JP2017111434A - Electrochromic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrochromic device using an oxidation coloring electrochromic compound, wherein the electrochromic device can be driven at low voltage.SOLUTION: An electrochromic device has a first electrode 2, a second electrode 3, and an electrolyte between the first electrode 2 and second electrode 3; has a layer 4 comprising an oxidation coloring electrochromic compound on the first electrode 2; and has a layer comprising a compound of the general formula (1) on the second electrode 3. In the general formula (1), R-Rindependently represent a hydrogen atom, a halogen atom, or a monovalent organic group, where at least one of R-Rhas a functional group which can bond a hydroxy group directly or indirectly.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electrochromic device.

A phenomenon in which a redox reaction occurs reversibly and a color changes reversibly by applying voltage is called electrochromism. In general, an oxidation-reduction reaction is performed in an electrochromic device in which an electrolyte layer capable of ion conduction is provided between two opposing electrodes. When a reduction reaction occurs in the vicinity of one of the two electrodes facing each other, an oxidation reaction that is a reverse reaction occurs in the vicinity of the other electrode. In such an electrochromic element, when a transparent display device is to be obtained, a device having a structure in which three color-developing layers of cyan (C), magenta (M), and yellow (Y) are laminated is constructed. In this case, it is important that the material is made of a material having a colorless and transparent state.
Examples of such a material include a viologen compound exhibiting an electrochromic phenomenon that is transparent in a neutral state and develops a color in a reduced state. Triarylamine compounds and the like have been reported as oxidative coloring electrochromic materials that are transparent in the neutral state and develop color in the oxidized state (see Non-Patent Documents 1 and 2).

On the other hand, the present applicant has proposed an electrochromic device using a triarylamine compound that is capable of stable operation and excellent in light durability in a previous application (Japanese Patent Application No. 2015-134017). However, a technique relating to the reduction side of the counter electrode, particularly a technique that enables driving at a low voltage using an oxidative coloring electrochromic material has not been studied.
In another prior application (Japanese Patent Application No. 2014-171858), a good electrochromic device having a high contrast, in which a reducing viologen and an oxidizing triarylamine were combined, was proposed. However, since both the reducing side and the oxidizing side are colored, there is a problem that it is difficult to obtain a color only on the oxidizing side.
Thus, there is no known document or known technique that discloses a technique for improving the chromic characteristics, in particular, driving at a low voltage, using an oxidative coloring electrochromic material.

  An object of the present invention is to solve the above-mentioned conventional problems and to provide an electrochromic device that can be driven at a low voltage using an oxidative coloring electrochromic compound.

（上記式中、Ｒ_１〜Ｒ_５は、各々独立に水素原子、ハロゲン原子、一価の有機基を表し、Ｒ_１〜Ｒ_５の中の少なくとも一つは、水酸基に対し直接又は間接的に結合できる官能基を有する。） As a result of intensive studies to solve the above problems, the present inventors can drive at a low voltage by providing a layer containing a compound having a phenol structure, particularly a hindered phenol structure, on the second electrode. It was found that an electrochromic device can be obtained.
That is, the above problem is solved by the following invention 1).
1) In an electrochromic device having a first electrode, a second electrode, and an electrolyte between the first electrode and the second electrode, an oxidative coloring electrochromic compound is contained on the first electrode. An electrochromic device comprising a layer and a layer containing a specific compound represented by the following general formula (1) on the second electrode.
General formula (1)

(In the above formula, R _{1 to} R ₅ each independently represent a hydrogen atom, a halogen atom, or a monovalent organic group, and at least one of R _{1 to} R ₅ is directly or indirectly to the hydroxyl group. It has a functional group that can be bound.)

  ADVANTAGE OF THE INVENTION According to this invention, the electrochromic element which can be driven with a low voltage using the oxidation coloring electrochromic compound can be provided. Also, this element. Since it does not absorb in the visible range and does not show reductive coloring, it is possible to obtain the color of only the oxidative coloring electrochromic compound used.

It is the schematic which shows an example of the electrochromic element of this invention. 4 is an IV characteristic diagram in CV measurement of the element of Example 1. FIG. 6 is a TV characteristic diagram in CV and transmittance measurement of the element of Example 1. FIG. 5 is an IV characteristic diagram in CV measurement of the element of Comparative Example 1. FIG. 6 is a TV characteristic diagram in CV and transmittance measurement of the element of Comparative Example 1. FIG. 4 is an IV characteristic diagram in CV measurement of the element of Comparative Example 2. FIG.

