JP2021026231A - Electrochromic element - Google Patents

Abstract

To provide an electrochromic element having high transparency in a discoloured state.SOLUTION: The electrochromic element includes: a first electrochromic layer 104 having a conductive or semiconductor nano structure and electrochromic compound on a first electrode 101; and an electrolyte layer 103 containing electrolyte between the first electrochromic layer 104 and a second electrode 102. The electrochromic compound is a compound represented by the following formula, anion of the electrolyte is monovalent anion with higher oxidation potential by 3.1 V or more than reduction potential of di-cation in the formula.SELECTED DRAWING: Figure 1

Description

The present invention relates to electrochromic devices.

The phenomenon in which a redox reaction occurs when a voltage is applied and the color changes is called electrochromism. The electrochromism is generally formed between two opposing electrodes and undergoes a redox reaction in a configuration in which an ionic conductive electrolyte layer is filled between the electrodes.

In such an electrochromic element, when trying to obtain a transparent display element, or when constructing an element having a configuration in which three color-developing layers of cyan (C), magenta (M), and yellow (Y) are laminated. In this case, it is important that the material is composed of a reduced electrochromic material having a transparent neutral state and an oxidized electrochromic material having a transparent neutral state. Further, for such a colorful display element, an organic electrochromic material capable of giving various colors by a substituent is suitable.

As the electrochromic material, a viologen derivative or the like showing an electrochromic phenomenon in which the neutral state is colorless and transparent and the color is developed in the reduced state is used. When the viologen derivative is used as the color-developing layer of the device, titanium oxide is preferably used. Among these, it has been reported that by using titanium oxide particles as the supporting particles of the electrochromic compound in the laminated structure, the viologen derivative can be layered at a very high concentration, so that a high optical concentration and a high contrast ratio can be realized. Has been done. Furthermore, by forming the viologen derivative as a solid layer, high responsiveness and memory properties can be obtained, which is a great advantage over an electrochromic device consisting of a layer using a liquid or gel in which the viologen derivative is dissolved in a solvent. There is.

As such an electrochromic device, for example, an electrochromic device using an electrochromic layer in which a viologen derivative is attached to a conductive or semiconductor nanostructure is disclosed (see, for example, Patent Document 1). In this device, the counter anions of the bromide derivative include Br ion (Br ⁻ ), Cl ion (Cl ⁻ ), I ion (I ⁻ ), OTf (triflate) ion (OTf ⁻ ), and ClO ₄ ion (ClO ₄ ⁻ ). , PF ₆ ion (PF ₆ ^-), and BF ₄ ion (BF ₄ ^-) are illustrated.
As yet another example, Patent Document 2 also discloses an electrochromic device. In this device, the counter anions of the bromide derivative are Br ion (Br ⁻ ), Cl ion (Cl ⁻ ), ClO ₄ ion (ClO ₄ −), PF ₆ ion (PF ₆ ⁻ ), and BF ₄ ion (BF ₄ ⁻ ). , TFSI ion (C ₂ F ₆ NO ₄ S ₂ ⁻ ), and FSI ion (CF ₃ SO ₃ ⁻ ) are exemplified.
These counter anions are not particularly limited, ^{and Br −} and Cl ⁻ are only described as specific examples. In addition, these documents make no mention of how the various properties of the device change depending on the type of counter anion.

On the other hand, many devices using a solution or gel in which a viologen derivative is dissolved in a solvent are also disclosed. For example, Patent Document 3 discloses an element in which a viologen derivative is dissolved in a solvent, gelled, and then laminated. In addition, Patent Document 4 discloses a configuration in which a solution of a viologen derivative is sandwiched between electrodes. Further, as a viologen derivative used in a solution system, for example, Patent Document 5 discloses an aryl viologen derivative. However, the number of specific anions of the viologen derivative in these devices or materials is not necessarily limited, and the difference in characteristics depending on the type of anion is not described at all. The point that some specific anions are presented is selected only from the viewpoint of being inactive to the redox reaction in the device, for example, as specified in Patent Document 6.

An object of the present invention is to provide an electrochromic device having high transparency in a decolorized state.

An electrochromic device as an example of means for solving the above problems has, for example, the following configuration.
With the first electrode
A second electrode provided so as to face the first electrode at a distance,
On the first electrode, a first electrochromic layer having a conductive or semiconductor nanostructure and an electrochromic compound,
It has an electrolyte layer between the first electrochromic layer and the second electrode.
The electrochromic compound is a compound represented by the following general formula 1.
The electrochromic device is characterized in that the anion of the electrolyte is a monovalent anion having an oxidation potential higher than the reduction potential of the dication in the general formula 1 by 3.1 V or more.
[General formula 1]
In the general formula 1, R ₁ and R ₂ are hydrogen atom, aryl group up to 14 carbon atoms, heteroaryl group up to 14 carbon atoms, branched alkyl group up to 10 carbon atoms, and carbon atom, respectively. Represents an alkenyl group up to several tens, a cycloalkyl group up to ten carbon atoms, or a functional group that can be bonded to a hydroxyl group. R ₃ and R ₄ represent an arylene group having up to 12 carbon atoms which may have an alkylene group having 1 to 10 carbon atoms or a substituent.
In the general formula 1, Z is alkylene, cycloalkylene, and R _7- Y-R ₈ (where R ₇ and R ₈ are independently selected from single bond, alkylene, and cycloalkylene, respectively. Y is selected from arylene, cycloalkylene, heteroarylene, arylene-allylen, and arylene-CR'R''-arylene, where R'and R'' are combined with the carbon to which they are attached. It is selected from divalent groups (forming carbon ring groups). The alkylene, the cycloalkylene, the arylene, the heteroarylene, and the carbocyclic group are halogen, alkyl, alkoxy, alkylthio, hydroxyalkyl, acyloxy, cycloalkyl, aryl, substituted aryl, aryloxy, heteroaryl and Substituted Heteroaryls may be substituted with one or more substituents selected from them. k represents 0 or 1.
In the general formula 1, X ⁻ represents a monovalent anion having an oxidation potential higher than the reduction potential of the dication in the general formula 1 by 3.1 V or more.
In the general formula 1, W ²⁺ represents a dication represented by the following general formula 2.
[General formula 2]
In the general formula 2, o, p, and q each independently represent 0 or 1, and A, B, and C each independently may have a substituent and have 2 to 20 carbon atoms. Represents a group or a heterocyclic group.

An electrochromic device as another example of means for solving the above problems has, for example, the following configuration.
With the first electrode
A second electrode provided so as to face the first electrode at a distance,
A first electrochromic layer obtained by adhering an electrochromic compound to a conductive or semiconductor nanostructure on the first electrode, and
It has an electrolyte layer between the first electrochromic layer and the second electrode.
An electrochromic device characterized in that the electrochromic compound is a compound represented by the following general formula 1.
[General formula 1]
In the general formula 1, R ₁ and R ₂ are hydrogen atom, aryl group up to 14 carbon atoms, heteroaryl group up to 14 carbon atoms, branched alkyl group up to 10 carbon atoms, and carbon atom, respectively. Represents an alkenyl group up to several tens, a cycloalkyl group up to ten carbon atoms, or a functional group that can be bonded to a hydroxyl group. R ₃ and R ₄ represent an arylene group having up to 12 carbon atoms which may have an alkylene group having 1 to 10 carbon atoms or a substituent.
In the general formula 1, Z is alkylene, cycloalkylene, and R _7- Y-R ₈ (where R ₇ and R ₈ are independently selected from single bond, alkylene, and cycloalkylene, respectively. Y is selected from arylene, cycloalkylene, heteroarylene, arylene-allylen, and arylene-CR'R''-arylene, where R'and R'' are combined with the carbon to which they are attached. It is selected from divalent groups (forming carbon ring groups). The alkylene, the cycloalkylene, the arylene, the heteroarylene, and the carbocyclic group are halogen, alkyl, alkoxy, alkylthio, hydroxyalkyl, acyloxy, cycloalkyl, aryl, substituted aryl, aryloxy, heteroaryl and Substituted Heteroaryls may be substituted with one or more substituents selected from them. k represents 0 or 1.
In the general formula 1, X ⁻ represents a monovalent anion having an oxidation potential higher than the reduction potential of the dication in the general formula 1 by 3.1 V or more.
In the general formula 1, W ²⁺ represents a dication represented by the following general formula 2.
[General formula 2]
In the general formula 2, o, p, and q each independently represent 0 or 1, and A, B, and C each independently may have a substituent and have 2 to 20 carbon atoms. Represents a group or a heterocyclic group.

According to the present invention, it is possible to provide an electrochromic device having high transparency in a decolorized state.

FIG. 1 is a schematic view showing a configuration example of the electrochromic device of the present invention.

The reason why the anion of the viologen derivative can be used in the solution system without being particularly affected by the type is that in such a solution system, the viologen derivative does not actually exist in the state of a complex or an ion pair, and is used as a solvent. It is mentioned that it is dissolved and ion-dissociated and exists as a solvated free cation. Therefore, it behaves the same as a viologen derivative cation without being affected by what the original type of counter ion was. Even if it is affected by free anions that are relatively close to each other, a much larger amount of electrolyte is usually added to these solution systems than the viologen derivative, and the influence of the anions on this electrolyte becomes dominant. After all, it is almost unaffected by what the original type of counterion was.

On the other hand, in an environment where the viologen derivative exists as an ion pair or a complex, there is almost no solvent or other ions between the viologen derivative molecules, and the viologen derivative is present at a very high concentration, the viologen derivative is used. The properties are strongly influenced by the type of counter anion. Such an environment is a case where the viologen derivative is used in a solid state or in a state of being supported on a carrier, and more specifically, an electro-electron in which the viologen derivative is attached to a conductive or semiconductor nanostructure. The case of an electrochromic element using a chromic layer is one of the typical examples. Therefore, it is a problem peculiar to an electrochromic device using an electrochromic layer having a viologen derivative and a conductive or semiconducting nanostructure that the characteristics of the device change greatly depending on the type of counter anion of the viologen derivative. The present inventors have found.

However, as described above, the influence of the type of counter anion in such an electrochromic device has not been sufficiently studied so far.

Therefore, the present inventor presents a counter for a dication of an electrochromic device having an electrochromic layer having a specific dication (compound represented by the following general formula A) such as a viologen derivative and a conductive or semiconductor nanostructure. As a result of diligent studies on the types of anions, it was found that the transparency of the decolorized device differs depending on the type of counter anion.
[General formula 1]
In the general formula 1, R ₁ and R ₂ are hydrogen atom, aryl group having up to 14 carbon atoms, heteroaryl group having up to 14 carbon atoms, branched alkyl group having up to 10 carbon atoms, and 10 carbon atoms, respectively. Represents an alkenyl group up to, or a functional group capable of bonding to a cycloalkyl group or a hydroxyl group having up to 10 carbon atoms. R ₃ and R ₄ represent an arylene group having up to 12 carbon atoms which may have an alkylene group having 1 to 10 carbon atoms or a substituent.
In the general formula 1, Z is alkylene, cycloalkylene, and R _7- Y-R ₈ (where R ₇ and R ₈ are independently selected from single bond, alkylene, and cycloalkylene, respectively. Y is selected from arylene, cycloalkylene, heteroarylene, arylene-allylen, and arylene-CR'R''-arylene, where R'and R'' are combined with the carbon to which they are attached. It is selected from divalent groups (forming carbon ring groups). The alkylene, the cycloalkylene, the arylene, the heteroarylene, and the carbocyclic group are halogen, alkyl, alkoxy, alkylthio, hydroxyalkyl, acyloxy, cycloalkyl, aryl, substituted aryl, aryloxy, heteroaryl and Substituted Heteroaryls may be substituted with one or more substituents selected from them. k represents 0 or 1.
In the general formula 1, X ⁻ represents an ion that neutralizes the charge.
In the general formula 1, W ²⁺ represents a dication represented by the following general formula 2.
[General formula 2]
In the general formula 2, o, p, and q each independently represent 0 or 1, and A, B, and C each independently may have a substituent and have 2 to 20 carbon atoms. Represents a group or a heterocyclic group.
As a result of further studies, a monovalent anion having an oxidation potential higher than the reduction potential of the dication in the general formula 1 by 3.1 V or more is used as the anion of the specific dication, thereby decolorizing. It was found that it has high transparency in the above, and the present invention was completed.

