JP6808363B2 - Electrochromic elements and their driving methods, as well as optical filters, lens units, imaging devices and window materials - Google Patents

Description

The present invention relates to an electrochromic element and a driving method thereof, and an optical filter, a lens unit, an image pickup device, and a window material using the electrochromic element.

An EC element using an electrochromic (hereinafter, may be abbreviated as "EC") material whose optical absorption properties (absorption wavelength, absorbance) of a substance are changed by an electrochemical redox reaction is a display device. It is applied to variable reflectance mirrors, variable transmission windows, etc. Among EC materials, organic electrochromic compounds are being actively developed because they can be designed and changed in absorption wavelength and can achieve high color-decoloring contrast.

In such an EC device, suppressing changes in optical characteristics over time is one of the greatest issues. In Patent Document 1, in a complementary EC element in which an EC material is dissolved in an electrolyte, a non-EC material that is more easily oxidized than an anodic EC material and a material that is more easily reduced than a cathodic EC material are used. Is disclosed. These materials will be referred to as "redox buffer" hereafter.

In the EC element of Patent Document 1, the oxidant or reduced form of the redox buffer is more stable than the oxidized form of the anodic EC material and the reduced form of the cathodic EC material, which are colored bodies. Therefore, even if a charge imbalance occurs during the decoloring operation, as long as the charge amount of the redox buffer can be covered, the colored body of the EC material does not remain, but the oxide or reduction of the corresponding redox buffer. The body produces. Since this redox buffer is non-EC, even if these oxides or reductions are produced, the redox reaction does not affect the light transmittance. In other words, this redox buffer imparts a non-variable color charge balance region so that the charge imbalance of the EC element does not directly lead to decolorization failure.

U.S. Pat. No. 6,188,505

However, in Patent Document 1, the redox buffer is more easily oxidized than the anodic EC material or is more easily reduced than the cathodic EC material, and therefore is more likely to react electrically than the EC material. Therefore, in a normal coloring operation of an EC element, it reacts prior to (at least equal to or more than) the EC material. As a result, as compared with the case where the redox buffer is not used, there is a problem that a useless current that does not contribute to coloring flows, power consumption increases, and the response speed decreases.

Further, as in Patent Document 1, even if a redox buffer is used, the charge imbalance between the display electrodes is not eliminated. That is, it does not affect the charge balance between the display electrodes only by reducing the colored matter of the EC material (= instead, the oxidized / reduced body of the redox buffer that does not fade is generated). When charge imbalance occurs in a complementary EC device, the ratio of colored bodies of anodic EC material / cathodic EC material will change. Specifically, the color ratio of the material having the opposite polarity of the material remaining due to the charge imbalance may be smaller than the color ratio of the material remaining due to the charge imbalance. As an example, when the EC element is colored from the state of charge imbalance in which the colored body of the cathodic EC material remains, it is caused by the anode material as compared with the state in which charge imbalance does not occur. The coloring ratio to be applied is smaller than the coloring ratio due to the cathode material. As a result, the actual absorption spectrum changes from the absorption spectrum assumed at the time of design, which is not preferable because it appears as a discoloration of the absorption color of the EC element. In Patent Document 1, the redox buffer takes on the charge of the remaining oxidant of the anode material or the reductant of the cathode material during the decoloring operation due to the charge imbalance, so that the polarity of one of the anode and the cathode is colored. Suppress remaining. However, since the charge imbalance itself between the display electrodes is not corrected, the shift of the colorant ratio of the anodic EC material / cathodic EC material is not corrected. In other words, even if a charge imbalance occurs between the display electrodes, it only suppresses the color from being seen during the decoloring operation, and during the coloring operation, the ratio of the anode material and the cathode material changes due to the charge imbalance. Will have a different colored state.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to correct an imbalance of electric charges that can be generated, and to suppress decolorization defects (color residue) at the time of decolorization. Another object of the present invention is to provide an electrochromic element having excellent spectral reproducibility during a coloring operation.

The first aspect of the electrochromic element of the present invention comprises a first electrode, a second electrode, and a third electrode, and at least one of the first electrode and the second electrode. An electrochromic element having one of them transparent and having an electrolyte, an anodic organic electrochromic compound, and a cathodic oxidation-reducing substance between the first electrode and the second electrode. hand,
The electrolyte is arranged between the first electrode and the third electrode, and at least one of the second electrode and the third electrode.
The third electrode further comprises a non-electrochromic redox material.
The redox substance of the third electrode is more easily oxidized than the reduced product of the anodic organic electrochromic compound.

A second aspect of the electrochromic element of the present invention comprises a first electrode, a second electrode, and a third electrode, and at least one of the first electrode and the second electrode. An electrochromic element having one of them transparent and having an electrolyte, a cathodic organic electrochromic compound, and an anodic oxidation-reducing substance between the first electrode and the second electrode. hand,
The electrolyte is arranged between the first electrode and the third electrode, and at least one of the second electrode and the third electrode.
The third electrode further comprises a non-electrochromic redox material.
The oxide of the redox substance contained in the third electrode is more easily reduced than the oxide of the cathodic organic electrochromic compound.

A third aspect of the electrochromic element of the present invention comprises a first electrode, a second electrode, and a third electrode, and at least one of the first electrode and the second electrode. An electrochromic element in which one of them is transparent and has an electrolyte, an anodic organic electrochromic compound, and a cathodic organic electrochromic compound between the first electrode and the second electrode. There,
The electrolyte is arranged between the first electrode and the third electrode, and at least one of the second electrode and the third electrode.
The third electrode has a redox substance and
The redox substance of the third electrode is more easily oxidized than the redox compound of the anodic organic electrochromic compound.
The oxide of the redox substance contained in the third electrode is more easily reduced than the oxide of the cathodic organic electrochromic compound.

According to the present invention, an electrochromic device capable of correcting the imbalance of electric charges that can occur, suppressing decolorization defects (color residue) during decolorization, and having excellent spectral reproducibility during coloring operation. Can be provided.

It is a figure explaining the concept of charge balance / imbalance. It is sectional drawing which shows the example of the Embodiment in the EC element of this invention. It is a top view of the EC element of this invention. It is a schematic diagram which shows the example of the control circuit of the EC element of this invention. (A) is a figure which shows the absorption spectrum of the EC element which does not correspond to this invention, and (b) is a figure which shows the absorption spectrum of the EC element of this invention. It is a schematic diagram which shows the example of the embodiment in the image pickup apparatus of this invention. It is a schematic diagram which shows the example of the embodiment in the window material of this invention, (a) is the perspective view, (b) is the XX'cross-sectional view of (a). It is a schematic diagram which shows the EC element produced in Example 1. It is a schematic diagram which shows the EC element produced in Example 2. It is a schematic diagram which shows the EC element produced in Example 3.

The electrochromic element (EC element) of the present invention has a first electrode, a second electrode, and a third electrode. In the present invention, at least one of the first electrode and the second electrode is transparent. In the present invention, an electrolyte and an anodic organic electrochromic compound or a cathodic organic electrochromic compound are provided between the first electrode and the second electrode. In the present invention, at least two kinds of redox substances (including an organic electrochromic compound) are provided between the first electrode and the second electrode. Here, the two types of redox substances contained between the first electrode and the second electrode are specifically any of the combinations shown in the following (i) to (iii).
(I) Anodic organic electrochromic compounds and cathodic oxidation-reducing substances (ii) Cathodic organic electrochromic compounds and anodic oxidation-reducing substances (iii) Anodic organic electrochromic compounds and cathodic organic electro Chromic compound

In the present invention, the third electrode can be electrically connected to at least one of the first electrode and the second electrode via an electrolyte. In the present invention, the third electrode has a redox substance. When an anodic organic electrochromic compound (EC material) is contained between the first electrode and the second electrode, the redox substance reducer of the third electrode is the anodic organic electrochromic. It is more easily oxidized than the reduced form of the compound. On the other hand, when a cathodic organic electrochromic compound (EC material) is contained between the first electrode and the second electrode, the oxide of the redox substance contained in the third electrode is the cathodic organic electro. It is more easily reduced than the oxide of chromic compounds.

In the present invention, an anodic redox substance and a cathodic redox substance are used, and at least one of these redox substances is an EC material, which is called a complementary type. Improve color defects. The concept of charge balance / imbalance will be described later.

1. 1. Redox substance In the present invention, the redox substance is a compound capable of repeatedly causing a redox reaction in a predetermined potential range. The redox substance includes both an inorganic compound and an organic compound, but both can be used in the present invention without particular limitation. Among them, redox substances of organic compounds are preferably used from the viewpoint of compatibility with the usage environment of the EC material used.

In the following description, the redox substance may be described as, for example, "anodic redox substance" or "cathodic redox substance". Here, the anodic redox substance is a substance that is normally in a reduced state when the device is not driven, but is in an oxidized state when the device is driven (particularly colored). The cathodic redox substance is a substance that is normally in an oxidized state when the device is not driven, but is in a reduced state when the device is driven (particularly colored).

2. 2. Organic Electrochromic (EC) Material In the present invention, the organic electrochromic (EC) material is a kind of redox substance, and the light absorption characteristic changes in the target light wavelength region of the device by the redox reaction. Is. The electrochromic material includes both an organic compound and an inorganic compound, but in the following description, the organic electrochromic material will be referred to as an "EC material". Further, the light absorption characteristic referred to here is typically a light absorption state and a light transmission state, and the EC material is a material that switches between the light absorption state and the light transmission state.

By the way, in the following description, the EC material may be described as "anodic EC material" or "cathodic EC material". Here, the anodic EC material refers to a material that changes from a light transmitting state to a light absorbing state by an oxidation reaction in which electrons are removed from the EC material in the target light wavelength region of the element. Further, the cathodic EC material refers to a material that changes from a light transmitting state to a light absorbing state by a reduction reaction in which electrons are donated to the EC material in the light wavelength region targeted by the device.

3. 3. Oxidants, reducers Oxidizers and reducers, which are terms used for redox substances and EC materials, will be described below. In the following description, the redox substance and the oxidant of the EC material refer to those that are reduced to the reduced substance by the reduction reaction of one or more electrons at the electrode when the corresponding reduction reaction proceeds reversibly. On the other hand, a redox substance or a reduced product of an EC material means a product that is oxidized to an oxidized product by an oxidation reaction of one or more electrons at an electrode when the corresponding oxidation reaction proceeds reversibly.

Depending on the literature, as an expression indicating the state of the redox substance and the EC material, there is also an expression of an oxidant, a neutral substance, and then a reduced substance (or vice versa). However, in the following description, basically, it is recognized that the reduced product is produced when the oxidant is reduced, and the oxidant is produced when the reduced product is oxidized. , Oxidate and reducer are adopted. For example, ferrocene having a divalent iron (neutral substance as a whole molecule) is a reduced form of ferrocene (anodic redox substance) when ferrocene functions as an anodic redox substance. When this reduced product is oxidized to make iron trivalent, it is an oxidized product of ferrocene (anodic redox substance). When the dication salt of viologen functions as a cathodic EC material, the dication salt is an oxide of the cathodic EC material. The monocationic salt obtained by reducing the dication salt by one electron is a reduced product of a cathodic EC material.

4. Electrolyte In the present invention, the electrolyte is not limited to the electrolyte itself, but also includes the concept of an electrolytic solution prepared by dissolving an electrolyte in a solvent. In the present invention, the electrolyte also includes a solution obtained by dissolving a salt compound in a solvent, an ionic liquid, a gel electrolyte, a polymer electrolyte and the like.

5. Redox substance contained in the third electrode The third electrode constituting the EC element of the present invention contains a redox substance. Here, the fact that the third electrode has a redox substance means that the redox substance is directly or indirectly immobilized on the third electrode. Here, when the redox substance is directly immobilized on the third electrode, the redox substance is immobilized on the third electrode by a physical or chemical factor without interposing other substances. It is in a state. On the other hand, when the redox substance is indirectly immobilized on the third electrode, the redox substance is physically or chemically immobilized on the third electrode via, for example, a film-like substance. It is in a state of being.

In any case, it is preferable that the redox substance contained in the third electrode is in a state where electric charges can be exchanged with the third electrode. In the present invention, the third electrode is an electrode capable of transferring and receiving electric charges to and from the EC material contained in the electrolyte, and also capable of transferring and receiving electric charges to and from an external circuit.