Hereinafter, the present invention 1) will be described in detail, but the following 2) to 7) are also included in the embodiment, and these will also be described together.
2) The monovalent organic group in the specific compound is an alkyl group, alkenyl group, alkynyl group, aryl group, heteroaryl group, alkoxy group, aryloxy group, or heteroaryloxy group 1) The electrochromic device described in 1.
3) The electrochromic device according to 1) or 2), wherein R ₃ in the specific compound has a functional group capable of directly or indirectly binding to a hydroxyl group.
4) The functional group capable of directly or indirectly bonding to the hydroxyl group is a phosphonic acid group, a phosphoric acid group, a carboxylic acid group, a sulfonyl group, a silyl group, or a silanol group 1) To 3).
5) The functional group capable of directly or indirectly bonding to the hydroxyl group has an alkyl group, an aryl group, or an aryl group substituted with an alkyl group, any one of 1) to 4) The electrochromic device described in 1.
6) The electrochromic according to any one of 1) to 5), wherein the specific compound is bonded or adsorbed to a conductive or semiconducting nanostructure provided on the second electrode. element.
7) The layer containing the specific compound represented by the general formula (1) is a counter electrode layer provided on the second electrode, According to any one of 1) to 5), Electrochromic element.

（上記式中、Ｒ_１〜Ｒ_５は、各々独立に水素原子、ハロゲン原子、一価の有機基を表し、Ｒ_１〜Ｒ_５の中の少なくとも一つは、水酸基に対し直接又は間接的に結合できる官能基を有する。） (Electrochromic device)
The electrochromic device of the present invention includes a first electrode, a second electrode, and an electrolyte between the first electrode and the second electrode, and further includes other members as necessary.
Moreover, it has a layer containing an oxidative coloring electrochromic compound on the first electrode, and a layer containing a specific compound represented by the following general formula (1) on the second electrode.
General formula (1)

(In the above formula, R _{1 to} R ₅ each independently represent a hydrogen atom, a halogen atom, or a monovalent organic group, and at least one of R _{1 to} R ₅ is directly or indirectly to the hydroxyl group. It has a functional group that can be bound.)

<Specific compound represented by general formula (1)>
The specific compound is present on the second electrode, but may be present in a state of being bound, adsorbed, or mixed with a counter electrode layer or the like provided on the second electrode.
R _{1 to} R ₅ are a hydrogen atom, a halogen atom, or a monovalent organic group, and may be the same or different.
Each of the monovalent organic groups independently has a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxyl group, an alkoxycarbonyl group which may have a substituent, or a substituent. An aryloxycarbonyl group which may have a substituent, an alkylcarbonyl group which may have a substituent, an arylcarbonyl group which may have a substituent, an amide group, a monoalkylaminocarbonyl which may have a substituent Group, dialkylaminocarbonyl group optionally having substituent, monoarylaminocarbonyl group optionally having substituent, diarylaminocarbonyl group optionally having substituent, sulfonic acid group, substituted An alkoxysulfonyl group which may have a group, an aryloxysulfonyl group which may have a substituent, and a substituent. Alkylsulfonyl group which may have a substituent, arylsulfonyl group which may have a substituent, sulfonamido group, monoalkylaminosulfonyl group which may have a substituent, dialkylaminosulfonyl which may have a substituent Group, monoarylaminosulfonyl group which may have a substituent, diarylaminosulfonyl group which may have a substituent, amino group, monoalkylamino group which may have a substituent, substituent A dialkylamino group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, a substituent An aryl group which may have, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, and a substituent which may have Alkylthio group which may have a substituent arylthio group, and a heterocyclic group which may have a substituent.
Among these, an alkyl group, an alkoxy group, a hydrogen atom, an aryl group, an aryloxy group, a heteroaryl group, a heteroaryloxy group, a halogen group, an alkenyl group, and an alkynyl group are particularly preferable from the viewpoint of stable operation and light durability. .

