

(Preparation of counter electrode structure)
On a glass support substrate 6 having a thickness of 1.1 mm, a 15Ω / □ FTO film (transparent electrode 7) was formed in a plane.
Next, polyethylene glycol was dissolved at a ratio of 5% by weight in a slurry in which 20% by weight of antimony-doped tin oxide having a primary particle diameter of 20 nm was dispersed in an acidic aqueous solution to prepare a paint. This paint was applied on the FTO film by a squeegee method.
Next, the FTO was dried on a hot plate at 80 ° C. for 15 minutes, further sintered in an electric furnace at 500 ° C. for 1 hour, and an antimony-doped tin oxide porous electrode 8 having a thickness of 12 μm was formed. A substrate was obtained.

(Preparation of solution for electrolyte layer)
As the electrolyte layer 5 forming solution, a solution obtained by dissolving 0.1 mol / L of lithium perchlorate in gamma-butyrolaclone, dehydrating and degassing was applied.

(Lamination of electrode structure)
Adhesion of display electrode structure (substrate with dye-adsorbed titanium oxide porous electrode) and counter electrode structure (substrate with antimony-doped tin oxide porous electrode) produced as described above to a thermoplastic film having a thickness of 50 μm Using an agent, bonding was performed at 90 ° C.
At this time, an injection port was formed in a part so that the electrolyte solution could be injected by a process described later.

(Injection of electrolyte solution)
The electrolytic solution was vacuum injected from the injection port.
Thereafter, the injection port was sealed with an epoxy-based thermosetting resin, thereby completing an electrochromic device including electrode structures facing each other with the electrolyte layer sandwiched therebetween.

When a voltage of −1.6 V was applied between the display electrode and the counter electrode of this electrochromic device, the color was immediately developed to yellow. FIG. 2 shows the spectrum during color development. The response speed of the display change is about 150 ms, which is a sufficiently good speed for practical use.
Furthermore, when 0.5 V was applied between the electrodes, it became transparent again immediately. The response speed of the display change was about 90 ms.
Furthermore, -1.6V and 0.5V were alternately applied 1 million times at 1 Hz between the display electrode and the counter electrode of the electrochromic device in this example, but even after the voltage application was repeated 1 million times. Almost no change in the initial state and spectrum shape was observed, and it was confirmed that the material had sufficiently excellent durability for practical use.

[Comparative example]
In this example, an attempt was made to synthesize a dye compound represented by the above formula (3) by a method different from that in Example 1.
25 ml of phosphoryl chloride was added to 6.86 g (0.05 mol) of isothiamide and 12.3 g (0.1 mol) of isonicotinic acid, and the mixture was heated to reflux at 120 ° C. for 5 hours.
The reaction solution was neutralized with an aqueous sodium hydroxide solution while being cooled to 0 ° C. with ice water.
The resulting precipitate was filtered and washed with water.
The obtained powder was dissolved in hydrochloric acid while being cooled to 0 ° C., and neutralized with an aqueous sodium hydroxide solution.
The precipitate was filtered and recrystallized with methanol to obtain 4.31 g of colorless crystals of 2,5-bis (4-pyridyl) 1,3,4-oxadiazole (yield 38.5%). ) Obtained. As a result of NMR measurement, ¹ H-NMR (DMSO) δ: 8.87 (2H, d, J = 5.4 Hz), 8.07 (2H, d, J = 5.1 Hz). .

To 0.2 g (0.89 mmol) of 2,5-bis (4-pyridyl) 1,3,4-oxadiazole, 2 ml of diethyl 2-bromoethylphosphonate was added and stirred with heating at 90 ° C. for 1 day.
Washing was performed several times with acetone, 20 ml of water and 10 ml of hydrochloric acid were added, and the mixture was heated and stirred for 1 day.
Then, the solvent was distilled off and washed with acetone to obtain 0.21 g of light green powder.
When the obtained powder was analyzed by LC-MS and ¹ H-NMR, the production of the compound of the above formula (3) was not confirmed.