6. Charge Balance / Imbalance The concept of charge balance / imbalance will be described below with reference to the drawings. FIG. 1 is a diagram illustrating the concept of charge balance / imbalance. Note that FIG. 1 targets a complementary EC element. FIG. 1 shows a first electrode 1 which is an anode and a second electrode 2 which is a cathode. Further, in FIG. 1, A is a reduced product (colored state) of the anodic EC material, and A ⁺ is an oxidized product (colored state) of the anodic EC material. Further, in FIG. 1, C is an oxidant of the cathodic EC material (decolorized state), and C ⁻ is a reduced product of the cathodic EC material (colored state).

FIG. 1A is a diagram showing a coloring process of the EC element. When a coloring voltage is applied between the anode (first electrode 1) and the cathode (second electrode 2), the oxidation reaction of the anodic EC material shown in (α) below proceeds at the first electrode 1. Then, at the second electrode 2, the reduction reaction of the cathodic EC material shown in the following (β) proceeds.
^{A → A + + e - (} α)
^{C + e - → C - (} β)

As these reactions proceed, the EC cell becomes colored.

FIG. 1B is a diagram showing a decoloring process which is a process opposite to the coloring process. When the EC cell is decolorized, a decoloring voltage (for example, 0V that short-circuits between the first electrode 1 and the second electrode 2) is applied between the first electrode 1 and the second electrode 2. By applying the voltage, the reverse reaction of the reaction shown in FIG. 1 (a) proceeds as shown by the arcuate arrow in FIG. 1 (b). As a result, the anodic EC material is in the reduced state A and the cathodic EC material is in the oxidized state C, and the colored EC material can be returned to the decolorized state.

When the reactions shown in FIGS. 1A and 1B are repeated, the charge balance of the EC element is normal, and the element normally repeats color removal.

On the other hand, when the EC element is driven, the charge balance may be lost because some steps other than the normal coloring / erasing step are performed. There are several types of causes, but here, the deterioration of the oxidant (A ⁺ ) of the anodic EC material will be taken up as an example and described with reference to FIG. 1 (c). When the oxidant A ^{+ of} the anodic EC material colored through the normal coloring process deteriorates and cannot react at the first electrode 1, the second electrode 2 also has a cathodic property. reduced form of EC material C ^- is lose recipient of the electronic, no longer able to react. In the following description, such a phenomenon is referred to as charge imbalance, that is, charge imbalance. Result imbalance charge occurs, the EC element, although the cathode of the EC material is normal, coloring of the cathode of the EC material C ^- is to exhibit decoloring defects remaining.

As a cause of charge imbalance, there is an irreversible electron transfer reaction (particularly, electrode reaction) of the substrate constituting the redox reaction. Specific examples thereof include impurities (derived from EC materials, environmental impurities (oxygen, water, etc.), derived from sealants), chemical reactions between radicals, and the like. Examples include the irreversible reduction reaction of oxygen that has entered as an impurity to leave the colored body of the anode material, and the irreversible oxidation reaction of the sealant-containing component to leave the colored body of the cathode material. ..

7. EC element FIG. 2 is a schematic cross-sectional view showing an example of an embodiment of the EC element of the present invention. The EC element 10 of FIG. 2 has a substrate (first substrate 7) having a first electrode 1, a third electrode 3, a second electrode 2, and a third electrode 3. It has a substrate (second substrate 8). In the EC element 10 of FIG. 2, an electrolyte 4 is arranged between the first electrode 1 and the second electrode 2, and the electrolyte 4 is the first electrode 1, the second electrode 2, and the second electrode 2. It is in contact with the third electrode 3. The electrolyte 4 is preferably held isolated from the outside by a sealing material 5. Further, in the present invention, for the purpose of limiting the transport of substances between the first electrode 1 and the second electrode 2 and the third electrode 3, the partition wall 6 shown in FIG. 2 is provided as necessary. It may be provided between the first electrode 1 and the second electrode 2 and the third electrode 3. Further, the EC element of the present invention has an anodic redox substance and a cathodic redox substance between the first electrode 1 and the second electrode 2. The anodic redox substance and the cathodic redox substance contained between the first electrode 1 and the second electrode 2 may be dissolved in the electrolyte 4, respectively, or the first electrode 1 or It may be immobilized on the second electrode 2. Further, at least one of the anodic redox substance and the cathodic redox substance contained between the first electrode 1 and the second electrode 2 is an EC material.

Hereinafter, the components of the electrochromic device of the present invention will be described.

(1) Substrate 7, 8 / Electrodes 1, 2, 3
(1-1) Substrates 7, 8
Examples of the substrate (7, 8) constituting the EC element 10 include a transparent substrate such as glass or a polymer compound.

(1-2) First electrode 1, second electrode 2
At least one of the first electrode 1 and the second electrode 2 is a transparent electrode. Here, "transparent" means that the corresponding electrode transmits light, and the light transmittance is preferably 50% or more and 100% or less. Since at least one of the first electrode 1 and the second electrode 2 is a transparent electrode, light is efficiently taken in from the outside of the EC element and interacts with the molecule of the EC material to optically capture the EC molecule. This is because the characteristics can be reflected in the emitted light. Further, the "light" referred to here is light in the wavelength region targeted by the EC element. For example, if the EC element is used as a filter for an image pickup device in the visible light region, the target is light in the visible light region, and if it is used as a filter for an image pickup device in the infrared region, the target is light in the infrared region. Become.

As the transparent electrode, a transparent conductive oxide or a conductive layer such as dispersed carbon nanotubes is formed on the above-mentioned substrate (7, 8), or a transparent electrode is partially formed on the transparent substrate (7, 8). A transparent electrode on which a metal wire is arranged, or a combination thereof can be used.

Examples of the transparent conductive oxide include tin-doped indium oxide (ITO), zinc oxide, gallium-doped zinc oxide (GZO), aluminum-doped zinc oxide (AZO), tin oxide, antimony-doped tin oxide (ATO), and fluorine-doped tin oxide. (FTO), niobium-doped titanium oxide (TNO) and the like. Among these, FTO is preferable from the viewpoint of heat resistance (from the viewpoint of correspondence to the firing process when forming the porous electrode), reduction resistance and conductivity, and ITO is preferable from the viewpoint of conductivity and transparency. It is preferably used. When the electrode is formed of a transparent conductive oxide, the film thickness is preferably 10 nm to 10000 nm. In particular, a layer of a transparent conductive oxide having a film thickness of 10 nm to 10000 nm and being a layer of FTO or ITO is preferable. This makes it possible to achieve both high permeability and chemical stability.

The transparent conductive oxide layer may have a structure in which sublayers of the transparent conductive oxide are stacked. This makes it easier to achieve high conductivity and high transparency.

The metal wire that can be arranged on the substrate (7, 8) is not particularly limited, but a wire made of an electrochemically stable metal material such as Ag, Au, Pt, Ti, etc. is preferably used. Further, as the arrangement pattern of the metal wires, a grid shape is preferably used. The electrode having a metal wire is typically a flat electrode, but a curved electrode can also be used if necessary.

Among the first electrode 1 and the second electrode 2, as the electrode other than the above-mentioned transparent electrode, a preferable one is selected depending on the application of the EC element. For example, when the EC element 10 of FIG. 2 is a transmissive EC element, it is preferable that both the first electrode 1 and the second electrode 2 are the above-mentioned transparent electrodes. On the other hand, when the EC element 10 of FIG. 2 is a reflection type EC element, one of the first electrode 1 and the second electrode 2 is the above-mentioned transparent electrode, and the other is an electrode that reflects incident light. And. On the other hand, by forming a reflective layer or a scattering layer between the electrodes, it is possible to improve the degree of freedom in the optical characteristics of electrodes other than the above-mentioned transparent electrodes. For example, when a reflection layer or a scattering layer is introduced between the electrodes, an opaque electrode or an electrode that absorbs light can be used as an electrode behind the electrode without affecting the emitted light.

Regardless of the form of the EC element of the present invention, the constituent material of the first electrode 1 and the second electrode 2 stably exists in the operating environment of the EC element, and the voltage from the outside is applied. A material capable of rapidly advancing the redox reaction in response to application is preferably used.

In the present invention, the distance between the first electrode 1 and the second electrode 2 (distance between electrodes) is preferably 1 μm or more and 500 μm or less. When the distance between the electrodes is large, it is advantageous in that a sufficient amount of EC material can be arranged to effectively function as an EC element. On the other hand, when the distance between the electrodes is short, it is advantageous in that a fast response speed can be achieved.

(1-3) Third electrode 3
The EC element of the present invention has a third electrode 3 in addition to the first electrode 1 and the second electrode 2. As described in "Charge Balance / Imbalance", an anodic redox substance and / or a cathodic redox substance are used simultaneously, and one of these redox substances is an EC material. In the EC element of the above, when a charge imbalance state occurs, it may be perceived as a decolorization failure regardless of whether the charge is anodic or cathodic. In such a case, even if the voltage applied between the first electrode 1 and the second electrode 2 is set to a voltage having a polarity opposite to that at the time of coloring, this decolorization failure (remaining disappearance) may be suppressed. , The EC material of the opposite polarity is colored or the redox substance of the opposite polarity reacts, but it is not an effective suppression measure. The "EC material of opposite polarity" here is a cathodic EC material if the remaining object is an anodic EC material, and is an anodic EC material if the remaining object is a cathodic EC material. It is an EC material. The "opposite polarity redox substance" is a cathodic redox substance if the remaining object is an anodic EC material, and is an anodic if the remaining object is a cathodic EC material. It is a redox substance.

Therefore, in the present invention, using the third electrode 3 having a redox substance, the redox reaction that occurs at the time of color loss in the EC layer provided between the first electrode 1 and the second electrode 2 At that time, it was decided to adjust the amount of charge used in the redox reaction passing through both electrodes (1 and 2). The adjustment of the amount of electric charge is called the adjustment of the electric charge balance, that is, the electric charge rebalancing.

In the present invention, as the third electrode 3, an electrode having a redox substance necessary for performing charge rebalancing is used. As the redox substance contained in the third electrode 3, an inorganic compound or an organic compound can be used without particular limitation as long as it is a compound capable of repeating the redox reaction in a desired potential range. Among them, organic compounds are preferably used from the viewpoint of compatibility with the usage environment of the EC material used in combination. Further, in the present invention, the redox substance contained in the third electrode 3 may be one kind or two or more kinds.

It is preferable that the redox state of the redox substance possessed by the third electrode 3 is a state in which the oxide / reduced body is mixed. This can be explained as follows. When the redox state of the redox substance possessed by the third electrode 3 is only the oxidant and only the redox, the redox substance has a polarity that causes either anodic or cathodic charge imbalance. The charge can be corrected. In this case, if the total amount of the redox substances is the same, it is preferable that the charge imbalance of the polarity on one side can be corrected to a large extent. On the other hand, in the case where the oxidant / reducer is mixed, the redox substance can be corrected even if the charge has a polarity that causes an anodic / cathodic charge imbalance. Is preferable. The following method can be used as a method for forming a state in which an oxidized substance / a reduced substance is mixed. In any of the following cases, the method of fixing the redox substance in a state where the oxidant / reducer is mixed from the beginning and the method of fixing the redox substance of the oxidant or the reducer to the carrier once are then fixed. , Each can be formed by partial reduction or oxidation.
1. 1. Anodic / cathodic redox substances are used as the plurality of redox substances. In this case, it is preferable that a redox substance corresponding to the anodic EC material and a redox substance corresponding to the cathodic EC material can be prepared, respectively.
2. 2. A state in which an oxidant / reduced substance of one type of redox substance is mixed. In this case, it is preferable that the number of types of redox substances to be prepared is small.

The redox substance contained in the third electrode 3 may be an EC-based redox substance or a non-EC-based redox substance. If the third electrode 3 is present in the optical path of light incident on the EC element 10, a non-EC redox substance is used in order to reduce the influence of light absorption by the redox substance. Is preferable. On the other hand, when the third electrode 3 is arranged outside the optical path of the light incident on the EC element 10, if an EC redox substance is used, the charge depends on the degree of coloring due to the EC property of the redox substance. It is preferable because it is possible to detect the degree of rebalancing.

As the redox substance contained in the third electrode 3, for example, a metal complex compound can be mentioned. Specifically, a metal complex in which the metal ion is Os, Fe, Ru, Co, Cu, Ni, V, Mo, Cr, Mn, Pt, Rh, Pd, Ir or the like can be mentioned. More specifically, a metallocene compound, a metal complex having a heterocyclic compound as a ligand, Prussian blue, and the like can be mentioned. Examples of the heterocyclic compound that serves as a ligand for the metal complex include bipyridine, terpyridine, and phenanthroline. Further, as the redox substance contained in the third electrode 3, an EC material, particularly an EC material described later, can be preferably used.