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group.
Examples of the aryl group include a phenyl group and a naphthyl group.
Examples of the aralkyl group include a benzyl group, a phenethyl group, and a naphthylmethyl group.
Examples of the alkoxy group include a methoxy group, an ethoxy group, and a propoxy group.
Examples of the aryloxy group include a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 4-methoxyphenoxy group, and a 4-methylphenoxy group.
Examples of the heterocyclic group include carbazole, dibenzofuran, dibenzothiophene, oxadiazole, thiadiazole, and the like.

  Examples of the substituent further substituted with the substituent include an alkyl group such as a halogen atom, a nitro group, a cyano group, a methyl group and an ethyl group, an alkoxy group such as a methoxy group and an ethoxy group, and an aryloxy group such as a phenoxy group. Group, aryl group such as phenyl group and naphthyl group, and aralkyl group such as benzyl group and phenethyl group.

また前記水酸基に対し直接又は間接的に結合することができる官能基としては、アルキル基、アリール基、又はアルキル基で置換されたアリール基を含む基などが挙げられる。
前記アルキル基としては、例えば、メチル基、エチル基、プロピル基、ブチル基などが挙げられる。
前記アリール基としては、例えば、フェニル基、ナフチル基などが挙げられる Examples of the functional group that can be directly or indirectly bonded to the hydroxyl group include a group containing a phosphonic acid group, a phosphoric acid group, a carboxylic acid group, a sulfonyl group, a silyl group, and a silanol group, and the following are preferable. .

In addition, examples of the functional group that can be directly or indirectly bonded to the hydroxyl group include an alkyl group, an aryl group, and a group containing an aryl group substituted with an alkyl group.
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group.
Examples of the aryl group include a phenyl group and a naphthyl group.

Although the specific example of the said specific compound is shown below, it is not necessarily limited to these compounds.

<Oxidative coloring electrochromic compound>
In the present invention, a layer containing an oxidative coloring electrochromic compound is provided on the first electrode. Usable oxidative coloring electrochromic compounds include azobenzene-based, tetrathiafulvalene-based, triphenylmethane-based, triphenylamine-based and leuco dyes, among which compounds having a triarylamine skeleton are preferable.

As the compound having a triarylamine skeleton, those represented by the following general formulas 2 to 4 are suitable.
General formula 2

General formula 3

Formula 4

R _{27 to} R ₈₉ in the general formulas 2 to 4 are monovalent organic groups, which may be the same or different.
As said monovalent organic group, the thing similar to what was illustrated by paragraphs 0010-0012 about the monovalent organic group in R < ₁ > -R < ₅ > of General formula (1) is mentioned.

The layer containing the oxidative coloring electrochromic compound is not particularly limited as long as it is compatible with the electrolyte. For example, it may exist on the first electrode as a low molecule, or may exist in a state of being cured by a photocrosslinking group such as acrylate or methacrylate. Moreover, you may exist in the state couple | bonded or adsorb | sucked to the carrying | support particle | grains or electroconductive particle.
The average thickness of the layer containing the oxidative coloring electrochromic compound is preferably from 0.1 to 30 μm, more preferably from 0.4 to 10 μm.

The specific compound is preferably bonded or adsorbed to a conductive or semiconducting nanostructure provided on the second electrode.
The material constituting the conductive or semiconducting nanostructure is preferably a metal oxide in terms of transparency and conductivity. Examples of such metal oxides include titanium oxide, zinc oxide, tin oxide, zirconium oxide, cerium oxide, yttrium oxide, boron oxide, magnesium oxide, strontium titanate, potassium titanate, barium titanate, calcium titanate. Metal oxides mainly composed of calcium oxide, ferrite, hafnium oxide, tungsten oxide, iron oxide, copper oxide, nickel oxide, cobalt oxide, barium oxide, strontium oxide, vanadium oxide, aluminosilicate, calcium phosphate, aluminosilicate, etc. Used. Moreover, these metal oxides may be used independently and 2 or more types may be mixed and used.