In the present invention, having high transparency in the decolorized state means that the first electrochromic layer has a low YI (yellow index) value. That is, even if the YI value of the element itself is high due to coloring of the electrodes or the like, if the YI value of the first electrochromic layer is kept low, it corresponds to having high transparency in the decolorized state.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

(Electrochromic element)
FIG. 1 shows a configuration example of the electrochromic device of the present invention. The electrochromic device has a first electrode 101, a second electrode 102, an electrolyte layer 103, a first electrochromic layer 104, and a second electrochromic layer 105.

The electrochromic device of the present invention includes, for example, the following first and second aspects.

<First aspect>
The first aspect of the electrochromic device of the present invention is
With the first electrode
A second electrode provided so as to face the first electrode at a distance,
A first electrochromic layer obtained by adhering an electrochromic compound to a conductive or semiconductor nanostructure on the first electrode, and
It has an electrolyte layer between the first electrochromic layer and the second electrode.
The electrochromic compound is a compound represented by the following general formula 1.
[General formula 1]
In the general formula 1, R ₁ and R ₂ are hydrogen atom, aryl group having up to 14 carbon atoms, heteroaryl group having up to 14 carbon atoms, branched alkyl group having up to 10 carbon atoms, and 10 carbon atoms, respectively. Represents an alkenyl group up to, or a functional group capable of bonding to a cycloalkyl group or a hydroxyl group having up to 10 carbon atoms. R ₃ and R ₄ represent an arylene group having up to 12 carbon atoms which may have an alkylene group having 1 to 10 carbon atoms or a substituent.
In the general formula 1, Z is alkylene, cycloalkylene, and R _7- Y-R ₈ (where R ₇ and R ₈ are independently selected from single bond, alkylene, and cycloalkylene, respectively. Y is selected from arylene, cycloalkylene, heteroarylene, arylene-allylen, and arylene-CR'R''-arylene, where R'and R'' are combined with the carbon to which they are attached. It is selected from divalent groups (forming carbon ring groups). The alkylene, the cycloalkylene, the arylene, the heteroarylene, and the carbocyclic group are halogen, alkyl, alkoxy, alkylthio, hydroxyalkyl, acyloxy, cycloalkyl, aryl, substituted aryl, aryloxy, heteroaryl and Substituted Heteroaryls may be substituted with one or more substituents selected from them. k represents 0 or 1.
In the general formula 1, X ⁻ is a monovalent anion having an oxidation potential higher than the reduction potential of the dication in the general formula 1 by 3.1 V or more (hereinafter, may be referred to as “high oxidation potential anion”). Is shown.
In the general formula 1, W ²⁺ represents a dication represented by the following general formula 2.
[General formula 2]
In the general formula 2, o, p, and q each independently represent 0 or 1, and A, B, and C each independently may have a substituent and have 2 to 20 carbon atoms. Represents a group or a heterocyclic group.

An important point in the first aspect is that the first electrochromic layer is obtained by adhering the electrochromic compound to a conductive or semiconductor nanostructure. That is, when the electrochromic compound is attached to a conductive or semiconductor nanostructure to form the first electrochromic layer, the high oxidation potential anion is used as the anion of the electrochromic compound.
Comparing the examples of the present specification with the comparative examples, in the examples, the compound of the general formula 1 is used when forming the first electrochromic layer. On the other hand, in the comparative example, when forming the first electrochromic layer, the oxidation potential is not higher than the reduction potential of the dication in the general formula 1 by 3.1 V or more instead of the anion of the compound of the general formula 1. A monovalent anion having (Br ⁻ , Cl ⁻ : hereinafter, may be referred to as “low oxidation potential anion”) is used.
In the electrochromic device of the embodiment of the present specification, a low YI value is obtained at the time of manufacturing the device due to the high oxidation potential anion, and this state is maintained for a long time.
On the other hand, in the electrochromic device of the comparative example of the present specification, due to the low oxidation potential anion, a high YI value is obtained at the time of manufacturing the device, and this state is maintained for a long time.
Here, in general, the anion in the electrolyte layer and the anion in the first electrochromic layer are ion-exchanged after the electrochromic device is manufactured. The degree of ion exchange is not clear, but ion exchange of about 50% or more is expected. Therefore, the anions contained in the electrolyte layer at the time of device fabrication are ion-exchanged with the anions contained in the first electrochromic layer at the time of device fabrication to some extent, and even in the electrochromic device of the comparative example of the present specification, the device After production, the anions contained in the electrolyte layer will be contained in the first electrochromic layer. Then, once ion exchange occurs, it is almost impossible to obtain the amount of ion-exchanged anions only from the device after ion exchange. That is, after ion exchange occurs, each of the anion contained in the first electrochromic layer of the device after ion exchange and the anion contained in the electrolyte layer form the first electrochromic layer at the time of device fabrication. This is because it cannot be confirmed by analysis whether it is the anion used for the purpose or the anion used for forming the electrolyte layer.
In the electrochromic device of the comparative example of the present specification, the high oxidation potential anion is used in order to form an electrolyte layer at the time of manufacturing the device. In this case, when ion exchange occurs, the high oxidation potential anion is present in the first electrochromic layer of the device of the comparative example after ion exchange, but even in that case, the YI value of the example and Holds a state of YI value high enough to be distinguished.
Therefore, in both the examples and the comparative examples of the present specification, although there are states having the high oxidation potential anion in the first electrochromic layer after the device is manufactured, the examples and the comparative examples in those states are different. , YI values are clearly different. However, in both the examples and comparative examples of the present specification, in a state where ion exchange occurs after device fabrication and the high oxidation potential anion is present in the first electrochromic layer, it is not possible to distinguish these states by analysis. It is impossible or impractical in a small electrochromic device having a thick electrolyte layer as compared with the thickness of the first electrochromic layer and the first electrochromic layer of the thin film. What is impossible or impractical is that, for example, it is impossible to analyze the difference between the following two elements (the first element and the second element) after the elements are manufactured and after ion exchange. It is clear from that.
First device: At the time of device fabrication, 1 unit of the high oxidation potential anion was used to form the first electrochromic layer, and a mixture of the high potential anion and the low oxidation potential anion (50 units) was used to form the electrolyte layer. : An element using a mixture of 50 units).
Second element: At the time of device fabrication, 1 unit of the low oxidation potential anion was used to form the first electrochromic layer, and a mixture of the high potential anion and the low oxidation potential anion (49 units) was used to form the electrolyte layer. : 51 units of mixture).
In the first element and the second element, after ion exchange of about 50% or more of the anion of the first electrochromic layer is performed between the first electrochromic layer and the electrolyte layer, the first device is used. It is no longer possible to distinguish by analysis the difference in the amount of the high oxidation potential anion and the low oxidation potential anion present in the first electrochromic layer and the electrolyte layer, respectively, between the device and the second device.
Therefore, an important point in the first aspect is that the first electrochromic layer is obtained by adhering the electrochromic compound to a conductive or semiconductor nanostructure. That is, when the electrochromic compound is attached to a conductive or semiconductor nanostructure to form the first electrochromic layer, the high oxidation potential anion is used as the anion of the electrochromic compound. This point is particularly important under conditions that do not limit the anions used to form the electrolyte layer.

<Second aspect>
A second aspect of the electrochromic device of the present invention is
With the first electrode
A second electrode provided so as to face the first electrode at a distance,
On the first electrode, a first electrochromic layer having a conductive or semiconductor nanostructure and an electrochromic compound,
An electrolyte layer containing an electrolyte is provided between the first electrochromic layer and the second electrode.
The electrochromic compound is a compound represented by the following general formula 1.
The electrolyte anion is a monovalent anion having an oxidation potential that is 3.1 V or more higher than the reduction potential of the dication in the general formula 1.
[General formula 1]
In the general formula 1, R ₁ and R ₂ are hydrogen atom, aryl group having up to 14 carbon atoms, heteroaryl group having up to 14 carbon atoms, branched alkyl group having up to 10 carbon atoms, and 10 carbon atoms, respectively. Represents an alkenyl group up to, or a functional group capable of bonding to a cycloalkyl group or a hydroxyl group having up to 10 carbon atoms. R ₃ and R ₄ represent an arylene group having up to 12 carbon atoms which may have an alkylene group having 1 to 10 carbon atoms or a substituent.
In the general formula 1, Z is alkylene, cycloalkylene, and R _7- Y-R ₈ (where R ₇ and R ₈ are independently selected from single bond, alkylene, and cycloalkylene, respectively. Y is selected from arylene, cycloalkylene, heteroarylene, arylene-allylen, and arylene-CR'R''-arylene, where R'and R'' are combined with the carbon to which they are attached. It is selected from divalent groups (forming carbon ring groups). The alkylene, the cycloalkylene, the arylene, the heteroarylene, and the carbocyclic group are halogen, alkyl, alkoxy, alkylthio, hydroxyalkyl, acyloxy, cycloalkyl, aryl, substituted aryl, aryloxy, heteroaryl and Substituted Heteroaryls may be substituted with one or more substituents selected from them. k represents 0 or 1.
In the general formula 1, X ⁻ represents a monovalent anion having an oxidation potential higher than the reduction potential of the dication in the general formula 1 by 3.1 V or more.
In the general formula 1, W ²⁺ represents a dication represented by the following general formula 2.
[General formula 2]
In the general formula 2, o, p, and q each independently represent 0 or 1, and A, B, and C each independently may have a substituent and have 2 to 20 carbon atoms. Represents a group or a heterocyclic group.

In the second aspect, a device having more excellent transparency can be obtained even when the anion of the electrochromic compound and the anion of the electrolyte are ion-exchanged in the device.

In a second aspect, the first electrochromic layer has conductive or semiconducting nanostructures and electrochromic compounds on the first electrode.
Here, in the second aspect, the first electrochromic layer is not particularly limited as long as it has a conductive or semi-conductive nanostructure and the above-mentioned electrochromic compound, depending on the intended purpose. It can be selected as appropriate. The first electrochromic layer is preferably one in which an electrochromic compound is attached to a conductive or semiconductor nanostructure. In other words, in the second aspect, the first electrochromic layer is preferably one in which an electrochromic compound is attached to a conductive or semiconductor nanostructure.

The important points in the second aspect are the following two points.
(I) The electrochromic compound in the first electrochromic layer is a compound represented by the general formula 1.
(Ii) The anion of the electrolyte in the electrolyte layer containing the electrolyte is a monovalent anion having an oxidation potential that is 3.1 V or more higher than the reduction potential of the dication in the general formula 1.

In the first aspect, when the electrochromic compound is attached to a conductive or semiconductor nanostructure to form a first electrochromic layer, the high oxidation potential anion is used as the anion of the electrochromic compound. This is very important. It is particularly important under conditions that do not limit the anion used to form the electrolyte layer.
On the other hand, in the second aspect, in addition to the electrochromic compound in the first electrochromic layer being the compound represented by the general formula 1, the anion in the electrolyte of the electrolyte layer is the high oxidation potential anion. In this case, since the anions existing in the first electrochromic layer and the electrolyte layer are substantially only the high oxidation potential anions, they are present in the first electrochromic layer and the electrolyte layer even if those anions are ion-exchanged. The state of the high oxidation potential anion is almost unchanged.
Regarding the second aspect, the electrochromic compound in the first electrochromic layer is a compound represented by the general formula 1, and the anion of the electrolyte is based on the reduction potential of the dication in the general formula 1. The monovalent anion having an oxidation potential higher than 3.1 V may be before the anion exchange between the first electrochromic layer and the electrolyte layer is performed, or the anion exchange is performed. It may be after.
In the second aspect, the electrolyte layer may contain a trace amount of the low oxidation potential anion of about 10 mol% of the total amount of anions. Moreover, in the first electrochromic layer, the low oxidation potential anion of about 10 mol% of the total amount of anions may be contained.