The relationship between the redox substance contained in the third electrode 3 and the EC material contained between the first electrode 1 and the second electrode 2 can be explained as follows. When an anodic EC material is contained, the redox substance reduced product of the third electrode 3 is more easily oxidized than the redox product of the anodic EC material. When a cathodic EC material is included, the redox substance oxidant possessed by the third electrode 3 is more likely to be reduced than the oxidant of the cathodic EC material. When both the anodic EC material and the cathodic EC material are included, the redox substance of the third electrode 3 is more easily oxidized than the redox material of the anodic EC material, and the third electrode 3 has a third electrode. The redox substance oxidant of the electrode 3 is more easily reduced than the oxidant of the cathodic EC material.

The reason why this relationship is important is explained below. When the charge balance of the EC element is lost, basically, it is lost to either the anode side or the cathode side. If the charge balance is lost to the anode side (the anodic EC material remains colored even when the element is in a normal decolorized state), electrons are supplied to the oxidant, which is the colorant of the anodic EC material. The charge will be rebalanced. In this case, in order to rebalance the charge by the redox substance possessed by the third electrode 3, the redox substance possessed by the third electrode 3 is more than the redox substance of the anodic EC material. A relationship that is easily oxidized is required. On the other hand, when the charge balance is lost to the cathode side (the cathode EC material remains colored even when the device is in a normal decolorized state), electrons are transferred from the reduced body which is the colored body of the cathode EC material. It will be removed and the charge will be rebalanced. In this case, in order to rebalance the charge by the redox substance of the third electrode 3, the redox substance of the third electrode 3 is more reduced than the redox of the cathodic EC material. It is necessary to have a relationship that is easy to be done.

Further, the redox substance contained in the third electrode 3 is not in a state of being dissolved in the electrolyte 4 (included together with the electrolyte 4 between the first electrode 1 and the second electrode 2), but the third electrode. The following effects are obtained by setting the state of 3 to have (immobilize). By having (immobilizing) the third electrode 3, the oxidation is usually carried out on the first electrode 1 or the second electrode 2 which drives the EC element, that is, promotes the electrochemical reaction in the electrode of the EC material. The reducing substance never reaches. Therefore, the redox substance does not consume the electric charge that should be originally used for the reaction of the EC material. However, this means that the redox of the redox material is more likely to be oxidized than the redox of the anodic EC material and / or the redox of the redox is more likely to be reduced than the oxide of the cathodic EC material. That is, the condition required by the present invention is a prerequisite. This is because, in other words, the above conditions are such that when an anodic EC material and / or a cathodic EC material is to undergo a coloring reaction, the reduced and / or oxidized bodies of the redox substance are the respective EC materials. This is because it means that it is more responsive than. That is, if the redox substance of the third electrode 3 reaches the other electrodes (1, 2), the redox or oxidant of the redox substance is more likely to react than the decolorizer of the EC material. Therefore, the electric charge that should be easily used for the reaction of the EC material is consumed. This is not preferable because an increase in the electric charge that does not contribute to coloring causes a decrease in the color transfer contrast of the EC element, an increase in the amount of electric charge (electric power) required for driving, and a decrease in the response speed of the EC element. Further, when the redox substance directly moves electrons with the colored body of the EC material to decolorize it, if the redox substance is dissolved in the electrolyte 4, the EC material moves due to the movement in the electrolyte 4. The probability of collision between the colored substance and the redox substance increases. As a result, the coloring density of the EC material is lowered. This is also not preferable because it causes a decrease in the color-decoloring contrast of the element, an increase in the amount of charge (electric power), and a decrease in the response speed. Further, the redox substances include many materials having EC properties. When these EC-based redox substances are dissolved in the electrolyte 4, the redox reaction of the redox substances changes the light absorption characteristics incident on the EC element, so that the color and transmission of the EC element are transmitted. It is not preferable because it affects the rate and the like. This can be prevented by arranging the third electrode 3 to have a redox substance and the third electrode 3 to be out of the optical path of the light passing through the EC element.

In the present invention, when the EC element 10 contains an anodic EC material, the redox substance reduced body of the third electrode 3 is more easily oxidized than the redox material of the anodic EC material. Further, when the EC element 10 contains a cathodic EC material, the redox substance oxidant of the third electrode 3 is more likely to be reduced than the oxidant of the cathodic EC material. A method for determining this will be described below.

(1-3a) Method by Direct Electron Transfer Reaction The method described below is a method in which an oxidant of an anodic EC material or a reduced product of a cathodic EC material is brought into direct contact with a corresponding redox substance. Specifically, the corresponding redox substance is put into the electrolyte in which the oxidant of the anodic EC material or the reductant of the cathodic EC material is dissolved. At this time, if included anode of EC material in the electrolyte is a reduced form of the redox substance, if it contains the cathode of the EC material at least put oxidant oxidation reducing substances in the electrolyte. If the colored body, that is, the oxidant of the anodic EC material or the reduced product of the cathodic EC material is decolorized as a result of adding the redox substance, the following matters are found. That is, it is shown that when the anodic EC material is decolorized, electrons are transferred from the redox substance to the oxidant of the EC material, and the anodic EC material becomes the reducer. This means that the redox substance of the third electrode 3 is more easily oxidized than the redox substance of the anodic EC material. It is shown that when the cathodic EC material is decolorized, electron transfer occurs from the reduced body of the EC material to the oxidized body of the redox substance, and the cathodic EC material becomes the oxidized body. This means that the oxidant of the redox substance contained in the third electrode 3 is more easily reduced than the oxidant of the cathodic EC material. Further, when the redox substance contained in the third electrode 3 is EC-like, the decolorization and color change of the EC material can be confirmed. The decolorization of the EC material referred to here is the decolorization of the EC material that the third electrode 3 does not have. The color change of the EC material is a change in absorption of the EC redox substance possessed by the third electrode 3.

(1-3b) Electron transfer reaction method (direct method, via third electrode 3)
The method described below is a method of contacting an electrolyte containing an oxidant of an anodic EC material or a reducer of a cathodic EC material with a third electrode having a redox substance. Specifically, an electrolyte in which an oxidant of an anodic EC material or a reductant of a cathodic EC material is dissolved is brought into contact with a third electrode having a corresponding redox substance. As a result, if the colored body, that is, the oxidized product of the anodic EC material or the reduced product of the cathodic EC material is decolorized, it will be described below in addition to the direct electron transfer reaction described in (1-3a). It can be said that the electron transfer reaction has proceeded through the electrode. Specifically, in the case of the anodic EC material, electron transfer occurs from the reduced body of the redox substance possessed by the third electrode 3 to the third electrode 3, and the anodic EC material is the third electrode. By receiving an electron from 3, it changes from an oxidant (colored state) to a reduced body (decolorized state). The occurrence of this reaction means that the redox material of the third electrode 3 is more easily oxidized than the redox material of the anodic EC material. On the other hand, in the case of a cathodic EC material, electron transfer from the third electrode 3 to the oxidant of the redox substance possessed by the third electrode 3 and electron transfer from the cathodic EC material to the third electrode 3 Occurs. As a result, the cathodic EC material changes from a reduced form (colored state) to an oxidized form (decolorized state). The occurrence of this reaction means that the oxidant of the redox substance contained in the third electrode 3 is more easily reduced than the oxidant of the cathodic EC material. When the redox substance contained in the third electrode 3 has EC property, the decolorization and color change of the EC material can be confirmed in the same manner as in (1-3a).

(1-3c) Method by Measuring Redox Potential The method described below is a method for comparing the ease of oxidation or reduction depending on the redox potential in the electrode reaction of an EC material or a redox substance. Here, the redox potential can be determined by electrochemical measurement. For example, it can be evaluated by measuring cyclic voltanmograms of EC materials and redox substances.

In this measurement, the half-wave potential of the reversible redox reaction of the redox substance possessed by the third electrode 3 is higher than the half-wave potential of the redox reaction corresponding to the oxidation reaction in which the anodic EC material is reversibly colored. The fact that the potential is on the negative side means the following. That is, it means that the redox substance of the redox substance contained in the third electrode 3 is more easily oxidized than the redox substance of the anodic EC material. Further, in this case, the following formula (I) is satisfied between the redox potential E _EC (A) of the anodic EC material and the redox potential E _RO of the redox substance possessed by the third electrode 3. Is preferable.
E _RO <E _EC (A) (I)

The half-wave potential of the reversible redox reaction of the redox substance of the third electrode 3 is on the positive side of the half-wave potential of the redox reaction corresponding to the reduction reaction in which the cathodic EC material is reversibly colored. Being means the following. That is, it means that the oxidant of the redox substance contained in the third electrode 3 is more easily reduced than the oxidant of the cathodic EC material. Further, in this case, the following formula (II) is satisfied between the redox potential E _EC (C) of the cathodic EC material and the redox potential E _RO of the redox substance possessed by the third electrode 3. Is preferable.
E _RO > E _EC (C) (II)

Further, when the EC element contains an anodic EC material and a cathodic EC material, it is particularly preferable that the formulas (I) and (II) are satisfied. That is, the oxidation-reduction potential E _EC of the anode of the EC material (A), the redox potential of the cathode of the EC material E _EC (C), the redox potential of the redox substance third electrode 3 has E _RO It is particularly preferable that the following formula (III) is satisfied between the two.
E _EC (C) <E _RO <E _EC (A) (III)

The electrodes used when performing cyclic voltanmogram measurement will be described below. As the working electrode, the same electrode as that used in the EC element can be used. For example, if the electrode of the EC element is ITO, ITO can be used. As the counter electrode, it is preferable to use a platinum electrode having a sufficient area. The third electrode constituting the EC element of the present invention can be used as it is. Further, as the solvent and support used for the cyclic voltanmogram measurement, it is preferable to use the solvent used for the EC device. The running speed of the voltanmogram is preferably 20 mVs ^{-1 to} 200 mVs ^-1 .

The ease of oxidation or reduction can be measured and evaluated by any of the above three methods, but in particular, the method (1-3b) (method by electron transfer reaction via an electrode) is simple and direct. It is most preferable because the effect can be observed.

The redox substance contained in the third electrode 3, the anodic redox substance (including the EC material) contained between the first electrode 1 and the second electrode 2, and the cathodic redox substance (EC). The relationship with (including materials) is preferably as follows.

When an anodic EC material and an EC- or non-EC-cathodic redox substance are used, the redox substance possessed by the third electrode 3 is such that the oxidant is a cathodic redox substance. It is preferably more easily reduced than the oxidant. When a cathodic EC material and an EC or non-EC anodic redox substance are used, the redox substance possessed by the third electrode 3 is an anodic redox substance whose reduced product is an anodic redox substance. It is preferable that it is more easily oxidized than the reduced product of.

On the other hand, the cathodic redox substance and the redox substance possessed by the third electrode 3 are used, and the redox substance of the redox substance possessed by the third electrode 3 is more than the redox substance of the cathodic redox substance. Consider the case where it is easily oxidized. In this case, when an oxidant of the cathodic redox substance is generated in the EC element, electron transfer from the redox substance possessed by the third electrode 3 to the cathodic redox substance occurs, and the charge is charged. The balance will increase. Further, by using the anodic redox substance and the redox substance possessed by the third electrode 3, the redox substance of the third electrode 3 is reduced more than the redox substance of the anodic redox substance. Consider the easy case. In this case, when a reduced product of the anodic redox substance is generated in the EC element, electron transfer occurs from the anodic redox substance to the redox substance possessed by the third electrode 3, and the charge is transferred. The balance will increase.

The method for determining the ease of oxidation or reduction between the anodic redox substance / cathodic redox substance and the redox substance possessed by the third electrode 3 can be considered in the same manner as the above EC material. it can. In the case of a non-EC redox substance, even if there is no EC property in the target wavelength region, the absorption characteristics change in the wavelength region outside the target. Therefore, by measuring and evaluating the change in the absorption characteristics, it is possible to measure and evaluate not only the above (1-3c) but also the above (1-3a) or (1-3b) method. is there.