<First electrode and second electrode>
The material of the first electrode and the second electrode is not particularly limited as long as it is a transparent material having conductivity, and can be appropriately selected according to the purpose. Examples thereof include indium oxide doped with tin (ITO), tin oxide doped with fluorine (FTO), tin oxide doped with antimony (ATO), and inorganic materials such as zinc oxide. Among these, InSnO, GaZnO, SnO, In ₂ O ₃ and ZnO are preferable.
Furthermore, a carbon nanotube having transparency, other highly conductive non-permeable materials such as Au, Ag, Pt, and Cu are formed in a fine network shape, and an electrode having improved conductivity while maintaining transparency. It may be used.
The thickness of each of the first electrode and the second electrode is adjusted so that an electrical resistance value necessary for the oxidation-reduction reaction of the electrochromic layer can be obtained.
As for each thickness at the time of using ITO as a material of a 1st electrode and a said 2nd electrode, 50-500 nm is preferable, for example.

As a method for manufacturing the first electrode and the second electrode, a coating method, a printing method, a vacuum evaporation method, a sputtering method, an ion plating method, or the like can be used.
In the case of the coating method, there is no particular limitation as long as each material of the first electrode and the second electrode can be formed by coating, for example, spin coating method, casting method, micro gravure coating method, gravure coating method, A bar coating method, a roll coating method, a wire bar coating method, a dip coating method, a slit coating method, a capillary coating method, a spray coating method, a nozzle coating method, and the like can be used.
As the printing method, various printing methods such as a gravure printing method, a screen printing method, a flexographic printing method, an offset printing method, a reverse printing method, and an ink jet printing method can be used.

<Electrolyte>
The electrolyte is filled between the first electrode and the second electrode.
As the electrolyte, for example, inorganic ion salts such as alkali metal salts and alkaline earth metal salts, quaternary ammonium salts, acids and supporting salts of alkalis can be used. Specific examples include LiClO ₄ , LiBF ₄ , LiAsF ₆ , LiPF ₆ , LiCF ₃ SO ₃ , LiCF ₃ COO, KCl, NaClO ₃ , NaCl, NaBF ₄ , NaSCN, KBF ₄ , Mg (ClO ₄ ) ₂ Mg ( BF ₄ ) _{2 and the} like.

An ionic liquid can also be used as the electrolyte material. Among these, organic ionic liquids are preferable because they have a molecular structure that shows liquids in a wide temperature range including room temperature.
Examples of the cationic component in the molecular structure include imidazole derivatives such as N, N-dimethylimidazole salt, N, N-methylethylimidazole salt, and N, N-methylpropylimidazole salt; N, N-dimethylpyridinium salt, N And pyridinium derivatives such as N-methylpropylpyridinium salt; aliphatic quaternary ammonium compounds such as trimethylpropylammonium salt, trimethylhexylammonium salt and triethylhexylammonium salt. Similarly, it is preferable to use a fluorine-containing compound as the anion component in consideration of stability in the atmosphere. For example, BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , PF ₄ ⁻ , (CF ₃ SO ₂ ) ₂ N- ^{and the} like.

As an electrolyte material, it is preferable to use an ionic liquid in which the cation component and the anion component are arbitrarily combined.
The ionic liquid may be directly dissolved in any of photopolymerizable monomers, oligomers, and liquid crystal materials. If the solubility is poor, the solution may be dissolved in a small amount of solvent and mixed with any of photopolymerizable monomers, oligomers, and liquid crystal materials.
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, or a mixed solvent thereof.

The electrolyte does not need to be a low-viscosity liquid, and can take various forms such as a gel, a polymer cross-linking type, and a liquid crystal dispersion type. When the electrolyte is in the form of a gel or solid, advantages such as improved element strength and improved reliability can be obtained.
As the solidification method, a method of holding the electrolyte and the solvent in the polymer resin is preferable. This provides high ionic conductivity and solid strength.
Further, the polymer resin is preferably a photocurable resin. This is because the device can be manufactured at a low temperature and in a short time as compared with the method of thinning by thermal polymerization or evaporation of the solvent.
There is no restriction | limiting in particular in the average thickness of the electrolyte layer which consists of electrolytes, Although it can select suitably according to the objective, 100 nm-10 micrometers are preferable.