<First electrochromic layer>
In the first aspect, the first electrochromic layer is obtained by attaching an electrochromic compound to a conductive or semiconducting nanostructure.
In a second aspect, the first electrochromic layer comprises a conductive or semiconducting nanostructure and an electrochromic compound. Further, in the second aspect, it is preferable that the first electrochromic layer is obtained by adhering an electrochromic compound to the nanostructure.

In the present invention, adhesion means, for example, a state of being chemically bonded by a covalent bond or an ionic bond, a state of being physically adsorbed by a hydrogen bond or an intermolecular force, and a state of physically depositing particles or amorphous solids. However, it is not limited to these.

As a method for forming the first electrochromic layer, for example, a vacuum deposition method, a sputtering method, an ion plating method and the like can be used. Further, as long as the material of the first electrochromic layer can be applied and formed, for example, a spin coating method, a casting method, a microgravure coating method, a gravure coating method, a bar coating method, a roll coating method, and a wire bar coating method. , Dip coating method, slit coating method, capillary coating method, spray coating method, nozzle coating method, gravure printing method, screen printing method, flexographic printing method, offset printing method, reverse printing method, inkjet printing method, etc. Can be used.
For example, if the first electrochromic layer is formed by the method shown in the examples of the present specification, the first electrochromic layer is formed by adhering an electrochromic compound to a conductive or semiconductor nanostructure. Can be produced.

The average thickness of the first electrochromic layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.2 μm or more and 5.0 μm or less. When the average thickness is 0.2 μm or more, a deep color development density is likely to be obtained, and when it is 5.0 μm or less, the manufacturing cost is suppressed, and the visibility is less likely to be deteriorated due to coloring. Although the first electrochromic layer can be formed by vacuum film formation, it is preferably formed by coating as a particle dispersion paste from the viewpoint of productivity.

The first electrochromic layer is laminated on the first electrode, and only one layer may be laminated, or two or more layers may be laminated.

After forming the conductive or semiconductor nanostructures, the electrochromic compound may be attached. At this time, the method for forming the conductive or semiconductor nanostructure can be the same as the method for forming the first electrochromic layer. As the method for adhering the electrochromic compound, for example, a vacuum deposition method, a sputtering method, an ion plating method or the like can be used. In addition, spin coating method, casting method, microgravure coating method, gravure coating method, bar coating method, roll coating method, wire bar coating method, dip coating method, slit coating method, capillary coating method, spray coating method, nozzle coating method. , Gravure printing method, screen printing method, flexo printing method, offset printing method, reverse printing method, inkjet printing method and various other printing methods can be used.

<< Conductive or semiconductor nanostructures >>

The conductive or semiconductor nanostructure according to the present invention is a structure having nanoscale irregularities such as nanoparticles or nanoporous structures.

As the material constituting the conductive or semiconductor nanostructure, a metal oxide is preferable from the viewpoint of transparency and conductivity. Examples of such metal oxides are titanium oxide, zinc oxide, tin oxide, zirconium oxide, cerium oxide, yttrium oxide, boron oxide, magnesium oxide, strontium titanate, potassium titanate, barium titanate, calcium titanate. , Calcium oxide, ferrite, hafnium oxide, tungsten oxide, iron oxide, copper oxide, nickel oxide, cobalt oxide, barium oxide, strontium oxide, vanadium oxide, aluminosilicate, calcium phosphate, aluminosilicate, etc. Used. Further, these metal oxides may be used alone or in combination of two or more.

From metal oxides such as titanium oxide, zinc oxide, tin oxide, zirconium oxide, iron oxide, magnesium oxide, indium oxide, tungsten oxide, etc., in consideration of electrical properties such as electrical conductivity and physical properties such as optical properties. When one of the selected materials or a mixture thereof is used, the response speed of color development is excellent. In particular, when titanium oxide is used, the response speed of color development is more excellent.

The shape of the metal oxide is preferably metal oxide fine particles having an average primary particle diameter of 30 nm or less. The smaller the particle size, the higher the transmittance of light to the metal oxide, and the larger the surface area per unit volume (hereinafter referred to as "specific surface area") is used. By having a large specific surface area, the electrochromic compound is supported more efficiently, and multicolor display with an excellent display contrast ratio of color emission / extinction is possible. The specific surface area of the nanostructure is not particularly limited, ^{but can be, for example, 100 m 2} / g or more.

<< Electrochromic compound >>
The electrochromic compound of the present invention is a compound represented by the following general formula 1.
[General formula 1]
In the general formula 1, R ₁ and R ₂ are hydrogen atom, aryl group having up to 14 carbon atoms, heteroaryl group having up to 14 carbon atoms, branched alkyl group having up to 10 carbon atoms, and 10 carbon atoms, respectively. Represents an alkenyl group up to, or a functional group capable of bonding to a cycloalkyl group or a hydroxyl group having up to 10 carbon atoms. R ₃ and R ₄ represent an arylene group having up to 12 carbon atoms which may have an alkylene group having 1 to 10 carbon atoms or a substituent.
In the general formula 1, Z is alkylene, cycloalkylene, and R _7- Y-R ₈ (where R ₇ and R ₈ are independently selected from single bond, alkylene, and cycloalkylene, respectively. Y is selected from arylene, cycloalkylene, heteroarylene, arylene-allylen, and arylene-CR'R''-arylene, where R'and R'' are combined with the carbon to which they are attached. It is selected from divalent groups (forming carbon ring groups). The alkylene, the cycloalkylene, the arylene, the heteroarylene, and the carbocyclic group are halogen, alkyl, alkoxy, alkylthio, hydroxyalkyl, acyloxy, cycloalkyl, aryl, substituted aryl, aryloxy, heteroaryl and Substituted Heteroaryls may be substituted with one or more substituents selected from them. k represents 0 or 1.
In the general formula 1, X ⁻ represents a monovalent anion having an oxidation potential higher than the reduction potential of the dication in the general formula 1 by 3.1 V or more.
In the general formula 1, W ²⁺ represents a dication represented by the following general formula 2.
[General formula 2]
In the general formula 2, o, p, and q each independently represent 0 or 1, and A, B, and C each independently may have a substituent and have 2 to 20 carbon atoms. Represents a group or a heterocyclic group.

In the general formula 1, W ²⁺ expresses an electrochromic function, and the color is changed by redoxing this portion. _{R 1, R 2, R 3} , R 4 and Z does not contribute to the electrochromic function, and does not even inhibit electrochromic functionality ^{W 2+.}

A more preferred form is a functional group to which at least one of _{R 1} or R _{2 can be attached to a hydroxyl group.} This makes it possible to easily adhere to the conductive or semiconductor nanostructures.
A more preferred form is a _{functional group in which both R 1} and R ₂ can be attached to the hydroxyl group. By doing so, the coupling becomes stronger, the possibility of desorption in the element is reduced, and the reliability is improved.
Another preferred form is a _{functional group to which either R 1} or R ₂ can be attached to the hydroxyl group. By doing so, more electrochromic compounds can be attached to the conductive or semi-conductive nanostructures, leading to an improvement in color density.

Examples of the functional group that can be bonded to the hydroxyl group include a phosphonic acid group, a phosphoric acid group, a carboxylic acid group, a sulfonyl group, a silyl group, and a silanol group. Among these, a phosphonic acid group, a phosphoric acid group, and a carboxylic acid group are preferable, and a phosphonic acid group is more preferable, from the viewpoint of ease of synthesis, adsorptivity to supporting particles, and stability of the compound.
Examples of the silyl group include the following alkoxysilyl groups.
−SiR ¹⁰⁰ _n (OR ¹⁰¹ ) _3-n
In the above formula, R ¹⁰⁰ represents an alkyl group having 1 to 4 carbon atoms. R ¹⁰¹ represents an alkoxy group having 1 to 4 carbon atoms. n represents an integer of 0 to 2. When R ¹⁰⁰ is 2 or more, they may be the same or different. When OR ¹⁰¹ is 2 or more, they may be the same or different.

As described above, in the present invention, for example, _{at least one of R 1} and R ₂ in the general formula 1 is any of a phosphonic acid group, a phosphoric acid group, a carboxylic acid group, a sulfonyl group, a silyl group, and a silanol group. It is preferable that it is. By doing so, it becomes possible to easily adhere to the conductive or semiconductor nanostructure.
In this case, in the present invention, for example, in the general formula 1, R ₁ and R ₂ ( _{both R 1} and R ₂ ) are a phosphonic acid group, a phosphoric acid group, a carboxylic acid group, a sulfonyl group, a silyl group, and If any of the silanol groups is used, the bond becomes stronger, the possibility of desorption in the element is reduced, and the reliability can be improved.
Further, in the present invention, in the general formula 1, _{either R 1} or R ₂ is any one of a phosphonic acid group, a phosphoric acid group, a carboxylic acid group, a sulfonyl group, a silyl group, and a silanol group. On the other hand, hydrogen atoms, aryl groups with up to 14 carbon atoms, heteroaryl groups with up to 14 carbon atoms, branched alkyl groups with up to 10 carbon atoms, alkenyl groups with up to 10 carbon atoms, and up to 10 carbon atoms. When any of the cycloalkyl groups of the above, more electrochromic compounds can be attached to the conductive or semi-conductive nanostructure, and the color development density can be improved.

When having a phosphonic acid, a phosphoric acid group, a carboxyl group, a sulfonyl group or the like as a functional group, the electrochromic compound adheres to the nanostructure more easily. Further, when the electrochromic compound has a silyl group, silanol group or the like, it adheres to the nanostructure via a siloxane bond and the bond becomes strong, so that a stable electrochromic layer can be obtained. The siloxane bond refers to a chemical bond via a silicon atom and an oxygen atom.

Examples of the phosphonic acid group include methylphosphonic acid group, ethylphosphonic acid group, propylphosphonic acid group, hexylphosphonic acid group, octylphosphonic acid group, decylphosphonic acid group, dodecylphosphonic acid group, octadecylphosphonic acid group, and benzylphosphonate. Examples thereof include an acid group, a phenylethylphosphonic acid group, a phenylpropylphosphonic acid group, and a biphenylphosphonic acid group. Examples of the phosphate group include methyl phosphate group, ethyl phosphate group, propyl phosphate group, hexyl phosphate group, octyl phosphate group, decyl phosphate group, dodecyl phosphate group, octadecyl phosphate group, benzyl phosphate group and phenyl. Examples thereof include an ethyl phosphate group, a phenylpropyl phosphate group, and a biphenyl phosphate group. Examples of the carboxylic acid group include methylcarboxylic acid group, ethylcarboxylic acid group, propylcarboxylic acid group, hexylcarboxylic acid group, octylcarboxylic acid group, decylcarboxylic acid group, dodecylcarboxylic acid group, octadecylcarboxylic acid group, and benzyl. Examples thereof include a carboxylic acid group, a phenylethyl carboxylic acid group, a phenylpropyl carboxylic acid group, a biphenyl carboxylic acid group, a 4-propyl phenyl carboxylic acid group, and a 4-propyl biphenyl carboxylic acid group.

Examples of the sulfonyl group include methyl sulfonyl group, ethyl sulfonyl group, propyl sulfonyl group, hexyl sulfonyl group, octyl sulfonyl group, decyl sulfonyl group, dodecyl sulfonyl group, octadecyl sulfonyl group, benzyl sulfonyl group, phenyl ethyl sulfonyl group and phenyl propi. Examples thereof include a rusulfonyl group and a biphenylsulfonyl group. Examples of the silyl group include methylsilyl group, ethylsilyl group, propylsilyl group, hexylsilyl group, octylsilyl group, decylsilyl group, dodecylsilyl group, octadecylsilyl group, benzylsilyl group, phenylethylsilyl group and phenylpropylsilyl group. , Biphenylsilyl group and the like. Examples of the silanol group include methylsilanol group, ethylsilanol group, propylsilanol group, hexylsilanol group, octylsilanol group, decylsilanol group, dodecylsilanol group, octadecylsilanol group, benzylsilanol group, phenylethylsilanol group and phenylpropi. Examples thereof include a lucilanol group and a biphenylsilanol group.