In the EC device of the present invention, the range in which the charge can be rebalanced is proportional to the amount of the redox substance contained in the third electrode 3. That is, as the amount of the redox substance increases, the range in which the charge can be rebalanced also increases. Therefore, it is preferable that the amount of the redox substance contained in the third electrode 3 is basically large within a range in which there is no problem in practical use of the device. A powerful method for increasing the amount of redox substance immobilized (contained) on the third electrode 3 is to increase the surface area of the electrode. In order to increase the surface area of the third electrode 3 with an element size suitable for the actual configuration, it is preferable that the third electrode 3 has a porous structure. Examples of the porous structure include those having a structure in which the effective area (roughness factor) with respect to the projected area is 10 times or more, preferably 100 times or more.

In the present invention, the constituent material of the third electrode 3 is not particularly limited. Materials having a porous structure include tin-doped indium oxide (ITO), zinc oxide, gallium-doped zinc oxide (GZO), aluminum-doped zinc oxide (AZO), tin oxide, and antimony-doped tin oxide (ATO), which are conductive oxides. ), Fluorine-doped zinc oxide (FTO), niobium-doped titanium oxide (TNO), titanium oxide, porous carbon material, porous metal, a film composed of a combination thereof, or the like can be used. When the third electrode 3 is arranged outside the optical path taken in by the EC element, a conductive electrode that scatters light other than the above-mentioned transparent conductive oxide, a non-transparent porous conductor, a carbon material, or platinum. , Metals such as titanium can also be used. The porous structure of the third electrode 3 preferably has a large effective area with a small projected area and has a nanometer-scale fine structure from the viewpoint of fabrication. There are no restrictions on the shape and manufacturing method of this porous structure, and nanostructures such as nanoparticle membranes, nanorods, nanowires, and nanotubes having communication holes can be used. Among them, a particle film having a large specific surface area per volume and easy to prepare is preferably used. As the size of the particles used when forming this particle film, those having an average particle size of 300 nm or less are desirable, and particles having an average particle size of 50 nm or less are preferably used.

In the present invention, the thickness of the third electrode 3 is preferably 100 nm or more, preferably 1 μm or more.

The arrangement of the three types of electrodes (1, 2, 3) described above will be described below. The EC element of the present invention has three types of electrodes (1, 2, 3), of which the first electrode 1 and the second electrode 2 are generally known as the electrode arrangement of the EC element. It is possible to use the arrangement method. As a typical example, there is an arrangement method in which the first electrode 1 and the second electrode 2 formed on the substrate (7, 8) face each other and a distance between electrodes of about 1 μm to 500 μm is provided. .. The arrangement of the third electrode 3 will be described later.

When introducing light into the EC element of the present invention, a specific method thereof can be freely selected depending on the application of the EC element, and a typical example will be described below. In the case of a transmissive EC element in which the first electrode 1 and the second electrode 2 face each other, the incident light passes through the first electrode 1 or the second electrode 2. Here, if the EC material contained in the EC element is in a colored state, at least a part of the light is absorbed by the EC material and is emitted through the other electrode. On the other hand, in the case of a reflection type EC element in which the first electrode 1 and the second electrode 2 face each other, the incident light passes through the first electrode 1 or the second electrode 2. Here, if the EC material contained in the EC element is in a colored state, at least a part of the light is absorbed by the EC material, folded back by a reflector, a scatterer, etc., and transmitted through an electrode transmitted at the time of incident and emitted. Will be done. The reflector, scatterer, etc. at this time are often arranged between the first electrode 1 and the second electrode 2, but are outside the electrode opposite to the electrode that transmits when light is incident. The arranged configuration can also be selected.

One of the major features of the EC element is that it has a higher maximum transmittance than the liquid crystal element of an absorption device that is widely used in general. In order to take advantage of this high transmittance, it is desirable that there is as little element as possible in the optical path until the light incident on the EC cell is emitted, other than the absorption of the EC material at the time of coloring. When the third electrode 3 constituting the EC element of the present invention is arranged in this optical path, the third electrode 3 may also be an element for reducing the transmittance of the EC element. Specifically, it is as described below. The third electrode 3 has a larger effective area than the first electrode 1 and the second electrode 2, and when it is attempted to realize this large effective area with a small projected area, the third electrode It is desirable that 3 has a porous structure. However, if the constituent material of the electrode having a porous structure is a material having a low (visible light) transmittance as a bulk such as metal or carbon, the transmittance may be significantly reduced by this electrode. Further, even when a material having a high transmittance as a bulk is used, if there is a difference in the refractive index with the electrolyte 4, the transmittance is reduced by scattering or the like. From these facts, in the present invention, it is more preferable that the third electrode 3 is arranged outside the optical path of light passing through at least one of the first electrode 1 and the second electrode 2. The term "outside the optical path" as used herein means that the light path is out of the optical path required for the application of using the EC element as the light absorption element from the above viewpoint. For example, when an EC element is used as a transmissive filter of an imaging device, it is used for necessary imaging in the entire region of a light receiving element (for example, CCD sensor, CMOS sensor) among all the light transmitted through the EC element. The optical path for the light that reaches the region is the optical path here. On the contrary, in the same case, even if the light passes through the EC element, the optical path for the light that reaches a region other than the region used for the necessary imaging of the light receiving element is included outside the optical path referred to here. In the present invention, by arranging the third electrode 3 outside the optical path, the constituent material of the third electrode 3 can be selected with a high degree of freedom as described above. Further, even when the redox substance contained in the third electrode 3 is EC-based, it can be used without any problem.

Next, the arrangement position of the third electrode 3 in the present invention will be described. When the colorant of the remaining EC material is reduced on the first electrode 1 and / or the second electrode 2 in order to suppress decolorization failure, it is desirable that the reaction can be performed uniformly on the same electrode. .. From this point of view, it is preferable that the third electrode 3 is arranged in at least a part of the periphery of the first electrode 1 and / or the second electrode 2, as shown in FIG. 3, for example. FIG. 3 is a top view showing an example of the EC element of the present invention. In FIG. 3, the first electrode 1 and the second electrode 2 appear to overlap each other. The third electrode 3 may be arranged so as to surround the four sides of the first electrode 1 and the second electrode 2 as shown in FIG. 3 (a), or the first electrode 3 may be arranged so as to surround the four sides as shown in FIG. 3 (b). It may be arranged so as to surround the three sides of the electrode 1 and the second electrode 2. Further, as shown in FIG. 3C, the first electrode 1 and the second electrode 2 may be arranged so as to surround both sides.

The third electrode 3 can be formed, for example, through the following steps.
(A) A part of the conductive substrate having the conductive film forming the first electrode 1 or the second electrode 2 is processed by etching or the like, and the conductive film is processed into the first electrode 1 or the second electrode 2. The process of dividing into multiple regions, including regions that are electrically independent of each other.
(B) A step of forming a third electrode 3 which is a porous electrode on a conductive film provided in the electrically independent region.
(C) A step of immobilizing a redox substance on the third electrode 3.

Any of the steps (A), (B) and (C) may be performed first. Further, the third electrode 3 may be formed on either the first electrode 1 or the substrate on which the second electrode 2 is arranged, but the substrate on which the first electrode 1 is arranged and the second electrode 3 are arranged. It may be formed on both of the substrates on which the second electrode 2 is arranged. However, when the third electrode 3 is formed, it should be electrically independent of the first electrode 1 and the second electrode 2.

(2) Partition 6
In the present invention, the third electrode 3 is an EC material remaining as a colored body on the first electrode 1 and / or the second electrode 2 when a decolorization failure occurs in the EC element 10. It can be said that it functions as a storage place for electric charges for an electrochemical decolorization reaction. Therefore, it is desirable that the EC material that is normally colored (during coloring or the like) does not reach the third electrode 3. It is not necessary to consider the case where the EC material is immobilized on the first electrode 1 or the second electrode 2, but the EC material can be freely diffused, such as being dissolved in the electrolyte 4. In this case, the arrival of the third electrode 3 may cause the colored body to be converted into a decolorized body. In order to suppress this, it is effective to reduce the substance transport between the first electrode 1 and / or the second electrode 2 to be colored and the third electrode 3. As a specific method, for example, a distance from the first electrode 1 and / or the second electrode 2 is taken, and between the first electrode 1, the second electrode 2, and the third electrode 3. Placement of structures that reduce material transport may be mentioned. In the former, for example, the distance between the first electrode 1 and / or the second electrode 2 and the third electrode 3 is larger than the distance between the first electrode 1 and the second electrode 2. To do. On the other hand, as the latter, as shown in FIG. 2, a method of forming a partition wall 6 having an opening 6a between the first electrode 1 and / or the second electrode 2 and the third electrode 3 is used. Can be mentioned. The partition wall 6 preferably has a porous wall itself. When the partition wall 6 is provided as shown in FIG. 2, it is necessary to have the opening 6a with the first electrode 1 and / or the second electrode 2 in order for the third electrode 3 to function effectively. This is because it is necessary to secure an electrical connection with the third electrode 3 via the electrolyte 4. Conversely, as long as the electrical connection between the first electrode 1 and / or the second electrode 2 and the third electrode 3 by the electrolyte 4 is secured to the extent necessary for effective charge balance, the first electrode It is preferable that the material transport between the 1 and / or the second electrode 2 and the third electrode 3 is reduced.

(3) Sealing material 5
The substrates (7, 8) constituting the EC element are preferably joined by the sealing material 5 in an arrangement in which the electrode surface of the first electrode 1 and the electrode surface of the second electrode 2 face each other. The sealing material 5 is stable and does not invade the electrolyte 4 in its characteristics after sealing, is electrochemically stable, does not cause an electrochemical reaction during the operation of the EC element, and permeates gas and liquid. It is preferable that the material is difficult to use and does not inhibit the redox reaction of the EC material. For example, an inorganic material such as glass frit, an organic material such as an epoxy resin or an acrylic resin, a metal or the like can be used. If the characteristics after sealing are unstable with respect to the electrolyte 4, there is a concern that the electrode may be contaminated with the eluted sealing material. Further, when the component of the sealing material 5 is electrochemically unstable, it may cause charge balance due to the electrode reaction. In addition, if gas and liquid (particularly oxygen and water) are easily permeated, care must be taken as they may cause charge balance due to their electrode reactions. The sealing material 5 may have a function of maintaining a distance between the first electrode 1 and the second electrode 2 by containing a spacer material or the like. If the sealing material 5 does not have a function of defining the distance between the first electrode 1 and the second electrode 2, a spacer may be separately arranged to maintain the distance between the two electrodes. The spacer chromatography material, silica beads, and inorganic materials as glass fibers or the like, polyimide, polytetrafluoroethylene, polydivinylbenzene, fluorine rubber, can be formed using an organic material such as epoxy resin. Note that more the spacer over, define the distance between the first electrode 1 constituting the EC element 10 and the second electrode 2, it is possible to hold.

(4) Electrolyte 4
The EC element of the present invention has an electrolyte 4 and an anodic organic EC material and / or a cathodic organic EC material between the first electrode 1 and the second electrode 2. In the present invention, the anodic organic EC material and the cathodic organic EC material may be dissolved in the electrolyte 4, or may be immobilized on the first electrode 1 or the second electrode 2. Good.

When the anodic organic EC material and the cathodic organic EC material are dissolved in the electrolyte, they are advantageous in the following two points as compared with the case of immobilization on the electrode.
(A) Since there is no limiting factor of the surface area of the electrode to be immobilized, the amount of EC material that can be present in the electrolyte is large.
(B) In the case of immobilization, it is often necessary to devise a structure and a manufacturing process for both the EC material to be immobilized and the electrode to be the immobilization carrier, but these are not provided.

Further, when the anodic organic EC material and the cathodic organic EC material are fixed to the electrodes, the EC materials are constrained to the electrodes, so that they are compared with the case where they are dissolved in the following points. It is advantageous.
(C) It is not necessary to prepare a structure such as a partition wall 6.
(D) The point that the response speed does not decrease due to the substance transport until the EC material reaches the electrode.

In the present invention, the electrolyte 4 includes the concepts of both the electrolyte itself and the electrolytic solution in which the electrolyte is dissolved in a solvent. As the electrolyte 4, for example, a salt compound dissolved in a solvent, an ionic liquid in which the salt compound itself also serves as a solvent, or the like can be used.