<Counter electrode layer>
The role of the counter electrode layer is to reverse the chemical reaction with the electrochromic layer, balance the charge, and cause the first and second electrodes to corrode or deteriorate due to irreversible redox reactions. It is to suppress. The reverse reaction includes acting as a capacitor in addition to the case where the counter electrode layer is oxidized and reduced.
The material of the counter electrode layer is not particularly limited as long as it is a material that plays a role of preventing corrosion due to the irreversible oxidation-reduction reaction of the first electrode and the second electrode, and may be appropriately selected according to the purpose. it can. Examples thereof include antimony tin oxide, nickel oxide, titanium oxide, zinc oxide, tin oxide, or a conductive or semiconductive metal oxide containing a plurality thereof.
When importance is attached to prevention of deterioration, the counter electrode layer can be composed of a porous thin film that does not hinder electrolyte injection. For example, conductive or semiconductive metal oxide fine particles such as antimony tin oxide, nickel oxide, titanium oxide, zinc oxide, tin oxide, for example, acrylic, alkyd, isocyanate, urethane, epoxy, phenol, etc. By fixing to the second electrode with this binder, it is possible to obtain a suitable porous thin film satisfying the electrolyte permeability and the function as a deterioration preventing layer.

<Other members>
There is no restriction | limiting in particular as said other member, According to the objective, it can select suitably, For example, a support body, an insulating porous layer, a protective layer, etc. are mentioned.
-Support-
As the support, a known organic material or inorganic material can be used as it is as long as it is a transparent material capable of supporting each layer.
Examples thereof include glass substrates such as alkali-free glass, borosilicate glass, float glass, and soda lime glass. Further, a resin substrate such as polycarbonate resin, acrylic resin, polyethylene, polyvinyl chloride, polyester, epoxy resin, melamine resin, phenol resin, polyurethane resin, or polyimide resin may be used. Moreover, in order to improve water vapor barrier property, gas barrier property, ultraviolet resistance, and visibility, the surface of the support may be coated with a transparent insulating layer, a UV cut layer, an antireflection layer, or the like.
The shape of the support may be rectangular or round, and is not particularly limited.
The support may be a laminate of a plurality of materials. For example, when the electrochromic light control element is sandwiched between two glass substrates, the water vapor barrier property and the gas barrier property can be improved.

-Insulating porous layer-
The insulating porous layer functions to keep the electrolyte while isolating the first electrode and the second electrode so as to be electrically insulated.
The material of the insulating porous layer is not particularly limited as long as it is porous, and it is preferable to use organic materials and inorganic materials having high insulating properties and durability and excellent film forming properties, and composites thereof.
As a method for forming the insulating porous layer, for example, a sintering method (using fine pores formed between particles by partially fusing polymer fine particles or inorganic particles by adding a binder or the like), extraction method, etc. (After forming a constituent layer with a solvent-soluble organic substance or inorganic substance and a binder that does not dissolve in the solvent, the organic substance or inorganic substance is dissolved with the solvent to obtain pores), foaming method for foaming, good solvent and poor solvent For example, a phase inversion method in which a mixture of polymers is phase-separated and a radiation irradiation method in which various radiations are radiated to form pores.

-Protective layer-
The role of the protective layer is to protect the device from external stress and chemicals in the cleaning process, to prevent electrolyte leakage, and to prevent the entry of unnecessary substances such as moisture and oxygen in the atmosphere for stable operation of the electrochromic device. To prevent it.
As a material for the protective layer, for example, an ultraviolet curable resin or a thermosetting resin can be used, and specific examples include acrylic, urethane, and epoxy resins.
There is no restriction | limiting in particular in the thickness of a protective layer, Although it can select suitably according to the objective, 1-200 micrometers is preferable.

Here, an example of the configuration of the electrochromic device of the present invention is shown in FIG.
The electrochromic device of FIG. 1 includes a support (1), a first electrode (2), a second electrode (3) provided to face the electrode at a distance, and between the two electrodes. The electrolyte (5).
The surface of the first electrode (2) has a layer (4) containing the oxidative coloring electrochromic compound according to the present invention. The specific compound (6) according to the present invention is present in a state of adhering or adsorbing to the counter electrode layer (7). The layer (4) develops color by an oxidation reaction on the surface of the first electrode and is decolored by a reverse reaction (reduction reaction).

-Application-
The electrochromic device of the present invention can operate stably, and is particularly excellent in transparency and light durability. Therefore, electrochromic displays, large display boards such as stock price display boards, anti-glare mirrors, dimmer elements such as dimmer glass, low-voltage drive elements such as touch panel key switches, optical switches, optical memories, electronic paper, electronic It can be suitably used for albums and the like.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated further more concretely, this invention is not limited at all by these Examples. In the examples, “part” is “part by mass”.