  In addition, an electrochromic device was produced by the same method as in Example 1 using the light green powder produced in the above comparative example, and voltage was applied between the electrodes, but no color development occurred.

  From the results of Example 1 and Comparative Example, the dye compound represented by the general formula (1) can be synthesized by following the steps shown in the method of the present invention. When this is applied as a display dye, Thus, it is possible to obtain a yellow-colored electrochromic device that is extremely excellent in response and has a sharp color tone and can stably perform reversible color-decoloring display.

[Example 2]
As the dye compound (organic EC dye), the compounds represented by the following formulas (9) and (10) were applied, and the others were the same as in Example 1 above, and a magenta electrochromic element and cyan electrochromic element were used. A chromic element was produced.

  A yellow-colored electrochromic element manufactured according to Example 1 above, the magenta-colored electrochromic element, and the cyan-colored electrochromic element are combined to form a three-layer structure, and between the two electrodes constituting each element By controlling the voltage independently, full color display, that is, any mixed color display is performed, and desired reversible color generation such as yellow, magenta, cyan, red, green, blue, and black is performed. An electrochromic device was obtained.

1 shows a schematic cross-sectional view of an example of an electrochromic device of the present invention. The visible absorption spectrum at the time of color development at the time of applying the pigment compound of a formula (3) is shown.

Explanation of symbols

16 ... support substrate, 2 ... transparent electrode, 3 ... organic EC dye, 4,8 ... porous electrode, 5 ... electrolyte layer, 10 ... electrochromic device, 11 ... display electrode structure, 12 ... Counter electrode structure

Claims (4)

A dye compound represented by the general formula (1).

However, in the general formula (1), a and b are integers satisfying a × b = 2, and Y ^b− represents a b-valent anion. R is an optionally substituted hydrocarbon group. 2,5-bis (4-pyridyl) -1,3,4-oxadiazole;
The manufacturing method of the pigment | dye compound represented by the following general formula (1) characterized by performing the process with which the compound represented by the following general formula (2) is made to react.

However, in the above general formula (2), X represents iodine or bromine.
R is an optionally substituted hydrocarbon group.

In the general formula (1), a and b are integers satisfying a × b = 2, and Y ^b− represents a b-valent anion. R is an optionally substituted hydrocarbon group. A pair of electrode structures (a display electrode structure and a counter electrode structure) in which at least a transparent electrode is formed on a support substrate are arranged with an electrolyte layer sandwiched so that the transparent electrodes face each other,
A porous electrode on which a compound represented by the following general formula (1) is adsorbed is formed on at least the display electrode structure of the transparent electrodes constituting the pair of electrode structures,
An electrochromic device that performs reversible yellowing and decoloring of yellow by applying a voltage between the pair of electrode structures.

In the general formula (1), a and b are integers satisfying a × b = 2, and Y ^b− represents a b-valent anion. R is an optionally substituted hydrocarbon group. A pair of electrode structures (a display electrode structure and a counter electrode structure) in which at least a transparent electrode is formed on a support substrate are arranged with an electrolyte layer sandwiched so that the transparent electrodes face each other, Among the transparent electrodes constituting the pair of electrode structures, a porous electrode on which a dye compound represented by the following general formula (1) is adsorbed is formed on at least the transparent electrode on the display electrode structure side, An electrochromic element that performs reversible yellowing and decoloring of yellow by applying a voltage between a pair of electrode structures;
In place of the dye compound represented by the following general formula (1), an electrochromic element to which a dye compound that performs reversible cyan decoloration by applying a voltage is applied;
In place of the compound represented by the following general formula (1), an electrochromic device to which a dye compound that performs reversible color development of magenta by applying voltage is applied, and is laminated.
An electrochromic device that displays a full-color image as a whole.

In the general formula (1), a and b are integers satisfying a × b = 2, and Y ^b− represents a b-valent anion. R is an optionally substituted hydrocarbon group.

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