The solvent constituting the electrolyte is selected according to the application in consideration of the solubility of solutes such as EC molecules, vapor pressure, viscosity, potential window, etc., but a solvent having polarity is preferable. No. Specifically, methanol, ethanol, propylene carbonate, ethylene carbonate, dimethyl sulfoxide, dimethoxyethane, γ-butyrolactone, γ-valerolactone, sulfolane, dimethylformamide, dimethoxyethane, tetrahydrofuran, acetonitrile, propionnitrile, benzonitrile, dimethylacetamide. , Methylpyrrolidinone, organic polar solvents such as dioxolane, water, and mixtures thereof. Of these, cyclic ester compounds and nitrile compounds are preferably used, and among them, propylene carbonate is most preferably used.

Further, the solvent may contain a polymer or a gelling agent to form a highly viscous solvent or a gel. Such polymers are not particularly limited, but are, for example, polyacrylonitrile, carboxymethyl cellulose, polyvinyl chloride, polyethylene oxide, polypropylene oxide, polyurethane, polyacrylate, polymethacrylate, polyamide, polyacrylamide, polyester, naphthion (). Trade name), saccharide compounds and the like can be mentioned. It is preferable to impart a functional group to the polymer or gelling agent in order to improve its properties. Specific examples of the functional group include a cyano group, a hydroxyl group, an ester, an ether, an amide, an amino group, a carboxylic acid group, and a sulfonic acid group.

The salt compound used for this electrolyte is an ion-dissociable salt, has good solubility in a solvent, and has high compatibility with a solid electrolyte, and is a stable substance at the operating potential of an electrochromic element. If there is, there is no particular limitation. A suitable combination of various cations and anions can be used. Examples of cations include metal ions such as alkali metal ions and alkaline earth metal ions, and organic ions such as quaternary ammonium ions. Specific examples thereof include ions such as Li, Na, K, Ca, Ba, tetramethylammonium, tetraethylammonium, and tetrabutylammonium. Examples of anions include anions of various fluorine compounds, halide ions and the like. ClO ₄ specifically ^{_{-, SCN -, BF 4 -}} , AsF 6 -, CF 3 SO 3 -, CF 3 SO 2 NSO 2 CF 3 -, PF 6 -, I -, Br -, Cl - , etc. can be mentioned Be done. Further, by using the EC material which is also a salt compound, it is possible to combine the solution of the EC material and the solution of the electrolyte. Examples of EC materials that are also salt compounds include viologen derivative salts and the like.

When introducing the electrolyte 4 into the EC element when manufacturing the EC element of the present invention, for example, while forming an opening in a part of the facing electrodes (1, 2) or the sealing material 5. There is a method of injecting the electrolyte 4 into a cell formed by joining the substrates (7, 8). This method can be applied even when the EC material described later is dissolved in the electrolyte 4. Specific methods for introducing the electrolyte 4 into the cell include a vacuum injection method, an atmospheric injection method, a meniscus method, and the like. By the way, after injecting the electrolyte 4 or the like into the cell, the opening is sealed. Further, a drop-bonding method having no injection port is also preferably used.

(5) EC material The EC material used in the EC element of the present invention is an organic compound. This organic compound includes both a low molecular weight organic compound and a high molecular weight organic compound, and all of the materials are of a type that are colored by applying an electrical stimulus from the outside. Examples of this type of polymer organic compound include polymer compounds containing a pyridinium salt, and specific examples thereof include viologen-based polymer compounds. In the present invention, the EC material is preferably a low molecular weight organic compound having a molecular weight of 2000 or less, and is a compound that changes from a decolorized body to a colored body by an oxidation reaction or a reduction reaction at an electrode. In the EC device of the present invention, either an anodic EC material or a cathodic EC material is always used.

Here, the anodic EC material is a material that is colored by an oxidation reaction in which electrons are removed from the material. On the other hand, the cathodic EC material, on the contrary, is a material that is colored by a reduction reaction in which electrons are given to the material.

As anodic EC materials, for example, thiophene derivatives, amines having an aromatic ring (for example, phenazine derivatives, triallylamine derivatives), pyrrole derivatives, thiadin derivatives, triallylmethane derivatives, bisphenylmethane derivatives, xanthene derivatives, fluorane derivatives , Spiropyran derivatives. Among these, as the anode electrochromic molecule, low molecular weight thiophene derivatives (for example, monothiophene derivatives, oligothiophene derivatives, thienoacene derivatives) and amines having a low molecular weight aromatic ring (for example, phenazine derivatives and triallylamine derivatives) It is preferable to have.

This is because by using these molecules in the electrochromic layer, it is easy to provide an electrochromic device having a desired absorption wavelength profile. These molecules have an absorption peak in the ultraviolet region in the neutral state, have no absorption in the visible light region, and take a decolorized state with high transmittance in the visible light region. Then, these molecules become radical cations due to the oxidation reaction, and the absorption shifts to the visible light region, resulting in a colored state. By expanding or contracting the π-conjugated length of these molecules and changing the substituents to change the π-conjugated system, the absorption wavelength and the potential at which the redox reaction proceeds can be designed.

Here, the small molecule has a molecular weight of 2000 or less, preferably 1000 or less. Examples of the cathodic electrochromic molecule include pyridine compounds such as viologen derivatives and quinone compounds. By expanding or contracting the π-conjugated length of these molecules and changing the substituents to change the π-conjugated system, the absorption wavelength and the potential at which the redox reaction proceeds can be designed.

In the present invention, the EC material may include a plurality of types of anodic EC material and cathodic EC material, respectively.

Further, the EC material may be used in a form of being immobilized on the first electrode 1 and / or the second electrode 2. This is because, in the EC element of the present invention, when adjusting the charge imbalance, it is sufficient that the charge is transferred between the electrodes, and the EC material diffuses through the electrolyte 4 and reaches the third electrode 3. This is because there is no need to let them. However, it may be diffused to reach the third electrode only if it is not necessary. Further, as described above, when the EC material is freely diffusible through the electrolyte 4, there is a possibility that the colored body is converted into a decolorized body by reaching the third electrode 3. In order to suppress this, a device for reducing the transport of substances such as the partition wall 6 may be used. On the other hand, when the EC material is immobilized on the first electrode 1 and / or the second electrode 2, it is preferable in that there is almost no possibility that the colored body is converted into a decolorized body. ..

Specific methods for immobilizing the EC material include a method of binding the EC material to the electrode material via a functional group contained in the EC material molecule, and a comprehensive method of bonding the EC material using a force such as electrostatic interaction (for example,). , Membrane state), EC material may be physically adsorbed on the electrode, etc. Among them, from the viewpoint of realizing a quick response of the EC element, a method in which a low molecular weight organic compound as an EC material is chemically bonded to a porous electrode through a functional group and a method in which a polymer compound as an EC material is formed on the electrode are preferable. .. As a specific example of the former, a small molecule which is an EC material is passed through a functional group such as an acid group (for example, a phosphoric acid group or a carboxylic acid group) on an oxide fine particle electrode such as titanium oxide, zinc oxide or tin oxide. Examples thereof include a method of immobilizing an organic compound. An example of the latter is a method of polymerizing a viologen polymer on a transparent electrode. As a method for forming a polymerization on a transparent electrode of a viologen polymer, electrolytic polymerization can be mentioned.

The method for immobilizing the EC material described above can be adopted when immobilizing the redox substance contained in the third electrode 3.

8. EC element driving method The EC element of the present invention adjusts the charge balance of the EC element by using the third electrode 3. In the EC element of the present invention, since the third electrode 3 has a redox substance and the ease of oxidation or reduction is defined with the EC material, the ease of oxidation or reduction is defined. It can be used to rebalance the charge.

Hereinafter, specific examples of the method for driving the EC element of the present invention will be described. In order to decolorize the EC element, for example, in a state where the first electrode 1 and the second electrode 2 are short-circuited, the anodic EC material contained in the EC element 10 remains colored as an oxide. Think about the state. That is, consider the case where an anodic charge imbalance occurs. At this time, if the anodic EC material of the oxidant and the redox of the redox substance possessed by the third electrode 3 can transfer and receive electric charges directly or through an electrode reaction, the charge is as follows. Due to the ease of oxidation and reduction, electrons are supplied from the redox of the redox substance of the third electrode 3 to the anodic EC material of the oxidant, so that the anodic charge imbalance is eliminated. To. On the contrary, consider a state in which the cathodic EC material contained in the EC element 10 remains colored as a reducing body. That is, consider the case where the cathodic charge is imbalanced. At this time, if the cathodic EC material of the reducing body and the oxidizing body of the redox substance possessed by the third electrode 3 can transfer and receive charges directly or through an electrode reaction, the charge is as follows. Due to the ease of oxidation / reduction, electrons are supplied from the cathodic EC material of the reducing body to the redox substance possessed by the third electrode 3, so that the imbalance of the cathodic charge is eliminated. For the same reason, even in the case of an EC element containing both an anodic EC material and a cathodic EC material, the charge imbalance is effectively eliminated by using the redox substance possessed by the third electrode 3. be able to.

As described above, since the EC element of the present invention can rebalance the electric charge depending on the ease of oxidation or reduction, the effect can be exhibited without providing a mechanism for detecting the electric charge balance. Can be done.

By the way, the electric charge transfer between the EC material and the redox substance possessed by the third electrode 3 may be a direct charge transfer between the material and the substance, but by using the transfer through the electrode, the electric charge can be transferred. The effect can be increased. The reason will be explained below. In order for the transfer of electric charge between the material and the substance to proceed directly, it is necessary to make the distance between the material and the substance sufficiently close. This is almost impossible when the EC material is fixed to the first electrode 1 and / or the second electrode 2, and the process of transporting the substance even when it is dissolved in the electrolyte 4. It takes a relatively long time because it needs to go through. On the other hand, for example, when the third electrode 3 is short-circuited with the first electrode 1 (the same applies hereinafter to the second electrode 2), the potentials of the third electrode 3 and the first electrode 1 are the same. Therefore, even in the first electrode 1, the transfer of electric charge between the EC material and the redox substance possessed by the third electrode 3 can proceed. In this way, the transfer of electric charge between the third electrode 3, the EC material using the first electrode 1 or the second electrode 2, and the redox substance possessed by the third electrode 3 is transferred through the electrode reaction. It is called the transfer of electric charge. In normal operation, the EC material undergoes a coloring / decoloring reaction at the first electrode 1 or the second electrode 2, so that the colored body of the EC material is the first electrode 1 or the second electrode 2. Often present in the vicinity. When the EC material is fixed to the first electrode 1 and / or the second electrode 2, it is always present in the vicinity of the corresponding electrode. Therefore, by more effectively utilizing the transfer through the electrodes, it is effective even when the EC material is fixed to the first electrode 1 and / or the second electrode 2 in a relatively short time. The charge can be rebalanced.

When the transfer of electric charge through the electrode reaction described above is used, it is necessary to appropriately control the potential difference between the third electrode 3 and the first electrode 1 and / or the second electrode 2. A specific example will be given below. When the charge is not rebalanced, the circuit is usually open between the third electrode 3 and the first electrode 1 and between the third electrode 3 and the second electrode 2. There is. This is to prevent unnecessary charge rebalancing from progressing due to charge transfer through the electrode reaction when there is no intention of performing charge rebalancing. Then, for example, when rebalancing the electric charge at the time of decoloring, the third electrode 3 and the first electrode 1 and / or the third electrode 3 and the second electrode 2 are connected. , The potential difference (voltage) between the target electrodes is appropriately controlled. In the present invention, the timing of rebalancing the electric charge is not particularly limited, but the EC material in the colored state remaining after a sufficient time has passed for the EC element to perform the decoloring operation is basically an imbalance of the electric charge. It is caused by. Therefore, a typical example is a decoloring operation in which the remaining colored EC material is decolorized by rebalancing. Further, if the absolute value of the potential difference controlled at this time is too large, it may cause a deterioration reaction of the EC material and the electrolyte. Therefore, the value is set in a range that does not adversely affect the components of the element in use. For example, the potential difference V can be in the range of about 0V ≦ V ≦ 5V. It should be noted that applying a large voltage (absolute value) when performing charge rebalancing is advantageous in that it promotes the electrode reaction required for charge rebalancing. On the other hand, applying a small voltage (absolute value) when rebalancing the electric charge is advantageous in that it can suppress an adverse effect on the EC element and an increase in power consumption of the EC element. It is preferable that the range of the voltage (absolute value) applied when rebalancing the electric charge is appropriately set according to the characteristics of the device and the usage environment. The voltage applied when rebalancing the electric charge is typically 0V (short-circuited state), but the voltage is smaller than that of the coloring operation for the purpose of retaining the electric charge and accelerating the rebalancing of the electric charge. For example, 1 V or less) may be appropriately applied between the first electrode 1, the second electrode 2, and the third electrode.