・ＩＲＧＡＣＵＲＥ１８４（ＢＡＳＦジャパン社製）：５部
・２官能アクリレートを有するＰＥＧ４００ＤＡ（日本化薬社製）：５０部
・メチルエチルケトン：９００部

得られた酸化発色性エレクトロクロミック組成物を、第１の電極としてのＩＴＯガラス基板（４０ｍｍ×４０ｍｍ、厚み０．７ｍｍ、ＩＴＯ膜厚：約１００ｎｍ）上にスピンコート法で塗布した。得られた塗布膜に、ＵＶ照射装置（ウシオ電機社製、ＳＰＯＴ ＣＵＲＥ）を用いて１０ｍＷで６０秒間ＵＶ照射し、６０℃で１０分間アニール処理を行って、平均厚み０．４μｍの架橋したエレクトロクロミック層を形成した。 Example 1
-Formation of electrochromic layer on first electrode-
In order to form an electrochromic layer on the first electrode, an oxidative coloring electrochromic composition having the following composition was prepared.
[composition]
・ The following oxidative coloring triarylamine compound: 50 parts

IRGACURE184 (manufactured by BASF Japan): 5 parts PEG400DA having bifunctional acrylate (manufactured by Nippon Kayaku): 50 parts Methyl ethyl ketone: 900 parts

The obtained oxidation coloring electrochromic composition was applied by spin coating on an ITO glass substrate (40 mm × 40 mm, thickness 0.7 mm, ITO film thickness: about 100 nm) as a first electrode. The obtained coating film was irradiated with UV at 10 mW for 60 seconds using a UV irradiation device (USHIO Corporation, SPOT CURE), annealed at 60 ° C. for 10 minutes, and crosslinked electro having an average thickness of 0.4 μm. A chromic layer was formed.

-Formation of counter electrode layer on second electrode-
An ITO glass substrate (40 mm × 40 mm, thickness 0.7 mm, ITO film thickness: about 100 nm) as a second electrode, a titanium oxide nanoparticle dispersion (trade name: SP210, manufactured by Showa Titanium Co., Ltd., average) as a deterioration preventing layer (Particle diameter: about 20 nm) was applied by spin coating and annealed at 120 ° C. for 15 minutes to form a 1.0 μm thick titanium oxide particle film.
Next, a composition containing 5 parts of the following compound 1 and 95 parts of methanol was prepared and applied onto the titanium oxide particle film by a spin coating method to form a counter electrode layer.
(Compound 1)

-Preparation of electrolyte-
An electrolyte solution having the following composition was prepared.
IRGACURE184 (manufactured by BASF Japan): 5 parts PEG400DA (manufactured by Nippon Kayaku Co., Ltd.): 100 parts 1-ethyl-3-methylimidazolium tetracyanoborate (manufactured by Merck) 50 parts

-Fabrication of electrochromic devices-
30 mg of the electrolyte solution was measured with a micropipette and dropped onto the ITO glass substrate having the counter electrode layer. On top of that, an ITO glass substrate having a cross-linked electrochromic layer was bonded so that there was a lead-out portion of the electrode, thereby preparing a bonded element.
This bonded element was irradiated with UV at 10 mW for 60 seconds using a UV (wavelength 250 nm) irradiation device (USHIO Corporation, SPOT CURE) to produce an electrochromic element.

<Driving voltage evaluation based on transmittance change and CV characteristics>
The color generation / decoloration of the produced electrochromic element was confirmed. Specifically, the measurement terminal was connected to the lead portion of the first electrode layer and the lead portion of the second electrode layer, and CV measurement was performed.
Electrical characteristics were measured at an insertion speed of -50 mV / sec. Furthermore, the average transmittance of 380 to 780 nm at that time is monitored using USB4000 (manufactured by Ocean Optics), and the color development voltage until the average transmittance reaches about 30% and the color erasing voltage until the color disappears. It was measured. As a result, the coloring voltage was -2.4V and the erasing voltage was + 0.3V.
The results of the current change (IV characteristic) with respect to the voltage at that time and the transmittance change (TV characteristic) with respect to the voltage are shown in FIGS. 2 and 3, respectively.