In the general formula 1, Z is C1 to C12 alkylene, C3 to C7 cycloalkylene, C3 to C14 arylene, C5 to C10 heteroarylene, (C1 to C4 alkylene)-(C3 to C14 arylene), (C1 to C4 alkylene). )-(C3-C14 heteroarylene), (C1-C4alkylene)-(C3-C14 arylene)-(C1-C4alkylene), (C1-C4alkylene)-(C3-C14 heteroarylene)-(C1-C4) (Alkylene), (C3 to C14 allele)-(C3 to C14 allele), (C1 to C4 alkylene)-(C3 to C14 allele)-(C3 to C14 allele)-(C1 to C4 alkylene), and (C3 to C14). It is preferred to be selected from (arylene)-(CR'R'')-(C3 to C14 arylene), where R'and R'' form a C3 to C20 carbon ring group with the carbon to which they are attached. Formed; arylene and cycloalkylene groups may be substituted with one or more substituents selected from halogen, C1-C4 alkyl, C1-C4 alkoxy and C3-C7 cycloalkyl, where the alkylene group is halogen. , C3-C14 alkyl, C1-C12 alkoxy, C2-C12 acyloxy, C1-C12 hydroxyalkyl, C3-C12 cycloalkyl, phenyl, phenyloxy and substituted with one or more substituents selected from substituted phenyl. May be good. Specifically, the substituted alkylene contains −CH2 (CRaRb) CH2-, and Ra and Rb independently H, C3-C14 alkyl, C3-C12 cycloalkyl, (cycloalkyl) methyl, aryl, substituted aryl. , Arylalkyl (eg, benzyl or phenyl (C2-C7alkyl), etc.), phenyloxyethyl, substituted arylalkyl, C1-C12 alkoxy, C2-C12 acyloxy, C1-C12 hydroxyalkyl, and C1-C12 alkoxymethyl. May be done.

Z is C1 to C12 alkylene, aryl substituted C1 to C12 alkylene, phenylene, naphthylene, (C1 to C4 alkylene) -phenylene- (C1 to C4 alkylene), (C1 to C4 alkylene) -naphthylene- (C1 to C4 alkylene). ) (For example, naphthylenebis (methylene), etc.), Kinoxalin-2,3-diyl, (C1-C4alkylene) -quinoxalin-2,3-diyl- (C1-C4alkylene) (for example, quinoxalin-2,3-diylbis) (Methylene) and the like), phenylene-phenylene, (C1-C4alkylene) -phenylene-phenylene- (C1-C4alkylene) and phenylene-fluorenylene-phenylene are more preferably selected.
As Z, for example, −CH ₂ −, − (CH ₂ ) ₂ −, − (CH ₂ ) ₃ −, − (CH ₂ ) ₄ −, − (CH ₂ ) ₅ −, _{−CH 2} −CH (CH) _{3) -CH 2 -, - CH} 2 -CH (CH 2 _{phenyl) -CH 2 -, - (CH} 2) 2 -CH (CH 3) -CH 2 -, - (CH 2) 3 -CH (CH 3 ) -CH ₂ -,-(CH ₂ ) _2- CH (CH ₃ )-(CH ₂ ) _2- , and the like.

Further, as Z in the general formula 1, those represented by the following structural formula can be preferably used.

In the general formula 1, ^{the oxidation potential of X −} is 3.1 V or more higher than the reduction potential of the dication in the general formula 1. In other words, X ⁻ represents a monovalent anion having an oxidation potential that is 3.1 V or more higher than the reduction potential of the dication in the general formula 1. If ^{the oxidation potential of X −} is not higher than the reduction potential of the dication in the general formula 1 by 3.1 V or more, the device may be slightly colored in the decolorized state and the transmittance may decrease. When the electrochromic compound is attached to the conductive or semiconductor nanostructures, the anion and the dication (the dication in the general formula 1) form a CT (Charge Transfer) complex by CT transition. It may absorb light of a certain wavelength. At this time, the absorption wavelength due to CT transition is larger than 400 nm, that is, the energy level difference between the anion LUMO (Lowest Unoccupied Molecular Orbital) and the dication HOMO (Highest Occupied Molecular Orbital) is 3.1 eV. If it is less than 3.1 V, that is, if the potential difference between the oxidation potential of the anion and the reduction potential of the dication is less than 3.1 V, the electrochromic element appears to be colored visually, which is not preferable. In such a case, the device often looks yellow due to a decrease in transmittance, especially in the short wavelength region.

Examples of ^{X −} in which the potential difference between the oxidation potential of the anion and the reduction potential of the dication is 3.1 V or more include _{(FSO 2} ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (CN) ₄ B ⁻ , and so on. _{^{BF 4 -, CF 3 BF 3}} -, PF 6 -, ClO 4 -, (C 2 F 5 SO 2) 2 N -, (C 4 F 9 SO 2) 2 N -, CF 3 SO 3, C 2 F Examples thereof include _{5 SO 3} , C ₄ F ₉ SO ₃ , (C ₂ F ₅ ) ₃ PF ₃ ⁻ , and (CF ₃ SO ₂ ) ₃ C ^−. One of these may be used alone, or a plurality of types may be used in combination.

As a more preferred embodiment, X ⁻ is one selected from (FSO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (CN) ₄ B ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , and ClO ₄ ^−. Or there are multiple types. Since these anions are so large that it is difficult to form a CT complex with a dication, they are stable, and they are not too large to obtain a sufficient response rate, the use of these anions not only provides excellent transparency but also responds. An element having excellent properties can be obtained.

As a more preferred embodiment, X ⁻ is one or more selected from (FSO ₂ ) ₂ N ⁻ and (CF ₃ SO ₂ ) ₂ N ^−. Since these anions are particularly excellent in stability and responsiveness, it is possible to obtain an element having further excellent durability by using these anions.

In the most preferable embodiment, X ⁻ is (CF ₃ SO ₂ ) ₂ N ⁻ (hereinafter, ^{may be referred to as “TFSI −} ”). By using (CF ₃ SO ₂ ) ₂ N ⁻ , a deeper color is developed. A device capable of achieving a concentration can be obtained. The mechanism has not been clarified, but the distance between dication molecules, the packing structure, and the conductivity during the adhesion process when the electrochromic compound adheres to the nanostructure. Alternatively, it is considered that the adhesion state such as the surface state of the semiconductor nanostructure has an influence. The conductivity or the surface state of the semiconductor nanostructure at the time of the adhesion process is the nanostructure of the electrochromic compound solution. It is presumed that it changes depending on the wettability of the solution when applied to the body and the influence of pH.

In a preferred form of the electrochromic compound, W ²⁺ in the general formula 1 is represented by the following structural formula 1. By doing so, the stability of the color development state of the dication is enhanced, and a more reliable device can be obtained.
[Structural formula 1]

In another preferred form of the electrochromic compound, k in the general formula 1 is 0. By doing so, the solubility of the compound is increased, and more electrochromic compounds can be easily attached to the conductive or semiconductor nanostructures, which leads to an improvement in the color development density.

In still another preferred form of the electrochromic compound, R ₃ in the general formula 1 is represented by the following general formula 3 and R ₄ is represented by the following general formula 4. By doing so, the durability of the electrochromic compound is increased, and a more reliable element can be obtained.
[General formula 3]
[General formula 4]
However, in the general formula 3, m represents an integer of 0 or 1 to 10, n represents an integer of 0 or 1 to 10 in the general formula 4, and m and n may have the same value but are different from each other. You may.

Specific examples of the electrochromic compound of the present invention include those shown below, but the electrochromic compound is not limited thereto.

<Example compound 1-1>

<Example compound 1-2>

<Example compound 1-3>

<Example compound 1-4>

<Example compound 1-5>

<Example compound 1-6>

<Example compound 1-7>

<Example compound 1-8>

<Example compound 1-9>

<Example compound 1-10>

<Example compound 1-11>

<Example compound 1-12>

<Example compound 1-13>

<Example compound 1-14>

<Example compound 1-15>

<Example compound 1-16>

<Example compound 1-17>

<Example compound 1-18>

<Example compound 1-19>

<Example compound 1-20>

<Example compound 1-21>

<Example compound 1-22>

<Example compound 1-23>

<Example compound 1-24>

<Example compound 1-25>

<Example compound 1-26>

<Example compound 1-27>

<Example compound 1-28>

<Example compound 1-29>

<Example compound 1-30>

<Example compound 1-31>

<Example compound 1-32>

<Example compound 1-33>

<Example compound 1-34>

As a method for confirming the ion species of the electrochromic layer, various known methods can be used, and ion chromatography is particularly effective.

As an example of the confirmation method, the electrochromic element is decomposed to expose the electrochromic layer, and the electrochromic layer is washed with a solvent such as water or alcohol, or the electrochromic layer is immersed in the solvent to electrochromic in the solvent. Dissolve the compound. At this time, if necessary, heating or hydrolysis treatment by addition of acid or alkali may be used in combination. Further, in order to prevent the mixing of ions in the electrolyte layer, the electrochromic compound may be dissolved by the above method after cleaning the electrochromic layer in advance. By analyzing the solution thus obtained by using ion chromatography, the ionic species can be identified.

However, care must be taken because trace impurities such as ^{OH −} and halide ions may be mixed in from the atmosphere or other members during the analysis operation.

The ^{method for measuring the oxidation potential of X −} can be measured by using a known method. For example, in the case of electrochemical measurement, the measurement method should be the same as that for measuring the reduction potential of the electrochromic compound. Is preferable. Specifically, it is preferable to prepare the working electrode, counter electrode, reference electrode, solvent, electrolyte, measurement conditions, and the like to be used. When the oxidation-reduction potential is measured by cyclic voltammetry, the electrode potential is first swept in the reduction direction to measure the reduction potential of the electrochromic compound of the present invention, and then the electrode potential is swept in the oxidation direction as it is to obtain X ⁻ . It is easy to measure the oxidation potential because the reaction potentials can be compared in exactly the same system. ^{On the other hand, if the oxidation potential of X −} cannot be measured simultaneously in the same system due to the solubility in the solvent or the potential window of the measurement system, a salt using a salt having a high potential window on the oxidation side as the counter cation of ^{X − is used.} By preparing and measuring the oxidation potential of the salt, the oxidation potential of X ⁻ can be measured. However, since there are not many measurement systems with a wide potential window up to a potential 3.1 V or more higher than the reduction potential of the electrochromic compound of the present invention, it is compared with the background current value of the same measurement system that does not contain the salt of ^{X −.} It is good to estimate the oxidation potential while doing so.

<Second electrochromic layer>
The electrochromic device of the present invention preferably further has a second electrochromic layer on the second electrode. The second electrochromic layer contains a second electrochromic compound.
It should be noted that the inclusion of the second electrochromic compound in the second electrochromic layer is in addition to the embodiment in which the second electrochromic compound is present in the second electrochromic layer while retaining its structure. Also included is an embodiment in which the second electrochromic compound is present as a constituent component of the polymer.
In other words, when the second electrochromic layer contains the second electrochromic compound, it means that the second electrochromic layer contains the second electrochromic compound as a constituent component.

By having the second electrochromic layer, the two electrochromic layers develop and decolorize, so that a deeper color density can be obtained.

The second electrochromic layer is laminated on the second electrode, and only one layer may be laminated, or two or more layers may be laminated.

<< Second electrochromic compound >>
As the second electrochromic compound, a known electrochromic compound can be used without particular limitation.

Specifically, as electrochromic compounds, azobenzene-based, anthraquinone-based, diarylethene-based, dihydroprene-based, styryl-based, styrylspiropirane-based, spiroxazine-based, spirothiopyran-based, thioindigo-based, tetrathiafluvalene-based, terephthalic acid-based, triphenyl Low molecules such as methane, triphenylamine, naphthopyrane, viologen, pyrazoline, phenazine, phenylenediamine, phenoxazine, phenothiazine, phthalocyanine, fluorane, flugide, benzopyran, metallocene, etc. Organic electrochromic materials and conductive polymer compounds such as polyaniline and polythiophene are used. These may be used individually by 1 type, or may be used in combination of a plurality of types.

More preferably, the second electrochromic layer contains a polymer obtained by polymerizing a polymerizable material containing a radically polymerizable compound having a triarylamine skeleton. This makes it possible to obtain an electrochromic element having excellent durability.
It is preferable that the second electrochromic layer is essentially composed of only a polymer. Here, "consisting essentially of a polymer" means that the second electrochromic layer is allowed to contain components other than the polymer as long as the above effects are not impaired.