When applying a voltage, the time for applying the voltage varies greatly depending on the value of the applied voltage, but the basic idea is that it is more than the time when the electric double layer is formed on the surface of the electrode and the Faraday current starts to flow. It is preferable that the time is long and the time until the charge balance reaches the normal point. Specifically, it is 1 ms or more. When the voltage is not positively applied from the outside, there is no particular upper limit to the time for applying the voltage, and it is preferable to always short-circuit the voltage during the suspension period to rebalance the charge. When voltage is positively applied from the outside to rebalance the charge, the time is longer than the time when the electric double layer is formed on the electrode surface and the Faraday current starts to flow, and the charge balance exceeds the normal point. It is preferable that the time is shorter than the period during which the residual color of the colored body of the EC material having the opposite polarity is generated. Specifically, it largely depends on the response speed of the EC element, but as an example, it can be 1 ms or more and 10 s or less. It is also preferable to apply a voltage for a short time and select the next application time and application voltage based on the result. Further, as the application pattern of these voltages, in addition to continuous application, application may be performed with a certain pattern such as a pulse shape.

When the voltage is positively applied, it is preferable to determine the polarity and magnitude of the applied voltage after detecting the charge balance state of the EC element. Specifically, it has a step of controlling the potential difference between at least one of the first electrode 1 and the second electrode 2 and the third electrode 3 based on the detected charge balance state of the EC element. Is preferable. Further, it is preferable to determine the execution of the additional potential difference control based on the detected charge balance state of the EC element after the potential difference is controlled based on the step of controlling the potential difference. The detection of the charge balance state and the application of the voltage will be described below.

The EC device of the present invention detects the charge balance state as necessary, and controls the voltage between the third electrode 3 and the first electrode 1 and / or the second electrode 2 based on the information. You may. For example, when both the anodic EC material and the cathodic EC material are used, the anodic EC material may remain colored or the cathodic EC material may remain colored. In order to effectively decolorize the remaining colored EC material, it is necessary to apply a voltage corresponding to the polarity of the charge balance to the third electrode 3 and the first electrode 1 and / or the second electrode 2. There is. If a voltage of opposite polarity is applied at this time, the charge imbalance expands, the amount of colored material remaining in the color increases, and the decolorization failure worsens, so it is important to detect the polarity of the charge balance. is there. Further, even if the polarities are suitable, if an amount of charge exceeding the degree of charge imbalance is applied, charge imbalance of opposite polarity may occur. Therefore, it is important to control the voltage and charge amount based on the detected charge balance state.

As a means for detecting the charge balance of the EC element, for example, there are a method using light absorption of an EC material, a method using electrode potential measurement, and the like. When using the light absorption of an EC material, as a specific method, by comparing the amount of light absorbed at the absorption wavelength characteristic of each of the anodic material and the cathodic material contained in the EC element. It can be carried out. More specifically, the following examples can be given. For example, it can be performed by preparing a light source having an absorption wavelength characteristic of each of the anode material and the cathode material, incidenting the light source on the EC element, and detecting the emitted light with the light receiving element. Then, the amount of change in the absorbance at each absorption wavelength from the initial decolorized state is obtained, and when there is a difference in the amount of change, the charge balance is such that the EC material having the larger amount of change is proportional to the amount of change in absorbance. It can be judged that the color remains with. The light source and detector used for this detection can be used without limitation as long as they have the light intensity and sensitivity required for detection and do not adversely affect the characteristics of the EC element as an application. it can. Examples of the light source include LEDs and the like. Examples of the light receiving element include a photodiode and the like. The light source, the detector, the circuit based on the signal from the detector, the circuit for selecting the subsequent process from the setting conditions, and the like may be attached to the EC device including the EC element. By attaching it to the EC device, it is possible to realize an operation that surely reflects the characteristics peculiar to the EC element even when the EC device is replaced. On the other hand, if necessary, it may be provided to a member other than the EC device. For example, if the EC device is used for a window, it may be attached to a window frame or the like. If it is used for a camera, it may be attached to the camera body or the like. This is preferable in that the volume limitation is relaxed and the common availability of the circuit is improved. Further, as for the detection method, a method such as a user visually determining and inputting information (for example, pressing a button) can be selected for reasons such as a limitation on the number of parts.

When electrode potential measurement is used as a method for detecting the charge balance of an EC element, as a specific method, the potential of the first electrode 1 and / or the second electrode 2 is measured using a reference electrode or the like. To do. A specific example will be described below. Since the following description also applies to the case where the coloring of the cathodic EC material remains if the polarities are opposite, the color remaining of the anodic EC material will be described as a representative of both cases. Here, when the operation of maximizing the transmittance of the EC element, for example, when the first electrode 1 and the second electrode 2 are short-circuited, the anodic EC material remains colored due to the charge imbalance. That is, consider the case where a part of the anodic EC material remains as an oxide. At this time, since the cathodic EC material in the EC element is in a substantially reduced state (decolorized state), the potential of the first electrode 1 and / or the second electrode 2 is that of the anodic EC material. It is considered to be defined by the ratio of the oxidant to the reductant. Materials used as EC materials generally exhibit highly reversible redox properties. This is because, on the contrary, if it is not shown, its responsiveness and durability will decrease, and its power consumption will increase. Therefore, the potential of the first electrode 1 and / or the second electrode 2 follows the Nernst equation from the standard electrode potential of the anodic EC material, and the concentration ratio of the oxidized body to the reduced body (to be exact, active). The value is slightly deviated in proportion to the natural logarithmic value of (quantity ratio). By utilizing this, the state of charge balance can be detected. For example, when the anodic EC material and the cathodic EC material are dissolved in the electrolyte and can move freely, the potential of the first electrode 1 and / or the second electrode 2 is the anodic EC material or It can be determined by which oxidation-reduction potential of the cathodic EC material is close to. For example, if the electrode potential is close to the oxidation-reduction potential of the cathodic EC material, it can be determined that the charge balance is in the direction in which the cathodic EC material remains in color, and the magnitude of the difference is the degree of charge imbalance. To reflect. Further, when the anodic EC material and the cathodic EC material are immobilized on each of the first electrode 1 and the second electrode 2, the potentials of the electrodes on which the EC material is immobilized correspond to each other. The direction and degree of deviation from the redox potential of the immobilized material are measured. From this deviation, the polarity and degree of charge imbalance can be determined. An example is described below. It is assumed that the potential of the electrode on which the cathodic EC material is immobilized is at a potential at which the cathodic EC material is considered to be substantially an oxidant (sufficiently positive compared to the redox potential). At the same time, it is assumed that the potential of the electrode on which the anodic EC material is immobilized is close to the redox potential to the extent that the oxidant and the reducer of the anodic EC material coexist. In this case, the charge balance can be determined to be the degree of charge imbalance in the direction in which the anodic EC material remains in color. Similar to the above-mentioned light detection, a circuit or the like that performs these detections, selection of a process following from the setting conditions, and the like may be attached to the EC device or may be provided to a member other than the EC device.

FIG. 4 is a schematic view showing an example of the control circuit of the EC element of the present invention. The control circuit of FIG. 4 has a variable voltage source 24 and switches 25, 26, 27 provided between the variable voltage source 24 and the electrodes (1, 2, 3). During normal driving, switches 25 and 27 are turned on and switches 26 are turned off, and a voltage is applied between the first electrode 1 and the second electrode 2. On the other hand, when rebalancing the charge, one of the following is selected.
(A) The switches 25 and 26 are turned on and the switches 27 are turned off, and a voltage is applied between the first electrode 1 and the third electrode 3.
(B) With the switches 26 and 27 turned on and the switch 25 turned off, a voltage is applied between the second electrode 2 and the third electrode 3.
(C) With the switches 25, 26, and 27 all turned on, a voltage is applied between the first electrode 1, the second electrode, and the third electrode 3.

9. Effect In the present invention, by using the third electrode 3, it is possible to eliminate the decolorization defect due to the charge imbalance of the EC element. As a typical example, the transmittance can be improved by converting the colored body of the EC material that remains even when the operation of maximizing the transmittance of the EC element is performed into a decolorizing body. As a countermeasure against decolorization failure due to this charge imbalance, for example, there is a method using a redox buffer shown in Patent Document 1.

However, as explained in "Problems to be Solved by the Invention", the method using the redox buffer cannot eliminate the charge imbalance between the display electrodes. Therefore, it is not possible to modify the ratio of the contribution of the colorant of the anodic EC material to the contribution of the colorant of the cathode EC material in the spectrum of the EC element at the time of coloring.

On the other hand, the method of the present invention, that is, the method using the third electrode 3, uses the third electrode 3 having a redox substance for charge adjustment to balance the broken charges between the display electrodes. It is to rebalance. In other words, the charge balance of the EC element as a whole does not change, but the charge imbalance between the display electrodes is taken over by the third electrode 3 having the redox substance. In this case, when coloring the EC material, only the first electrode 1 and the second electrode 2 are driven without using the third electrode 3, so that the contribution of the anode material to the spectrum at the time of coloring due to the charge imbalance. The state in which the ratio of the minute to the contribution of the cathode material is changed cannot be reproduced. Therefore, by using the method of the present invention, it is possible to correct the spectrum of the above-mentioned EC element at the time of coloring.

Hereinafter, description will be made with reference to the drawings. FIG. 5A is a diagram showing an absorption spectrum of an EC element that does not correspond to the present invention, and FIG. 5B is a diagram showing an absorption spectrum of an EC element of the present invention. 5 (a) and 5 (b) show a calculation example of the absorption spectrum (vertical axis: absorbance, horizontal axis: wavelength) of the EC element when the anodic EC material and the cathodic EC material are used. ing. Here, the anodic EC material has a characteristic absorption peak at 455 nm and 500 nm, and the cathodic EC material has a characteristic absorption peak at 605 nm. When the charge balance of the EC element is normal, the absorption spectrum of the EC element is represented by the spectrum a in FIG. 5A. Here, the absorption spectrum when the charge balance of the EC element changes in the direction in which the colored body of the cathodic EC material remains is represented by the spectra b in FIGS. 5A and 5B. The absorption spectrum of the EC element at the time of coloring at this time is the spectrum c in FIGS. 5 (a) and 5 (b), and the absorption of the anodic EC material (455 nm, from the spectrum a in the state where the charge balance is normal). 500 nm) will be reduced. This change in spectrum due to the change in charge balance cannot be eliminated by using a redox buffer.

However, in the method of the present invention, since the collapsed charge balance can be rebalanced, it is possible to maintain a spectrum in which the charge balance is normal as shown in the spectrum d in FIG. 5 (b). Since the spectrum d in FIG. 5B is in good agreement with the spectrum a in FIG. 5A, it can be seen in FIG. 5 that the EC element of the present invention maintains the spectrum in a normal state. It is shown.

Therefore, the method of the present invention (a method using a third electrode having a redox substance) can solve the problem when a redox buffer is used as in Patent Document 1. That is, it is possible to solve an increase in power consumption, a decrease in response speed, and a change in the ratio of a colored body of an anodic EC material to a colored body of a cathodic EC material in a normal coloring operation of an EC element.

10. Applications The EC element of the present invention can be used as a constituent member of an optical filter, a lens unit, an image pickup device, a window material, or the like.

(Optical filter)
The optical filter of the present invention has an EC element of the present invention and an active element electrically connected to the EC element. Specific examples of the active element electrically connected to the EC element include a transistor for controlling the transmittance of the EC element. Examples of the transistor include a TFT and a MIM element. Here, the TFT is also called a thin film transistor, and a semiconductor or an oxide semiconductor is used as a constituent material thereof.

(Lens unit)
The lens unit of the present invention includes an imaging optical system having a plurality of lenses and an optical filter having the EC element of the present invention. The optical filter constituting the lens unit may be provided between a plurality of lenses and the lens, or may be provided outside the lens. In the lens unit of the present invention, the amount of light passing through the imaging optical system or the amount of light passing through can be adjusted by an optical filter.

(Imaging device)
The image pickup device of the present invention includes an optical filter and an image pickup element that receives light that has passed through the optical filter. The image pickup device constituting the image pickup device is an element that receives light transmitted through an optical filter and is also called a light receiving element.

Specific examples of the imaging device include a camera, a video camera, a camera-equipped mobile phone, and the like. The image pickup apparatus may have a form in which the image pickup optical system is removable, that is, the main body having the image pickup element and the lens unit having the lens can be separated.