Comparative Example 1
A device was fabricated in the same manner as in Example 1 except that the spin coating of Compound 1 in “Formation of counter electrode layer on second electrode” in Example 1 was not performed and the titanium oxide particle film was used as it was. The coloring voltage and erasing voltage were determined in the same manner as in Example 1. As a result, the coloring voltage was -2.4V and the erasing voltage was + 2.0V.
The results of the current change with respect to the voltage (IV characteristics) and the transmittance change with respect to the voltage (TV characteristics) are shown in FIGS. 4 and 5, respectively.

Comparative Example 2
In place of the composition of Compound 1 in “Formation of counter electrode layer on second electrode” in Example 1, composition of 5 parts of decylphosphonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) shown below and 95 parts of methanol An electrochromic device was prepared in the same manner as in Example 1 except that a counter electrode layer was formed by applying a spin coating method on a titanium oxide particle film. With respect to this device, the CV characteristics were measured in the same manner as in Example 1 to determine the coloring voltage and the erasing voltage. However, no color was exhibited even when the voltage was applied to -5V. As a reference, FIG. 6 shows a current change (IV characteristic) with respect to voltage.

Example 2
Electrochromic was similarly performed except that the compound of [Chemical Formula 8] in “Formation of electrochromic layer on first electrode” in Example 1 was changed to the oxidative coloring electrochromic compound of [Chemical Formula 11] below. An element was produced. With respect to this device, the coloring voltage and the erasing voltage were determined in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 3
An electrochromic device was prepared in the same manner as in Example 2 except that the spin coating of Compound 1 in “Formation of counter electrode layer on second electrode” in Example 2 was not performed and the titanium oxide particle film was used as it was. Produced. With respect to this device, the coloring voltage and the erasing voltage were determined in the same manner as in Example 1. The results are shown in Table 1.

・メタノール：９５０部

得られた酸化発色性エレクトロクロミック組成物を、前記酸化チタン粒子膜に対してスピンコート法で塗布し、１２０℃で１０分間アニール処理を行って酸化チタン粒子膜上にエレクトロクロミック層を形成した。
次いで、このエレクトロクロミック層が形成された第１の電極層を用いた点以外は、実施例１と同様にしてエレクトロクロミック素子を作製し、実施例１と同様にして発色電圧と消色電圧を求めた。結果を表１に示す。 Example 3
The operation of “formation of electrochromic layer on first electrode” in Example 1 was changed as follows to form an electrochromic layer having an oxidative coloring triarylamine compound.

An ITO glass substrate (40 mm × 40 mm, average thickness 0.7 mm, ITO film thickness: about 100 nm) as a first electrode layer is coated with a titanium oxide nanoparticle dispersion (trade name: SP210, manufactured by Showa Titanium Co., Ltd., average particle diameter: About 20 nm) was applied by spin coating, and annealed at 120 ° C. for 15 minutes to form a titanium oxide particle film having a thickness of about 1.0 μm.
Next, an oxidative coloring electrochromic composition having the following composition to be supported on the titanium oxide particle film was prepared.
[composition]
・ The following oxidative coloring triarylamine compound: 50 parts

・ Methanol: 950 parts

The obtained oxidative coloring electrochromic composition was applied to the titanium oxide particle film by spin coating, and annealed at 120 ° C. for 10 minutes to form an electrochromic layer on the titanium oxide particle film.
Next, an electrochromic device is manufactured in the same manner as in Example 1 except that the first electrode layer on which this electrochromic layer is formed is used, and the coloring voltage and decoloring voltage are set in the same manner as in Example 1. Asked. The results are shown in Table 1.

Comparative Example 4
An electrochromic device was prepared in the same manner as in Example 3 except that the spin coating of Compound 1 in “Formation of counter electrode layer on second electrode” in Example 3 was not performed and the titanium oxide particle film was used as it was. Produced. With respect to this device, the coloring voltage and the erasing voltage were determined in the same manner as in Example 1. The results are shown in Table 1.