More preferably, the second electrochromic layer contains a polymer obtained by polymerizing a polymerizable material containing a radically polymerizable compound having a triarylamine skeleton and a radically polymerizable compound having a tetraarylbenzidine skeleton. This makes it possible to obtain an electrochromic element having more durability.

The radically polymerizable compound having the triarylamine skeleton and the radically polymerizable compound having the tetraarylbenzidine skeleton are important for imparting an electrochromic function having a redox reaction on the surface of the second electrode. Examples of the radically polymerizable compound having a triarylamine skeleton include compounds represented by the following general formula 5.
[General formula 5]
An-Bm
However, when n = 2, m is 0, and when n = 1, m is 0 or 1. At least one of A and B has a radically polymerizable functional group. The A has a structure represented by the following general formula 6, and is coupled to the B at any position from R _{1 to R 15.} The B has a structure represented by the following general formula 7, and is coupled to the A at any position from R _{16 to R 21.}
The radically polymerizable compound having a tetraarylbenzidine skeleton is one of the compounds represented by the general formula 5 with n = 2.
[General formula 6]
[General formula 7]
However, in the general formulas 6 and 7, R ₁ to R ₂₁ are all monovalent groups and may be the same or different from each other, and at least one of the monovalent groups is a radical. It is a polymerizable functional group.

-Univalent base-
As the monovalent group in the general formula 6 and the general formula 7, for example, even if each independently has a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxyl group, and a substituent. A good alkoxycarbonyl group, 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 substituent. It may have a monoalkylaminocarbonyl group which may have a substituent, a dialkylaminocarbonyl group which may have a substituent, a monoarylaminocarbonyl group which may have a substituent, or a substituent. A good diarylaminocarbonyl group, a sulfonic acid group, an alkoxysulfonyl group which may have a substituent, an aryloxysulfonyl group which may have a substituent, an alkylsulfonyl group which may have a substituent, It has an arylsulfonyl group that may have a substituent, a sulfonamide group, a monoalkylaminosulfonyl group that may have a substituent, a dialkylaminosulfonyl group that may have a substituent, and a substituent. Monoarylaminosulfonyl group which may have a substituent, diarylaminosulfonyl group which may have a substituent, an amino group, a monoalkylamino group which may have a substituent, and a substituent which may have a substituent. It may have a good dialkylamino group, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, and a substituent. An aryl group, an alkoxy group which may have a substituent, an aralkyl group which may have a substituent, an aryloxy group which may have a substituent, and an alkylthio which may have a substituent. Examples thereof include a group, an arylthio group which may have a substituent, 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 halogen atom, an alkenyl group and an alkynyl group are particularly preferable from the viewpoint of stable operation.

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, a butyl group and the like. 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, a naphthylmethyl group and the like. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group and the like. Examples of the aryloxy group include a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 4-methoxyphenoxy group, a 4-methylphenoxy group and the like. 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 such as a phenoxy group. Examples thereof include an aryl group such as a group, a phenyl group and a naphthyl group, and an aralkyl group such as a benzyl group and a phenethyl group.

-Radical polymerizable functional group-
The radically polymerizable functional group may be any group as long as it has a carbon-carbon double bond and is radically polymerizable. Examples of the radically polymerizable functional group include the 1-substituted ethylene functional group and the 1,1-substituted ethylene functional group shown below.

(1) Examples of the 1-substituted ethylene functional group include a functional group represented by the following general formula (i).
However, in the general formula (i), X ₁ is an arylene group which may have a substituent, an alkenylene group which may have a substituent, an −CO− group, an −COO− group, or −CON (R). ₁₀₀ ) -Group [R ₁₀₀ represents a hydrogen atom, an alkyl group, an aralkyl group, and an aryl group. ], Or -S- group.
Examples of the arylene group of the general formula (i) include a phenylene group and a naphthylene group which may have a substituent. Examples of the alkenylene group include an ethenylene group, a propenylene group, a butenylene group and the like. Examples of the alkyl group include a methyl group and an ethyl group. Examples of the aralkyl group include a benzyl group, a naphthylmethyl group, a phenethyl group and the like. Examples of the aryl group include a phenyl group and a naphthyl group.
Specific examples of the radically polymerizable functional group represented by the general formula (i) include a vinyl group, a styryl group, a 2-methyl-1,3-butadienyl group, a vinylcarbonyl group, an acryloyl group, an acryloyloxy group, and an acryloyl group. Examples thereof include an amide group and a vinylthioether group.

(2) Examples of the 1,1-substituted ethylene functional group include a functional group represented by the following general formula (ii).
However, in the general formula (ii), Y is an alkyl group which may have a substituent, an aralkyl group which may have a substituent, an aryl group which may have a substituent, a halogen atom, or a cyano. Group, nitro group, alkoxy group, -COOR ₁₀₁ group [R ₁₀₁ may have a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, and a substituent. The aryl group, or CONR ₁₀₂ R ₁₀₃ (R ₁₀₂ and R ₁₀₃ may have a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. Represents an aryl group and may be the same or different from each other.)]. Further, X ₂ represents the same substituent, single bond, and alkylene group as _{X 1} of the general formula (i). However, at least one of Y and X ₂ is an oxycarbonyl group, a cyano group, an alkenylene group, or an aromatic ring.
Examples of the aryl group of the general formula (ii) include a phenyl group and a naphthyl group. Examples of the alkyl group include a methyl group and an ethyl group. Examples of the alkoxy group include a methoxy group and an ethoxy group. Examples of the aralkyl group include a benzyl group, a naphthylmethyl group, a phenethyl group and the like.

Specific examples of the radically polymerizable functional group represented by the general formula (ii) include α-acryloyloxy chloride group, methacryloyl group, methacryloyloxy group, α-cyanoethylene group, α-cyanoacryloyloxy group and α-. Examples thereof include a cyanophenylene group and a methacryloylamino group.

Examples _{of the substituent further substituted with the substituents for X 1} , X ₂ and Y include an alkyl group such as a halogen atom, a nitro group, a cyano group, a methyl group and an ethyl group, a methoxy group and an ethoxy group. Examples thereof include an alkoxy group such as, an aryloxy group such as a phenoxy group, an aryl group such as a phenyl group and a naphthyl group, and an aralkyl group such as a benzyl group and a phenethyl group.

Among the radically polymerizable functional groups, an acryloyloxy group and a methacryloyloxy group are particularly preferable.

As the radically polymerizable compound having the triarylamine skeleton, compounds represented by the following general formulas (2-1) to (2-3) are preferably mentioned.
[General formula (2-1)]
[General formula (2-2)]
[General formula (2-3)]
In the general formulas (2-1) to (2-3), R ₂₇ to R ₈₉ are all monovalent radicals, which may be the same or different from each other, and are the monovalent radicals. At least one of them is a radically polymerizable functional group. Examples of the monovalent group and the radically polymerizable functional group include the same ones as those in the general formula 5.
Of these, the compound represented by the general formula (2-1) is a radically polymerizable compound having the tetraarylbenzidine skeleton.
Examples of the exemplary compounds represented by the general formula 5 and the general formulas (2-1) to (2-3) include those shown below. The radically polymerizable compound having the triarylamine skeleton and the radically polymerizable compound having the tetraarylbenzidine skeleton are not limited thereto.

<Example compound 3-1>
<Example compound 3-2>
<Example compound 3-3>
<Example compound 3-4>
<Example compound 3-5>
<Example compound 3-6>
<Example compound 3-7>
<Example compound 3-8>
<Example compound 3-9>
<Example compound 3-10>
"Me" represents a methyl group.
<Example compound 3-11>
<Example compound 3-12>
<Example compound 3-13>
<Example compound 3-14>
<Example compound 3-15>
<Example compound 3-16>
<Example compound 3-17>
<Example compound 3-18>
<Example compound 3-19>
<Example compound 3-20>
<Example compound 3-21>
<Example compound 3-22>
<Example compound 3-23>
<Example compound 3-24>
<Example compound 3-25>
<Example compound 3-26>
<Example compound 3-27>
<Example compound 3-28>
<Example compound 3-29>
<Example compound 3-30>
<Example compound 3-31>
<Example compound 3-32>
<Example compound 3-33>
<Example compound 3-34>
<Example compound 3-35>
<Example compound 3-36>
<Example compound 3-37>
<Example compound 3-38>
<Example compound 3-39>
<Example compound 3-40>

<< Other polymerizable compounds >>
The polymerizable material for forming the second electrochromic layer may contain other polymerizable compounds, if necessary.

The other radically polymerizable compound is different from the radically polymerizable compound having the triarylamine skeleton. In addition, the other radically polymerizable compound is a compound having at least one radically polymerizable functional group. Examples of the other radical-polymerizable compounds include monofunctional radical-polymerizable compounds, bifunctional radical-polymerizable compounds, trifunctional or higher-functional radical-polymerizable compounds, functional monomers, and radical-polymerizable oligomers. Among these, a radically polymerizable compound having two or more functions is particularly preferable. The radically polymerizable functional group in the other radically polymerizable compound is the same as the radically polymerizable functional group in the radically polymerizable compound having a triarylamine skeleton, and among these, the acryloyloxy group and the methacryloyloxy group are used. Especially preferable.

Examples of the monofunctional radically polymerizable compound include 2- (2-ethoxyethoxy) ethyl acrylate, methoxypolyethylene glycol monoacrylate, methoxypolyethylene glycol monomethacrylate, phenoxypolyethylene glycol acrylate, 2-acryloyloxyethyl succinate, and 2 -Ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-ethylhexyl carbitol acrylate, 3-methoxybutyl acrylate, benzyl acrylate, cyclohexyl acrylate, isoamyl acrylate, isobutyl acrylate, methoxytriethylene glycol Examples thereof include acrylate, phenoxytetraethylene glycol acrylate, cetyl acrylate, isostearyl acrylate, stearyl acrylate, and styrene monomer. These may be used alone or in combination of two or more.

Examples of the bifunctional radically polymerizable compound include 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, and 1,6-hexanediol diacrylate, 1. , 6-Hexanediol dimethacrylate, diethylene glycol diacrylate, polyethylene glycol diacrylate, neopentyl glycol diacrylate, EO-modified bisphenol A diacrylate, EO-modified bisphenol F diacrylate, neopentyl glycol diacrylate and the like. These may be used alone or in combination of two or more.

Examples of the trifunctional or higher functional radical polymerizable compound include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, EO-modified trimethylolpropane triacrylate, PO-modified trimethylolpropane triacrylate, and caprolactone-modified trimethylolpropane. Triacrylate, HPA-modified trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate, ECH-modified glycerol triacrylate, EO-modified glycerol triacrylate, PO-modified glycerol triacrylate, tris (acryloxy) Ethyl) isocyanurate, dipentaerythritol hexaacrylate (DPHA), caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkyl-modified dipentaerythritol pentaacrylate, alkyl-modified dipentaerythritol tetraacrylate, alkyl-modified dipentaerythritol Examples thereof include trimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO-modified phosphate triacrylate, and 2,2,5,5-tetrahydroxymethylcyclopentanone tetraacrylate. These may be used alone or in combination of two or more. In the above, EO modification refers to ethylene oxy modification, and PO modification refers to propylene oxy modification.

Examples of the functional monomer include those substituted with fluorine atoms such as octafluoropentyl acrylate, 2-perfluorooctyl ethyl acrylate, 2-perfluorooctyl ethyl methacrylate, and 2-perfluoroisononyl ethyl acrylate. Acryloyl polydimethylsiloxane ethyl, methacryloyl polydimethyl siloxane ethyl, acryloyl polydimethyl siloxane propyl, acryloyl polydimethyl siloxane butyl, diacryloyl poly having a siloxane repeating unit of 20 to 70 described in JP-A-60503 and JP-A-6-45770. Examples thereof include vinyl monomers having a polysiloxane group such as dimethylsiloxane diethyl, acrylates and methacrylates. These may be used alone or in combination of two or more.