Here, when the image pickup apparatus can be separated into the main body and the lens unit, the present invention also includes a form in which an optical filter separate from the image pickup apparatus is used at the time of imaging. In such a case, the arrangement position of the optical filter includes the outside of the lens unit, between the lens unit and the light receiving element, between a plurality of lenses (when the lens unit has a plurality of lenses), and the like.

When the EC element of the present invention is used as a constituent member of the image pickup apparatus, the arrangement position of the EC element is not particularly limited. For example, it may be in front of the image pickup optical system or just before the image pickup element. For example, by providing the EC element of the present invention in the optical path of the image pickup optical system connected to the image pickup element, the amount of light received by the image pickup element or the wavelength distribution characteristic of the incident light can be controlled. Further, this imaging optical system can also be called a lens system. Examples of the imaging optical system include a lens unit having a plurality of lenses.

Further, when the EC element of the present invention is used in an image pickup apparatus, since the EC element can exhibit high transparency in the decolorized state, a sufficient amount of transmitted light can be obtained with respect to the incident light, and the incident light can be emitted in the colored state. Optical characteristics that are reliably shaded and modulated can be obtained.

When the image pickup device to which the lens unit can be attached and detached has an optical filter, it may be provided so as to be arranged between the lens unit and the image pickup element when the lens unit is attached.

When the imaging device has an imaging optical system, the optical filter may be arranged between the lenses or between the lenses and the imaging element, and the imaging optics may be arranged between the optical filter and the imaging element. The optical filter may be arranged so that the system is arranged.

When the EC element of the present invention is used in an image pickup device such as a camera, the amount of light can be reduced without lowering the gain of the image pickup device.

FIG. 6 is a schematic view showing an example of an embodiment in the image pickup apparatus of the present invention. The image pickup device 100 of FIG. 6 includes a lens unit 102 and an image pickup unit 103, and the lens unit 102 is detachably connected to the image pickup unit 103 via a mount member (not shown). Further, the optical filter 101 is arranged in the image pickup unit 103, specifically, in the lens unit 102.

In FIG. 6, the lens unit 102 is a unit having a plurality of lenses or lens groups, and is a rear focus type zoom lens that focuses on the image sensor 110 side from the aperture.

In FIG. 6, the lens unit 102 has a first lens group 104 having a positive refractive power, a second lens group 105 having a negative refractive power, and a third lens group 106 having a positive refractive power in order from the object side. It has four lens groups of the fourth lens group 107 of the refractive power of. In FIG. 6, an aperture diaphragm 108 is provided between the second lens group 105 and the third lens group 106. The image pickup apparatus 100 of FIG. 6 changes the distance between the second lens group 105 and the lens group 106 of the third group to perform magnification change, and moves a part of the lens groups of the fourth lens group 107. Focus. In FIG. 6, the lens unit 102 has an aperture diaphragm 108 between the second lens group 105 and the third lens group 106. Each member is arranged so that the light passing through the lens unit 102 passes through each lens group ( 104 to 107), the aperture diaphragm 108, and the optical filter 101 and is received by the image sensor 110. The amount of light received by the image sensor 110 can be adjusted by using the aperture diaphragm 108 and the optical filter 101. In FIG. 6, the image pickup unit 103 has a glass block 109 and an image pickup element 110. An optical filter 101 is arranged between the glass block 109 and the image sensor 110.

Specifically, the glass block 109 is a glass block such as a low-pass filter, a face plate, or a color filter.

The image sensor 110 is a sensor unit that receives light that has passed through the lens unit 102, and an image sensor such as a CCD or CMOS can be used. Further, an optical sensor such as a photodiode may be used, and a sensor that acquires and outputs information on the intensity or wavelength of light can be appropriately used.

In FIG. 6, in the image pickup unit 103, an optical filter 101 is arranged between the glass block 109 in the image pickup unit 103 and the image pickup element 110. In the image pickup apparatus of the present invention, the arrangement position of the optical filter 101 is not particularly limited, and may be, for example, arranged between the third lens group 106 and the fourth lens group 107, or the lens unit. It may be arranged outside the 102.

By arranging the optical filter 101 at a position where the light converges, there is an advantage that the area of the optical filter 101 can be reduced. Further, in the image pickup apparatus of the present invention, the form of the lens unit 102 can be appropriately selected, and in addition to the rear focus type, an inner focus type in which focusing is performed before the aperture may be used, or another type may be used. In addition to the zoom lens, a special lens such as a fisheye lens or a macro lens can be appropriately selected.

Examples of such an image pickup device include products having a combination of light amount adjustment and an image pickup element, and are, for example, image pickup parts such as cameras, digital cameras, video cameras, digital video cameras, mobile phones, smartphones, PCs, and tablets. You may.

(Window material)
The window material of the present invention has a pair of transparent substrates, an EC element provided between the transparent substrates, and an active element for controlling the transmittance of the EC element. This active element is connected to the EC element, but the connection form to the EC element may be a directly connected form or an indirectly connected form. In the window material of the present invention, the amount of light transmitted through the transparent substrate can be adjusted by the EC element. Further, by adding a member such as a window frame to this window material, it can be used as a window. The window material of the present invention can be used for windows of aircraft, automobiles, houses and the like. Further, the window material having an EC element can also be called a window material having an electronic curtain.

7A and 7B are schematic views showing an example of an embodiment of the window material of the present invention, FIG. 7A is a perspective view, and FIG. 7B is a cross-sectional view taken along the line XX'of FIG. 7A. is there.

The window material 111 of FIG. 7 is a dimming window, and is integrated with the EC element 114 (however, the third electrode 3 is not shown) and the transparent plate 113 sandwiching the EC element 114 by surrounding the whole. It consists of a frame 112. The driving means of the window material 111 of FIG. 7 may be integrated in the frame 112, or may be connected to the EC element 114 through wiring arranged outside the frame 112.

In the window material 111 of FIG. 7, the transparent plate 113 is not particularly limited as long as it is a material having a high light transmittance, and is preferably a glass material in consideration of its use as a window. In FIG. 7, the EC element 114 is a constituent member independent of the transparent plate 113, but for example, the substrate (7, 8) constituting the EC element 114 may be regarded as the transparent plate 113.

In the window material 111 of FIG. 7, the material of the frame 112 is not particularly limited, but a frame 112 may be regarded as a whole having a form in which at least a part of the EC element 114 is covered and integrated.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[Synthesis Example 1] Synthesis of Compound 1 Compound 1, which is an anodic EC material, was synthesized according to the synthesis scheme shown below.

The reagents and solvents shown below were placed in a 50 ml reaction vessel.
XX-1 (2,5-dibromoethylenedioxythiophene): 500 mg (1.67 mmol)
2-Isopropoxy-6-methoxyphenylboronic acid: 1.05 g (5.0 mmol)
Toluene: 10 ml
Tetrahydrofuran: 5 ml)

Next, nitrogen was used to remove oxygen (dissolved oxygen) present in the solution.

Next, the reagents shown below were added under a nitrogen atmosphere.
Pd (OAc) ₂ : 19 mg (0.083 mmol)
2-Dicyclohexylphosphino-2', 6'-dimethoxybiphenyl (S-Phos): 89 mg (0.22 mmol)
Tripotassium Phosphate: 1.92 g (8.35 mmol)

Next, the reaction was carried out for 7 hours while heating and refluxing the reaction solution at 110 ° C.

Next, the reaction solution was cooled to room temperature and then concentrated under reduced pressure to obtain a crude product. Next, the obtained crude product was separated and purified using silica gel chromatography (mobile phase: hexane / ethyl acetate = 4/3) to obtain 420 mg (yield 54%) of compound 1 as a white solid powder. Obtained.

By MALDI-MS measurement, 470, which is M ⁺ of the obtained compound, was confirmed. The measurement results of the NMR spectrum of the obtained compound are shown below.
^{1 1} H-NMR (CDCl ₃ ) σ (ppm): 7.21 (t, 2H), 6.63 (d, 2H), 6.60 (d, 2H), 4.41 (m, 2H), 4 .20 (s, 4H), 3.81 (s, 6H), 1.25 (s, 6H), 1.24 (s, 6H).

[Synthesis Example 2] Synthesis of Compound 2 Compound 2, which is a cathodic EC material, was synthesized based on the literature of Cinnseaarch et al. (Solar Energy Materials and Solar Cells Vol. 57 (1999), pp. 107-125).

[Synthesis Example 3] Synthesis of Compound 3 Compound 3, which is a cathodic redox substance, was synthesized based on the literature of Cinnseaarch et al. (Solar Energy Materials and Solar Cells Vol. 57 (1999), pp. 107-125). Compound 3 is a compound having EC properties.

[Synthesis Example 4] Synthesis of Compound 4 The following compound 4, which is an anodic EC material, was synthesized based on the literature of Cummins et al. (Journal of Physical Chemistry B Vol. 104 (2000), 11449-11459).

[Example 1]
(Manufacturing of element)
The EC element 30a shown in FIG. 8 was manufactured by the following steps.

(1) Preparation of Transparent Conductive Glass First, two transparent conductive glasses (TEC15, manufactured by Nippon Sheet Glass) on which a fluorine-doped tin oxide (FTO) film was formed were prepared.

(2) Preparation of Substrate Next, using a diamond tool, a part of the FTO film contained in the transparent conductive glass was removed, and the FTO film was divided into three parts. Specifically, the FTO film 42 provided in the central region serving as the first electrode 31 or the second electrode 32 and the first electrode 31 or the second electrode 32 are electrically independent. It was divided into FTO films 33a provided in the regions at both ends, which are the regions where the three electrodes are formed.

(3) Preparation of third electrode Mix 12 g of antimony-doped tin oxide nanoparticles (manufactured by Ishihara Sangyo Co., Ltd.), 2 mL of concentrated nitric acid, and 200 mL of water, stir at 80 ° C. for 8 hours, and vacuum dry for 1 day. So, I got a cake of tin oxide nanoparticles. Next, 20 mL of water, 1.2 g of polyethylene glycol, and 0.4 g of hydroxypropyl cellulose were added to 4 g of this cake, and the mixture was stirred for 15 days to prepare a slurry. Next, this slurry is applied and formed on the FTO film 33a provided in the formation region of the third electrode 33, and then fired at 500 ° C. for 30 minutes to obtain an antimony-doped tin oxide nanoparticle film (hereinafter referred to as “)”. , Sometimes referred to as "nanoparticle film"). At this time, the specific surface area of the formed nanoparticle film was 450 cm ² / cm ² .

Next, an ethanol solution of 5 mM 1,1'-ferrocene dicarboxylic acid (Fc (COOH) ₂ ) was applied to the nanoparticle film, allowed to stand overnight, and then the nanoparticle film was washed with ethanol and dried. It was. As a result, 1,1'-ferrocene dicarboxylic acid (Fc (COOH) ₂ ) was immobilized on the nanoparticle film. Next, nitrosyl tetrafluoroborate was used to oxidize an amount corresponding to half of the ferrocene dicarboxylic acid immobilized on the nanoparticle film. As a result, the ratio of the redox substance (ferrocenedicarboxylic acid) immobilized on the nanoparticle film to the reduced substance was set to about 1: 1. As described above, a third electrode 33 in which a non-EC redox substance (ferrocene dicarboxylic acid) was immobilized on the nanoparticle film was prepared.

(4) Adhesion of Substrate A UV curable adhesive (TB3035B, manufactured by ThreeBond Co., Ltd.), which is a mixture of 100 μm spacer beads as a sealing material 35, is applied to two transparent conductive glasses on which the third electrode 33 is formed. It was applied to the outer periphery where the injection port 40 was left. Further, the same adhesive containing no beads was applied between the first electrode 31 or the second electrode 32 and the third electrode 33 so as to have a height of 40 μm to form a partition wall 36. After that, two transparent conductive glasses so that the electrode extraction portion 39 is exposed so that the first electrode 31 and the second electrode 32 face each other and the third electrodes 33 face each other. Was superposed. Next, the adhesive was cured by irradiating the third electrode 33 with UV light in a masked state so as not to hit the third electrode 33 with UV light. As a result, the substrate 37 and the substrate 38 were adhered to each other.