（上記式中、ｎは１８０〜１５０（ポリスチレン換算から推測）の整数を表す。）
・トルエン：９５０部

次いで、得られた酸化発色性エレクトロクロミック組成物を、ＩＴＯガラス基板（４０ｍｍ×４０ｍｍ、厚み０．７ｍｍ、ＩＴＯ膜厚：約１００ｎｍ）に対してスピンコート法で塗布し、１２０℃で１０分間乾燥処理を行って、エレクトロクロミック層を形成した。
このエレクトロクロミック層を用いた点以外は、実施例１と同様にしてエレクトロクロミック素子を作製した。この素子について、実施例１と同様にして発色電圧と消色電圧を求めた。結果を表１に示す。 Example 4
The operation of “formation of electrochromic layer on first electrode” in Example 1 was changed as follows to form an electrochromic layer having an oxidative coloring triarylamine polymer.
That is, first, an oxidative coloring electrochromic composition having the following composition was prepared.
[composition]
Oxidative coloring triarylamine polymer 103 represented by the following general formula 103: 50 parts

(In the above formula, n represents an integer of 180 to 150 (estimated from polystyrene conversion).)
-Toluene: 950 parts

Next, the obtained oxidative coloring electrochromic composition was applied to an ITO glass substrate (40 mm × 40 mm, thickness 0.7 mm, ITO film thickness: about 100 nm) by spin coating, and dried at 120 ° C. for 10 minutes. Processing was performed to form an electrochromic layer.
An electrochromic element was fabricated in the same manner as in Example 1 except that this electrochromic layer was used. With respect to this device, the coloring voltage and the erasing voltage were determined in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 5
An electrochromic device was prepared in the same manner as in Example 4 except that the spin coating of Compound 1 in “Formation of counter electrode layer on second electrode” in Example 4 was not performed and the titanium oxide particle film was used as it was. Produced. With respect to this device, the coloring voltage and the erasing voltage were determined in the same manner as in Example 1. The results are shown in Table 1.

As can be seen from Example 1 and Comparative Example 1 above, when the specific compound according to the present invention is added to the second electrode, the decoloring voltage is reduced and driving at a low voltage is possible compared to the case where the specific compound is not added. It becomes. Moreover, since the electrochromic behavior is not obtained in Comparative Example 2 using alkylphosphonic acid, it can be said that the effect is exhibited by the compound having a specific structure according to the present invention.
In addition, as can be seen from Table 1, by adding the specific compound of the present invention to the second electrode, an effect on low voltage can be obtained even for oxidative coloring electrochromic elements having different forms.

DESCRIPTION OF SYMBOLS 1 Support body 2 1st electrode 3 2nd electrode 4 Layer containing oxidation coloring electrochromic compound 5 Electrolyte layer 6 Specific compound of this invention 7 Counter electrode layer

Chem. Mater. 2006, 18, 5823-58259. Org. Electron. 2014, 15, 428-434.

Claims (7)

In an electrochromic device having a first electrode, a second electrode, and an electrolyte between the first electrode and the second electrode, a layer containing an oxidative coloring electrochromic compound is formed on the first electrode. And an electrochromic device comprising a layer containing a specific compound represented by the following general formula (1) on the second electrode.
General formula (1)

(In the above formula, R _{1 to} R ₅ each independently represent a hydrogen atom, a halogen atom, or a monovalent organic group, and at least one of R _{1 to} R ₅ is directly or indirectly to the hydroxyl group. It has a functional group that can be bound.)   The monovalent organic group in the specific compound is an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkoxy group, an aryloxy group, or a heteroaryloxy group. The electrochromic device described. _{3. The} electrochromic device according to claim 1, wherein R ₃ in the specific compound has a functional group capable of directly or indirectly bonding to a hydroxyl group.   The functional group that can be bonded directly or indirectly to the hydroxyl group is a phosphonic acid group, a phosphoric acid group, a carboxylic acid group, a sulfonyl group, a silyl group, or a silanol group. 4. The electrochromic device according to any one of 3.   The functional group capable of directly or indirectly binding to the hydroxyl group has an alkyl group, an aryl group, or an aryl group substituted with an alkyl group. Electrochromic element.   The electrochromic device according to claim 1, wherein the specific compound is bonded to or adsorbed to a conductive or semiconducting nanostructure provided on the second electrode.   The electrochromic according to any one of claims 1 to 5, wherein the layer containing the specific compound represented by the general formula (1) is a counter electrode layer provided on the second electrode. element.

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