Examples of the radically polymerizable oligomer include epoxy acrylate-based oligomers, urethane acrylate-based oligomers, polyester acrylate-based oligomers, and the like.

At least one of the radical-polymerizable compound having the triarylamine skeleton and another radical-polymerizable compound different from the radical-polymerizable compound having the triarylamine skeleton has two or more radical-polymerizable functional groups. It is preferable from the viewpoint of forming a crosslinked product.

The content of the radically polymerizable compound having a triarylamine skeleton is preferably 10% by mass or more and 100% by mass or less, and 30% by mass or more and 90% by mass, based on the total amount of the material exhibiting the electrochromic function in the polymerizable material. % Or less is more preferable. When the content is 10% by mass or more, the electrochromic function of the second electrochromic layer can be sufficiently exhibited, the durability is good with repeated use by a applied voltage, and the color development sensitivity is good. Even if the content is 100% by mass, the electrochromic function is possible, and in this case, the color development sensitivity with respect to the thickness is the highest. On the contrary, the compatibility with the ions required for the transfer of electric charge may be lowered, so that the electrical characteristics deteriorate due to the deterioration of durability due to repeated use by the applied voltage. Although it cannot be said unconditionally because the required electrical characteristics differ depending on the process used, 30% by mass or more and 90% by mass or less is particularly preferable in consideration of the balance between the characteristics of color development sensitivity and repeatability.

<< Polymerization Initiator >>
The polymerizable material may contain a polymerization initiator (for example, a radical polymerization initiator), if necessary, in order to efficiently proceed with the polymerization reaction of the radically polymerizable compound having the triarylamine skeleton.
Examples of the polymerization initiator include a thermal polymerization initiator and a photopolymerization initiator, but a photopolymerization initiator is preferable from the viewpoint of polymerization efficiency.

The thermal polymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 2,5-dimethylhexane-2,5-dihydroperoxide, dicumyl peroxide, benzoyl peroxide, etc. t-Butyl cumyl peroxide, 2,5-dimethyl-2,5-di (peroxybenzoyl) hexin-3, di-t-butylbeloxide, t-butylhydrobeloxide, cumenehydrobeloxide, lauroyl peroxide Peroxide-based initiators such as; azobisisobutyrynitrile, azobiscyclohexanecarbonitrile, methyl azobisisobutyrate, azobisisobutyramidine hydrochloride, azo-based initiators such as 4,4'-azobis-4-cyanovaleric acid, etc. And so on. These may be used alone or in combination of two or more.

The photopolymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. For example, diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy -Cyclohexyl-phenyl-ketone, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1, 2-Hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-2-morpholino (4-methylthiophenyl) propan-1-one, 1-phenyl-1,2-propanedione-2- ( O-ethoxycarbonyl) acetophenone-based or ketal-based photopolymerization initiators such as oxime; benzophenone-based photopolymerization initiators such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether, benzoin isopropyl ether; benzophenone, 4-hydroxy Benzophenone-based photopolymerization initiators such as benzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether, acrylicized benzophenone, 1,4-benzoylbenzene; 2-isopropylthioxanthone, 2 -Thioxanthone-based photopolymerization initiators such as chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2,4-dichlorothioxanthone; and the like.

Examples of other photopolymerization initiators include ethylanthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, and bis (2,4,6-trimethylbenzoyl). Phenylphosphine oxide, bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, methylphenylglioxyester, 9,10-phenanthrene, aclysine compounds, triazine compounds, imidazole compounds, etc. Can be mentioned. These may be used alone or in combination of two or more.

It should be noted that those having a photopolymerization promoting effect can be used alone or in combination with the photopolymerization initiator. For example, triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, ethyl benzoate (2-dimethylamino), 4,4'-dimethylaminobenzophenone, and the like can be mentioned.

The content of the polymerization initiator in the polymerizable material when forming the second electrochromic layer is 0.5 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the total amount of the radically polymerizable compound. Preferably, it is preferably 1 part by mass or more and 20 parts by mass or less.
Here, the radically polymerizable compound refers to the total amount of the radically polymerizable compound contained in the polymerizable material.

<Electrolyte layer>
The electrolyte layer contains at least an electrolyte.

<< Electrolyte >>
The electrolyte is not particularly limited and known ones can be used, but the anion of the electrolyte is a monovalent anion having an oxidation potential that is 3.1 V or more higher than the reduction potential of the dication in the general formula 1. It is preferable to have. Such anions include, for example, (FSO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (CN) ₄ B ⁻ , BF ₄ ⁻ , CF ₃ BF ₃ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , _{(C 2 F 5 SO 2)} 2 N -, (C 4 F 9 SO 2) 2 N -, CF 3 SO 3, C 2 F 5 SO 3, C 4 F 9 SO 3, (C 2 F 5) 3 PF ₃ ⁻ , (CF ₃ SO ₂ ) ₃ C ^{− and the} like can be mentioned. By using an electrolyte having these anions, it is possible to prevent coloring due to CT transition of the electrochromic compound even when the anion of the electrochromic compound and the anion of the electrolyte are ion-exchanged in the device, so that the electrochromic is more transparent. The element can be obtained.

More preferably, the anions of the electrolyte are (FSO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (CN) ₄ B ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , and ClO ₄ ⁻ . These anions can prevent coloring due to CT transition of the electrochromic compound even when the anion of the electrochromic compound and the anion of the electrolyte are ion-exchanged in the device, are more stable, and are large enough to obtain a sufficient response rate. Therefore, by using these anions, it is possible to obtain an element having not only excellent transparency but also excellent responsiveness.

The cation of the electrolyte is not particularly limited, and the electrolyte includes metal ion systems such as Li salt, Na salt, K salt, and Mg salt, and N, N-dimethylimidazole salt, N, N-methylethyl imidazole salt. , N, N-Methylpropylimidazole salt, N, N-methylbutylimidazole salt, N, N-allylbutylimidazole salt, and other imidazole derivatives; N, N-dimethylpyridinium salt, N, N-methylpropylpyridinium salt, etc. Pyridinium derivatives of: N, N-dimethylpyrrolidinium salt, N-ethyl-N-methylpyrrolidinium salt, N-methyl-N-propylpyrrolidinium salt, N-butyl-N-methylpyrrolidinium salt, Pyrrolidinium derivatives such as N-methyl-N-pentylpyrrolidinium salt and N-hexyl-N-methylpyrrolidinium salt; aliphatic quaternary ammonium salts such as trimethylpropylammonium salt, trimethylhexylammonium salt and triethylhexylammonium salt. And so on.

The anions and cations can be used in any combination, and one type may be used alone or a plurality of types may be used in combination.

In particular, a combination of anion and cation having a melting point of the electrolyte of room temperature or lower is preferable. That is, it is preferable to use an ionic liquid as the electrolyte. Further, an organic ionic liquid is preferably used because it has a molecular structure showing the liquid in a wide temperature range including room temperature.

The electrolyte may be dissolved directly in any of the photopolymerizable monomers, oligomers, and liquid crystal materials. If the solubility is poor, the solution may be dissolved in a small amount of solvent and the solution may be mixed with any of a photopolymerizable monomer, an oligomer, and a liquid crystal material.

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 and the like.

The electrolyte layer does not have to be a low-viscosity liquid, and can take various forms such as a gel form, a polymer crosslinked type, and a liquid crystal dispersed type. By forming the electrolyte in the form of a gel or a solid, advantages such as improvement in device strength and improvement in reliability can be obtained.

As a solidification method, it is preferable to hold the electrolyte in the polymer resin. This is because high ionic conductivity and solid strength can be obtained.

Further, as the polymer resin, a photocurable resin is preferable. This is because the device can be manufactured at a low temperature and in a short time as compared with the method of forming a thin film by thermal polymerization or evaporation of a solvent.
The average thickness of the electrolyte layer made of the electrolyte is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 100 nm or more and 100 μm or less.
The average thickness of the electrolyte layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.1 times or more and 1000 times or less the average thickness of the first electrochromic layer.

<1st electrode and 2nd electrode>
The material of the first electrode and the second electrode is not particularly limited, and a commonly used conductor can be used.
The transparent electrode is not particularly limited as long as it is a conductive transparent material, and can be appropriately selected depending on the intended purpose. For example, tin-doped indium oxide (hereinafter referred to as “ITO”) and fluorine-doped Examples thereof include tin oxide, antimony-doped tin oxide, and inorganic materials such as zinc oxide. Among _{these, InSnO, GaZnO, SnO, In} 2 O 3, ZnO is preferable.
Furthermore, transparent carbon nanotubes and other highly conductive non-transparent materials such as Au, Ag, Pt, and Cu are formed in a fine network to improve conductivity while maintaining transparency. Electrodes may be used.
The thickness of each of the first electrode and the second electrode is adjusted so that the electric resistance value required for the redox reaction of the electrochromic layer can be obtained.
When ITO is used as the material for the first electrode and the second electrode, the thickness of each of the first electrode and the second electrode is preferably, for example, 50 nm or more and 500 nm or less.

As a method for producing each of the first electrode and the second electrode, a vacuum vapor deposition method, a sputtering method, an ion plating method, or the like can be used.
There is no particular limitation as long as the materials of the first electrode and the second electrode can be applied and formed, and for example, a spin coating method, a casting method, a microgravure coating method, a gravure coating method, a bar coating method, and a roll. Coating method, Wirer coating method, Dip coating method, Slit coating method, Capillary coating method, Spray coating method, Nozzle coating method, Gravure printing method, Screen printing method, Flexographic printing method, Offset printing method, Reverse printing method, Inkjet printing Various printing methods such as a method can be used.

<Other parts>
The electrochromic device of the present invention may further include other members, if necessary.
The other members are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a support, a sealing material, and a protective layer.

<< Support >>
As the support, a well-known organic material or inorganic material can be used as it is as long as it is a transparent material that can support each layer.
As the support, for example, a glass substrate such as non-alkali glass, borosilicate glass, float glass, and soda-lime glass can be used. Further, as the support, a resin substrate such as a polycarbonate resin, an acrylic resin, a polyethylene, a polyvinyl chloride, a polyester, an epoxy resin, a melamine resin, a phenol resin, a polyurethane resin, or a polyimide resin may be used.
Further, the surface of the support may be coated with a transparent insulating layer, a UV cut layer, an antireflection layer or the like in order to enhance water vapor barrier property, gas barrier property, ultraviolet ray resistance, and visibility.
The shape of the support may be rectangular or round, and is not particularly limited.
The support may be a plurality of superpositions. For example, the water vapor barrier property and the gas barrier property can be enhanced by forming a structure in which the electrochromic element is sandwiched between two glass substrates.

<< Sealing material >>
The encapsulant has functions such as sealing the side surface of the bonded electrochromic element to prevent leakage of electrolytes, and preventing the intrusion of unnecessary substances such as moisture and oxygen in the atmosphere for stable operation of the electrochromic element. Have. The sealing material is not particularly limited, and for example, an ultraviolet curable type resin or a thermosetting type resin can be used, and specific examples thereof include acrylic type, urethane type, and epoxy type resins.

<< Protective layer >>
The role of the protective layer is unnecessary for protecting the element from external stress and chemicals in the cleaning process, preventing leakage of electrolytes, and for stable operation of electrochromic elements such as moisture and oxygen in the atmosphere. For example, to prevent intrusion.
The thickness of the protective layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 μm or more and 200 μm or less.
As the material of the protective layer, for example, an ultraviolet curable type resin or a thermosetting type resin can be used, and specific examples thereof include acrylic type, urethane type, and epoxy type resins.

<Use>
Since the electrochromic element of the present invention has excellent transparency, for example, an electrochromic device, an electrochromic display, a large display board such as a stock price display board, an antiglare mirror, a dimming glass, a dimming lens, and a dimming. It can be suitably used for a dimming element such as a film, a low voltage drive element such as a touch panel type key switch, an optical switch, an optical memory, an electronic paper, an electronic album, and the like.

Hereinafter, examples of the present invention will be described, but the present invention is not limited to the following examples.

<Measurement of dication reduction potential>
Octylbiologene dibromide (Tokyo Kasei) was dissolved in propylene carbonate to a concentration of 0.01 mol / L, and 1-ethyl-3-methyl-imidazolium bis (fluorosulfonyl) imide (EMIMFSI, Kanto Chemical Co., Inc.) was added as an electrolyte. The measurement solution was prepared by dissolving the mixture so as to be 0.1 mol / L. A glassy carbon electrode was used as the working electrode, a platinum electrode was used as the counter electrode, and an Ag / Ag + electrode partitioned by ion-transmitting glass was used as the reference electrode. Cyclic voltammetry was performed using a potentiostat to measure the reduction potential of the dication of octylviologen. The dications of Exemplified Compounds 1-1 to 1-18 and 1-24 to 1-26 having a common viologen skeleton show the same reduction potential.
Further, the exemplified compounds 1-19 to 1-23 were dissolved in propylene carbonate so as to be 0.01 mol / L, and the reduction potentials of the dications were measured by the same method. As a result, the reduction potentials of the dications were all octylbiologens. It was lower than the reduction potential of the dication.

<Measurement of anion oxidation potential>
Subsequently, 1-ethyl-3-methyl-imidazolium bis (fluorosulfonyl) imide was dissolved in propylene carbonate so as to be 0.1 mol / L as an anion of Exemplified Compound 1-1 and Exemplified Compound 1-7, and the oxidation side was obtained. The potential was swept to measure the oxidation potential of the FSI anion. As a result, no conspicuous reaction current was observed even at a potential 3.1 V higher than the reduction potential of the dication of octylviologen. From this, it can be seen that the oxidation potential of the bis (fluorosulfonyl) imide anion is 3.1 V or more higher than the reduction potential of the dications of Exemplified Compounds 1-1 to 1-26.

Similarly, 1-ethyl-3-methyl-imidazolium bis (trifluoromethanesulfonyl) imide as an anion of Exemplified Compounds 1-2 and 1-8 to 1-34, and 1-ethyl as an anion of Exemplified Compound 1-3. -3-Methyl-imidazolium tetracyanoborate, 1-ethyl-3-methyl-imidazolium tetrafluoroborate as an anion of Exemplified Compound 1-4, 1-butyl-3-methyl as an anion of Exemplified Compound 1-5 -Imidazolium hexafluorophosphate was dissolved in propylene carbonate so that tetrabutylammonium perchloride was 0.1 mol / L as an anion of Exemplified Compound 1-6, and the potential was swept to the oxidation side to sweep each anion. The oxidation potential was measured.
As a result, no conspicuous reaction current was observed even at a potential 3.1 V higher than the reduction potential of the dication of octylviologen. In all measurements, the oxidation current starts to flow from the vicinity where the potential exceeds 3.1 V higher than the reduction potential of the dication of octylviologen, and it is unlikely that all anions have the same oxidation potential, so this current is carbonated. It is considered to be the current due to the oxidation of propylene. Therefore, the specific oxidation potential of each anion is unknown, but there is no doubt that it is 3.1 V or more higher than the reduction potential of the dication of octylviologen. From this, it can be seen that the oxidation potentials of these anions are 3.1 V or more higher than the reduction potentials of the dications of Exemplified Compounds 1-1 to 1-26.

(Example 1)
<Preparation of electrochromic layer>
Titanium oxide nanoparticle dispersion (trade name: SP210, manufactured by Showa Titanium Co., Ltd., average particle size:) on an ITO glass substrate (40 mm × 40 mm, thickness 0.7 mm, ITO film thickness: about 100 nm) as the first electrode. Approximately 20 nm) was applied by a spin coating method and annealed at 120 ° C. for 15 minutes to form a nanostructured semiconductor material composed of a titanium oxide particle film having a thickness of 2.5 μm.
A 40 mmol% 2,2,3,3-tetrafluoropropanol solution of Exemplified Compound 1-1 was applied to the titanium oxide particle film as a coating solution by a spin coating method, and annealed at 120 ° C. for 10 minutes. A first electrochromic layer having a thickness of 2.5 μm was formed on the electrode of the above, with the example compound 1-1 adhered to the surface of the titanium oxide particles.

<Preparation of the second electrochromic layer>
The above-mentioned exemplified compounds 3-10 and tetra having a triarylamine skeleton as a second electrochromic compound on an ITO glass substrate (40 mm × 40 mm, thickness 0.7 mm, ITO film thickness: about 100 nm) as a second electrode. The above-mentioned exemplified compound 3-40 having an arylbenzidine skeleton, Blemmer AME400 (Nichiyu) and Brenmer ADE400A (Nichiyu) as other polymerizable compounds, irgacure184 as a polymerization initiator, and 2-butanone as a solvent by mass ratio. The solution mixed with (Exemplary Compound 3-10: Exemplified Compound 3-40: AME400: ADE400A: irgacure184: 2-Butanone = 3: 7: 6: 4: 0.1: 80) was applied by spin coating and dried. A second electrochromic layer having a thickness of 1.3 μm was formed on the second electrode by UV curing in a nitrogen atmosphere.

<filling of electrolyte>
First, 195 parts by mass of Blemmer AME400 (Nichiyu) and 195 parts by mass of Brenmer ADE400A (Nichiyu) as a monomer, 10 parts by mass of IRGACURE184 (BASF) as a polymerization initiator, and 1-ethyl-3-methyl-imidazolium bis as an electrolyte. 60 parts by mass of (fluorosulfonyl) imide (EMIMFSI, Kanto Chemical Co., Inc.) was mixed to prepare a monomer composition solution, and an electrolyte solution was obtained.
50 μL of the obtained electrolyte solution was measured with a micropipette and added dropwise to the ITO glass substrate having the first electrochromic layer. An ITO glass substrate having a second electrochromic layer was bonded onto the electrode so that a lead-out portion of the electrode was provided, to produce a bonded element.
The obtained bonding element was irradiated with a UV (wavelength 250 nm) irradiation device (SPOT CURE manufactured by Ushio, Inc.) at 10 mW for 60 seconds. From the above, an electrochromic device was manufactured.
The average thickness of the electrolyte layer was 30 μm.

<Evaluation of colorless transparency>
The transmittance of the manufactured electrochromic device was measured by USB4000 manufactured by Ocean Optics, and the yellow index (YI) value was calculated from the obtained spectrum. The calculation results are shown in Table 1-1.

<Evaluation of color density>
With respect to the produced electrochromic device, ^{the transmittance at 610 nm when a charge of 10 mC / cm 2} was applied per unit area of the color development area was measured by USB 4000 manufactured by Ocean Optics. The measurement results are shown in Table 1-1.

<Durability evaluation>
Regarding the manufactured electrochromic element, the ambient temperature was 28 ° C. and the light intensity was 250 W / m ² in the ^{weather resistance tester SUNTEST CPS + (Toyo Seiki) in a state where a charge of 5 mC / cm 2} was applied per unit area of the color development area to develop the color. A durability test was conducted for 50 hours. After the test, the element was decolorized, the transmittance was measured with USB4000 manufactured by Ocean Optics, and the yellow index (YI) value was calculated from the obtained spectrum. The yellow index value was calculated by the same method as the above-mentioned evaluation of colorless transparency. ΔYI was calculated as to how much this YI increased from the value before the durability test. The calculation results are shown in Table 1-1.

(Examples 2 to 90)
Regarding the method for producing an electrochromic device, an electrochromic device was produced and evaluated in the same manner as in Example 1 except that each electrochromic compound and electrolyte was changed to those shown in Tables 1-1 to 1-4. .. The results are shown in Tables 1-1 to 1-4. The notation of electrolytes is summarized in Table 2.

(Comparative Examples 1 to 3)
Regarding the method for producing an electrochromic device, an electrochromic element was produced and evaluated in the same manner as in Example 1 except that each electrochromic compound and electrolyte was changed to those shown in Table 1-4. The results are shown in Table 1-4. The compounds shown below were used as the electrochromic compounds used in the comparative examples.
<Comparative compound 1>
<Comparative compound 2>
<Comparative compound 3>

<Measurement of anion potential of comparative example>
Similar to the method for measuring the oxidation potential of the anion of the electrochromic compound of the present invention, 1-ethyl-3-methyl-imidazolium bromide was used as the anion of Comparative Compound 1 and Comparative Compound 3, and 1-ethyl was used as the anion of Comparative Compound 2. The oxidation potential of -3-methyl-imidazolium chloride was measured. As a result, 1-ethyl-3-methyl-imidazolium bromide was confirmed to have a current due to an oxidation reaction at a potential 1.1 V higher than the reduction potential of the dication of octylviologen, and 1-ethyl-3-methyl-imidazolium chloride was confirmed to be a viologen. The current value due to the oxidation reaction was confirmed at a potential 1.4 V higher than the reduction potential of. From this, it can be seen that the oxidation potentials of these anions are not higher than the reduction potentials of the dications of Comparative Compounds 1 to 3 by 3.1 V or more.

From the results, it was confirmed that the electrochromic device of the present invention is excellent in transparency, color density, and durability.

Aspects of the present invention are, for example, as follows.
<1> With the first electrode
A second electrode provided so as to face the first electrode at a distance,
On the first electrode, a first electrochromic layer having a conductive or semiconductor nanostructure and an electrochromic compound,
An electrolyte layer containing an electrolyte is provided between the first electrochromic layer and the second electrode.
The electrochromic compound is a compound represented by the following general formula 1.
The electrochromic device is characterized in that the anion of the electrolyte is a monovalent anion having an oxidation potential higher than the reduction potential of the dication in the general formula 1 by 3.1 V or more.
[General formula 1]
In the general formula 1, R ₁ and R ₂ are hydrogen atom, aryl group up to 14 carbon atoms, heteroaryl group up to 14 carbon atoms, branched alkyl group up to 10 carbon atoms, and carbon atom, respectively. Represents an alkenyl group up to several tens, a cycloalkyl group up to ten carbon atoms, or a functional group that can be bonded to a hydroxyl group. R ₃ and R ₄ represent an arylene group having up to 12 carbon atoms which may have an alkylene group having 1 to 10 carbon atoms or a substituent.
In the general formula 1, Z is alkylene, cycloalkylene, and R _7- Y-R ₈ (where R ₇ and R ₈ are independently selected from single bond, alkylene, and cycloalkylene, respectively. Y is selected from arylene, cycloalkylene, heteroarylene, arylene-allylen, and arylene-CR'R''-arylene, where R'and R'' are combined with the carbon to which they are attached. It is selected from divalent groups (forming carbon ring groups). The alkylene, the cycloalkylene, the arylene, the heteroarylene, and the carbocyclic group are halogen, alkyl, alkoxy, alkylthio, hydroxyalkyl, acyloxy, cycloalkyl, aryl, substituted aryl, aryloxy, heteroaryl and Substituted Heteroaryls may be substituted with one or more substituents selected from them. k represents 0 or 1.
In the general formula 1, X ⁻ represents a monovalent anion having an oxidation potential higher than the reduction potential of the dication in the general formula 1 by 3.1 V or more.
In the general formula 1, W ²⁺ represents a dication represented by the following general formula 2.
[General formula 2]
In the general formula 2, o, p, and q each independently represent 0 or 1, and A, B, and C each independently may have a substituent and have 2 to 20 carbon atoms. Represents a group or a heterocyclic group.
<2> The electrochromic device according to <1>, wherein the first electrochromic layer is obtained by adhering the electrochromic compound to the nanostructure.
<3> With the first electrode
A second electrode provided so as to face the first electrode at a distance,
A first electrochromic layer obtained by adhering an electrochromic compound to a conductive or semiconductor nanostructure on the first electrode, and
It has an electrolyte layer between the first electrochromic layer and the second electrode.
An electrochromic device characterized in that the electrochromic compound is a compound represented by the following general formula 1.
[General formula 1]
In the general formula 1, R ₁ and R ₂ are hydrogen atom, aryl group up to 14 carbon atoms, heteroaryl group up to 14 carbon atoms, branched alkyl group up to 10 carbon atoms, and carbon atom, respectively. Represents an alkenyl group up to several tens, a cycloalkyl group up to ten carbon atoms, or a functional group that can be bonded to a hydroxyl group. R ₃ and R ₄ represent an arylene group having up to 12 carbon atoms which may have an alkylene group having 1 to 10 carbon atoms or a substituent.
In the general formula 1, Z is alkylene, cycloalkylene, and R _7- Y-R ₈ (where R ₇ and R ₈ are independently selected from single bond, alkylene, and cycloalkylene, respectively. Y is selected from arylene, cycloalkylene, heteroarylene, arylene-allylen, and arylene-CR'R''-arylene, where R'and R'' are combined with the carbon to which they are attached. It is selected from divalent groups (forming carbon ring groups). The alkylene, the cycloalkylene, the arylene, the heteroarylene, and the carbocyclic group are halogen, alkyl, alkoxy, alkylthio, hydroxyalkyl, acyloxy, cycloalkyl, aryl, substituted aryl, aryloxy, heteroaryl and Substituted Heteroaryls may be substituted with one or more substituents selected from them. k represents 0 or 1.
In the general formula 1, X ⁻ represents a monovalent anion having an oxidation potential higher than the reduction potential of the dication in the general formula 1 by 3.1 V or more.
In the general formula 1, W ²⁺ represents a dication represented by the following general formula 2.
[General formula 2]
In the general formula 2, o, p, and q each independently represent 0 or 1, and A, B, and C each independently may have a substituent and have 2 to 20 carbon atoms. Represents a group or a heterocyclic group.
<4> The electrolyte layer contains an electrolyte and
The electrochromic device according to <3>, wherein the electrolyte anion is a monovalent anion having an oxidation potential higher than the reduction potential of the dication in the general formula 1 by 3.1 V or more.
<5> The anion of the electrolyte in the electrolyte layer is (FSO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (CN) ₄ B ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , and ClO ₄ ^−. The electrochromic element is one or more of the above <1>, <2>, and <4> selected from the above.
<6> From <1>, wherein _{at least one of R 1} and R ₂ in the general formula 1 is any one of a phosphonic acid group, a phosphoric acid group, a carboxylic acid group, a sulfonyl group, a silyl group, and a silanol group. The electrochromic element according to any one of <5>.
<7> In the general formula 1, _{either R 1} or R ₂ is one of a phosphonic acid group, a phosphoric acid group, a carboxylic acid group, a sulfonyl group, a silyl group, and a silanol group.
On the other hand, hydrogen atoms, aryl groups with up to 14 carbon atoms, heteroaryl groups with up to 14 carbon atoms, branched alkyl groups with up to 10 carbon atoms, alkenyl groups with up to 10 carbon atoms, and up to 10 carbon atoms. The electrochromic element according to any one of <1> to <6>, which is any of the cycloalkyl groups of the above.
<8> In the general formula 1, X ⁻ is derived from (FSO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (CN) ₄ B ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , and ClO ₄ ^−. The electrochromic device according to any one of <1> to <7>, which is one or more selected types.
<9> In the general formula 1, X ⁻ is one or more selected from (FSO ₂ ) ₂ N ⁻ and (CF ₃ SO ₂ ) ₂ N ⁻ , whichever is <1> to <8>. The electrochromic element described in the above.
<10> The electrochromic device according to any one of <1> to <9>, wherein ^{X −} in the general formula 1 is (CF ₃ SO ₂ ) ₂ N ^−.
<11> In the general formula 1, W ²⁺ is the electrochromic element according to any one of <1> to <10> represented by the following structural formula 1.
[Structural formula 1]
<12> The electrochromic device according to any one of <1> to <11>, wherein k is 0 in the general formula 1.
<13> In formula 1 R ₃ is represented by the following general formula 3, R ₄ is electrochromic device according to any one of of the following formula 4 of <1> to <12>.
[General formula 3]
[General formula 4]
However, in the general formula 3, m represents an integer of 0 or 1 to 10, n represents an integer of 0 or 1 to 10 in the general formula 4, and m and n may have the same value but are different from each other. You may.
<14> A second electrochromic layer is further provided on the second electrode.
The electrochromic device according to any one of <1> to <13>, which has the electrolyte layer between the first electrochromic layer and the second electrochromic layer.
<15> The electrochromic element according to <14>, wherein the second electrochromic layer contains a polymer obtained by polymerizing a polymerizable material containing a radically polymerizable compound having a triarylamine skeleton.
<16> The electrochromic device according to <15>, wherein the polymerizable material further contains a radically polymerizable compound having a tetraarylbenzidine skeleton.

The electrochromic device according to <1> to <16> can solve the conventional problems and achieve the object of the present invention.

100 Electrochromic element 101 First electrode 102 Second electrode 103 Electrolyte layer 104 First electrochromic layer 105 Second electrochromic layer

JP-A-2017-107153 Japanese Unexamined Patent Publication No. 2008-052172 Special Table 2018-508034 JP-A-2017-206499 Japanese Patent No. 6456964 Special Table 2002-524762

Claims (16)

With the first electrode
A second electrode provided so as to face the first electrode at a distance,
On the first electrode, a first electrochromic layer having a conductive or semiconductor nanostructure and an electrochromic compound,
An electrolyte layer containing an electrolyte is provided between the first electrochromic layer and the second electrode.
The electrochromic compound is a compound represented by the following general formula 1.
An electrochromic device characterized in that the anion of the electrolyte is a monovalent anion having an oxidation potential higher than the reduction potential of the dication in the general formula 1 by 3.1 V or more.
[General formula 1]
In the general formula 1, R ₁ and R ₂ are hydrogen atom, aryl group up to 14 carbon atoms, heteroaryl group up to 14 carbon atoms, branched alkyl group up to 10 carbon atoms, and carbon atom, respectively. Represents an alkenyl group up to several tens, a cycloalkyl group up to ten carbon atoms, or a functional group that can be bonded to a hydroxyl group. R ₃ and R ₄ represent an arylene group having up to 12 carbon atoms which may have an alkylene group having 1 to 10 carbon atoms or a substituent.
In the general formula 1, Z is alkylene, cycloalkylene, and R _7- Y-R ₈ (where R ₇ and R ₈ are independently selected from single bond, alkylene, and cycloalkylene, respectively. Y is selected from arylene, cycloalkylene, heteroarylene, arylene-allylen, and arylene-CR'R''-arylene, where R'and R'' are combined with the carbon to which they are attached. It is selected from divalent groups (forming carbon ring groups). The alkylene, the cycloalkylene, the arylene, the heteroarylene, and the carbocyclic group are halogen, alkyl, alkoxy, alkylthio, hydroxyalkyl, acyloxy, cycloalkyl, aryl, substituted aryl, aryloxy, heteroaryl and Substituted Heteroaryls may be substituted with one or more substituents selected from them. k represents 0 or 1.
In the general formula 1, X ⁻ represents a monovalent anion having an oxidation potential higher than the reduction potential of the dication in the general formula 1 by 3.1 V or more.
In the general formula 1, W ²⁺ represents a dication represented by the following general formula 2.
[General formula 2]
In the general formula 2, o, p, and q each independently represent 0 or 1, and A, B, and C each independently may have a substituent and have 2 to 20 carbon atoms. Represents a group or a heterocyclic group. The electrochromic device according to claim 1, wherein the first electrochromic layer is obtained by adhering the electrochromic compound to the nanostructure. With the first electrode
A second electrode provided so as to face the first electrode at a distance,
A first electrochromic layer obtained by adhering an electrochromic compound to a conductive or semiconductor nanostructure on the first electrode, and
It has an electrolyte layer between the first electrochromic layer and the second electrode.
An electrochromic device characterized in that the electrochromic compound is a compound represented by the following general formula 1.
[General formula 1]
In the general formula 1, R ₁ and R ₂ are hydrogen atom, aryl group up to 14 carbon atoms, heteroaryl group up to 14 carbon atoms, branched alkyl group up to 10 carbon atoms, and carbon atom, respectively. Represents an alkenyl group up to several tens, a cycloalkyl group up to ten carbon atoms, or a functional group that can be bonded to a hydroxyl group. R ₃ and R ₄ represent an arylene group having up to 12 carbon atoms which may have an alkylene group having 1 to 10 carbon atoms or a substituent.
In the general formula 1, Z is alkylene, cycloalkylene, and R _7- Y-R ₈ (where R ₇ and R ₈ are independently selected from single bond, alkylene, and cycloalkylene, respectively. Y is selected from arylene, cycloalkylene, heteroarylene, arylene-allylen, and arylene-CR'R''-arylene, where R'and R'' are combined with the carbon to which they are attached. It is selected from divalent groups (forming carbon ring groups). The alkylene, the cycloalkylene, the arylene, the heteroarylene, and the carbocyclic group are halogen, alkyl, alkoxy, alkylthio, hydroxyalkyl, acyloxy, cycloalkyl, aryl, substituted aryl, aryloxy, heteroaryl and Substituted Heteroaryls may be substituted with one or more substituents selected from them. k represents 0 or 1.
In the general formula 1, X ⁻ represents a monovalent anion having an oxidation potential higher than the reduction potential of the dication in the general formula 1 by 3.1 V or more.
In the general formula 1, W ²⁺ represents a dication represented by the following general formula 2.
[General formula 2]
In the general formula 2, o, p, and q each independently represent 0 or 1, and A, B, and C each independently may have a substituent and have 2 to 20 carbon atoms. Represents a group or a heterocyclic group. The electrolyte layer contains an electrolyte and
The electrochromic device according to claim 3, wherein the anion of the electrolyte is a monovalent anion having an oxidation potential higher than the reduction potential of the dication in the general formula 1 by 3.1 V or more. The anion of the electrolyte in the electrolyte layer is selected from (FSO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (CN) ₄ B ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , and ClO ₄ ^−. The electrochromic device according to any one or more of claims 1, 2, and 4. _{Any of claims 1 to 5, wherein at least one of R 1} and R ₂ in the general formula 1 is any one of a phosphonic acid group, a phosphoric acid group, a carboxylic acid group, a sulfonyl group, a silyl group, and a silanol group. The electrochromic element described in. In the general formula 1, _{either R 1} or R ₂ is one of a phosphonic acid group, a phosphoric acid group, a carboxylic acid group, a sulfonyl group, a silyl group, and a silanol group.
On the other hand, hydrogen atoms, aryl groups with up to 14 carbon atoms, heteroaryl groups with up to 14 carbon atoms, branched alkyl groups with up to 10 carbon atoms, alkenyl groups with up to 10 carbon atoms, and up to 10 carbon atoms. The electrochromic element according to any one of claims 1 to 6, which is any of the cycloalkyl groups of the above. In the general formula 1, X ⁻ is selected from (FSO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (CN) ₄ B ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , and ClO ₄ ^−. The electrochromic device according to any one of claims 1 to 7, which is a species or a plurality of species. The electrochromic according to any one of claims 1 to 8, ^{wherein X −} in the general formula 1 is one or more selected from (FSO ₂ ) ₂ N ⁻ and (CF ₃ SO ₂ ) ₂ N ^−. element. The electrochromic device according to any one of claims 1 to 9, ^{wherein X −} in the general formula 1 is (CF ₃ SO ₂ ) ₂ N ^−. The electrochromic device according to any one of claims 1 to 10, ^{wherein W 2+} in the general formula 1 is represented by the following structural formula 1.
[Structural formula 1]
The electrochromic device according to any one of claims 1 to 11, wherein k is 0 in the general formula 1. The electrochromic device according to any one of claims 1 to 12, wherein R ₃ is represented by the following general formula 3 and R _{4 is represented by the following general formula 4 in the general formula 1.}
[General formula 3]
[General formula 4]
However, in the general formula 3, m represents an integer of 0 or 1 to 10, n represents an integer of 0 or 1 to 10 in the general formula 4, and m and n may have the same value but are different from each other. You may. A second electrochromic layer is further provided on the second electrode.
The electrochromic device according to any one of claims 1 to 13, which has the electrolyte layer between the first electrochromic layer and the second electrochromic layer. The electrochromic element according to claim 14, wherein the second electrochromic layer contains a polymer obtained by polymerizing a polymerizable material containing a radically polymerizable compound having a triarylamine skeleton. The electrochromic device according to claim 15, wherein the polymerizable material further contains a radically polymerizable compound having a tetraarylbenzidine skeleton.