(5) Injection of electrolyte solution Compound 1 which is an anodic EC material and ethylviologen hexafluorophosphate which is a cathode EC material are added to a solution of 0.1M tetrabutylammonium hexafluorophosphate in propylene carbonate (PC). The salt and the solution were dissolved to prepare an electrolyte solution. At this time, the concentration of compound 1 contained in the electrolyte solution was 20 mM, and the concentration of ethyl viologen hexafluorophosphate was 20 mM. Next, after injecting this electrolyte solution (electrolyte 34) from the injection port 40, the EC element 30a was obtained by sealing 41 with the above-mentioned UV curable adhesive.

(Measurement of redox potential)
The redox potentials of the EC materials and redox substances used in this example were measured. The specific method will be described below.

A solution in which an EC material (Compound 1, ethylviologen hexafluorophosphate) and a redox substance (ferrocenedicarboxylic acid) are dissolved in a propylene carbonate (PC) solution of 0.1 M tetrabutylammonium hexafluorophosphate at 1 mM each. Was prepared. Next, CV measurement was performed using FTO as a working electrode, platinum as a counter electrode, and Ag / Ag ⁺ (PF ₆ , PC) as a reference electrode. As a result, the half-wave potentials (oxidation-reduction potentials) of the compounds were as shown in Table 1 below.

From this result, it was confirmed that in this example, the redox substance of the redox substance contained in the third electrode is more easily oxidized than the redox substance of the anodic EC material. Further, it was confirmed that the redox substance oxidant possessed by the third electrode is more easily reduced than the oxidant of the cathodic EC material.

(Durable drive of EC element)
An endurance drive experiment was conducted on the obtained EC element. First, the third electrode 33 is disconnected from the first electrode 31 and the second electrode 32, and then 1.62 V is applied between the first electrode 31 and the second electrode 32. The application of the voltage, the short circuit between the first electrode 31 and the second electrode 32, and the driving operation of the EC element including the short circuit were repeated. When the EC element is repeatedly driven, the electrolyte solution contained in the EC element becomes colored by applying a voltage between both electrodes (31, 32), and EC is caused by a short circuit between both electrodes (31, 32). The electrolyte solution contained in the element is in a decolorized state. Further, during the repeated driving of the EC element, the voltage was applied between the two electrodes (31, 32) for 5 seconds, and the short circuit between the two electrodes (31, 32) was performed for 10 seconds. On the other hand, when short-circuiting between both electrodes (31, 32), the voltage between the third electrode 33 and the first electrode 31 and the second electrode 32 is set to 0V (short-circuited state) for the latter 8 seconds. Controlled.

Decolorization defects due to charge imbalance were confirmed visually and using a spectroscope. The decolorization was confirmed using a spectroscope as follows. Specifically, light transmitted from a light source (DH-2000S manufactured by Ocean Optics) through an optical fiber through the first electrode 31 and the second electrode 32 was detected using a spectroscope (USB4000 manufactured by the same company). At this time, the EC element 30a is arranged so that the optical path of the transmitted light passes through the first electrode 31 and the second electrode 32, and the third electrode 33 deviates from the optical path.

[Comparative Example 1]
In Example 1, the EC element was produced by the same method as in Example 1 except that steps (2) and (3) were omitted when the EC element was produced. In this comparative example, the FTO film formed on the transparent conductive glass corresponds to the first electrode 31 or the second electrode 32 in FIG.

Further, in the obtained EC element, an EC element composed of an application of a voltage of 1.62 V between the first electrode and the second electrode and a short circuit between the first electrode and the second electrode. Was repeatedly driven.

(Result of durable drive of EC element)
For Example 1 and Comparative Example 1, the results of endurance driving of EC elements are summarized in Table 2 below.

When the drive operation cycle consisting of applying a voltage between both electrodes (31, 32) and short-circuiting between both electrodes (31, 32) is repeated, the EC element of Comparative Example 1 having no third electrode 33 Then, decolorization failure occurred. Specifically, in the short term, decolorization failure occurred due to the imbalance of the pale yellow anodic charge having a peak top of 445 nm. This decolorization failure is due to the radical cation of Compound 1. On the other hand, in the long term, decolorization failure occurred due to the imbalance of the blue cathodic charge having a peak top of 605 nm. This decolorization failure is due to the radical cation of ethyl viologen.

On the other hand, in the EC element of Example 1 provided with the third electrode 33 having a redox substance, no decolorization failure due to charge imbalance was observed, and the charge was effectively rebalanced. It was confirmed that it was damaged.

From the above, in the EC element having the anodic EC material and the cathodic EC material, the charge imbalance can be effectively adjusted by the third electrode 33 included in the EC element 30a by satisfying the following conditions. It was confirmed that the decolorization failure was suppressed.
(1a) Having an anodic EC material having a more positive redox potential than the redox substance possessed by the third electrode 33 (the redox substance of the redox substance possessed by the third electrode 33 is an anodic EC material. It is easier to oxidize than the reductant of.).
(1b) Having a cathodic EC material having a negative redox potential than the redox substance possessed by the third electrode 33 (the oxidant of the redox substance possessed by the third electrode 33 is a cathodic EC material. It is easier to reduce than the oxide of.).
(1c) Decolorization defects are uniformly reduced by arranging the third electrode 33 at least in a part around the first electrode 31 or the second electrode 32.
(1d) In the initial state, the third electrode 33 has an oxidized body and a reduced body of a redox substance.
(1e) Having a means for controlling the potential difference between the third electrode 33 and the first electrode 31 or the second electrode 32.
(1f) Having a means for short-circuiting between the third electrode and the first electrode 31 or the second electrode 32 during the decoloring operation.

[Example 2]
(Manufacturing of element)
The EC element 30b shown in FIG. 9 was manufactured by the following steps.

(1) Preparation of Transparent Conductive Glass Two transparent conductive glasses with a fluorine-doped tin oxide film (FTO film) used in Example 1 were prepared.

(2) Preparation of Substrate A substrate with electrodes was prepared by processing the prepared transparent conductive glass by the same method as in Example 1 (2).

(3) Preparation of Second Electrode (Porosity Electrode) In a substrate with an electrode (Substrate 38) provided with the second electrode 32, a commercially available titanium oxide nanopaste (Nanoxide-HT, manufactured by Solaronics) is used as the second electrode. After coating on the FTO film 32a along the region where 32 is provided, the titanium oxide nanopaste was fired at 500 ° C. for 30 minutes to form the second electrode 32. Next, a 5 mM aqueous solution of compound 2, which is a cathodic EC material, was immersed in the formed second electrode 32 overnight, washed with water, and dried to immobilize the cathodic EC material. The electrode 32 was formed.

(4) Preparation of First Electrode (Porous Electrode) and Third Electrode A slurry of antimony-doped tin oxide nanoparticles was prepared by the same method as in Example 1 (3). Next, in the electrode-attached substrate (substrate 37) provided with the first electrode 31 and the third electrode 33, the slurry prepared earlier is applied along the region where the first electrode 31 is provided and the region where the third electrode 33 is provided. After coating on the FTO film (31a, 33a), the coated material was fired under the condition of 500 ° C. for 30 minutes. As a result, an antimony-doped tin oxide nanoparticle film (nanoparticle film) was formed in the region where the first electrode 31 and the third electrode 33 were provided.

Next, a 1 mM aqueous solution of compound 3, which is a cathodic redox substance (EC compound), was applied to the nanoparticle film formed in the region where the third electrode 33 was provided, and the mixture was allowed to stand overnight. Next, the nanoparticle film was washed and dried to form a third electrode 33 on which compound 3, which is a redox substance, was immobilized. After that, a 5 mM ethanol solution of 1,1'-ferrocendicarboxylic acid, which is an anodic redox substance (non-EC compound), is applied to the nanoparticle film formed in the region where the first electrode 31 is provided. , I left it all night. Next, the nanoparticle film was washed with ethanol and dried to form a first electrode 31 having a redox substance.

(Evaluation of ease of oxidation / reduction)
Which of the redox substance (Compound 3) immobilized on the third electrode 33 and the cathodic EC material (Compound 2) is more likely to be oxidized was determined by the method described below. First, a curing agent (Bond Quick 5B agent) of an epoxy adhesive containing an amine as a reducing material was added to a methanol solution of Compound 2 to bring Compound 2 into a reduced state (blue). Next, a solution having the reduced compound 2 was dropped onto the antimony-doped tin oxide nanoparticle film (nanoparticle film) on which the redox substance (compound 3) was fixed under a nitrogen atmosphere. Then, the blue color derived from Compound 2 disappeared, and the nanoparticle film changed to light yellowish green instead. The change of the nanoparticle film to light yellowish green in this way means that the compound 3 has been reduced.

As a result, electron transfer from the reduced product of compound 2 (cathodic EC material) to the oxidized product of compound 3 (oxidation-reducing substance (EC-based compound)) was confirmed. Therefore, this cathodic EC material is the third. It was confirmed that the electrode 33 of the above electrode 33 is more easily oxidized than the redox substance. On the other hand, even when a 5 mM ethanol solution of ferrocene dicarboxylic acid was dropped onto the nanoparticle film on which Compound 3 was immobilized, the nanoparticle film was not colored light yellowish green. From the above, it was found that the redox substance of the third electrode 33 is more easily oxidized than the redox substance of the anodic redox substance of the first electrode 31.

(5) Adhesion of Substrate A UV-curable adhesive (TB3035B, manufactured by ThreeBond Co., Ltd.) is applied as a sealing material 35 to the transparent conductive glass on which the porous electrode serving as the second electrode 32 is formed. Was applied to the outer circumference where Next, the two transparent conductive glasses are placed so that the FTO film provided on the transparent conductive glass having the third electrode 33 and the second electrode 32 faces each other. (Substrate 37, 38) were overlapped. When the transparent conductive glass was overlapped, the first electrode 31 and the second electrode 32 overlapped with each other so that the electrode extraction portion 39 was exposed. Next, the adhesive was cured by irradiating UV light with a mask so that UV light would not hit any of the three types of porous electrodes (31, 32, 33). As a result, the substrate 37 and the substrate 38 were adhered to each other.

(6) Injection of Electrolyte Solution After injecting a propylene carbonate solution (electrolyte 34) of 0.1 M lithium perchlorate, which is an electrolyte solution, from the injection port 40, the seal 41 is sealed with the above-mentioned UV curable adhesive. , EC element 30b was obtained.

(Durable drive of EC element)
An endurance drive experiment was conducted on the obtained EC element. First, the third electrode 33 and the first electrode 31 and the second electrode 32 are disconnected from each other, and then 1.8 V between the first electrode 31 and the second electrode 32 is applied. The application of the voltage, the short circuit between the first electrode 31 and the second electrode 32, and the driving operation of the EC element including the short circuit were repeated. When the EC element is repeatedly driven, the electrolyte solution contained in the EC element becomes colored by applying a voltage between both electrodes (31, 32), and EC is caused by a short circuit between both electrodes (31, 32). The electrolyte solution contained in the element is in a decolorized state. Further, during the repeated driving of the EC element, the voltage was applied between the two electrodes (31, 32) for 3 seconds, and the short circuit between the two electrodes (31, 32) was performed for 5 seconds. On the other hand, when short-circuiting between both electrodes (31, 32), the voltage between the third electrode 33 and the first electrode 31 and the second electrode 32 is set to 0V (short-circuited state) for the latter three seconds. Controlled.

Decolorization failure due to charge imbalance was confirmed by the same method as in Example 1. When confirming the decolorization defect using a spectroscope, the EC element 30b is set so that the optical path of the transmitted light passes through the first electrode 31 and the second electrode 32 and the third electrode 33 deviates from the optical path. Placed.

[Comparative Example 2]
In the second embodiment, the EC element is manufactured by the same method as in the second embodiment except that the step (2) is omitted and the third electrode is omitted in the step (4). Made. In this comparative example, a porous film corresponding to the first electrode 31 or the second electrode 32 in FIG. 9 is formed on the FTO film formed on the transparent conductive glass.

Further, in the obtained EC element, an EC element composed of an application of a voltage of 1.8 V between the first electrode and the second electrode and a short circuit between the first electrode and the second electrode. Was repeatedly driven.

(Result of durable drive of EC element)
The results of endurance driving of EC elements for Example 2 and Comparative Example 2 are summarized in Table 3 below.

When the drive operation cycle consisting of the application of the voltage between the two electrodes (31, 32) and the short circuit between the two electrodes (31, 32) is repeated, the EC element of Comparative Example 2 having no third electrode Decolorization failure occurred. Specifically, from a short period to a long period of time, poor decolorization occurred due to imbalance of the blue-purple cathode charge having a peak top of 535 nm. This decolorization failure is due to the radical cation of Compound 2.

On the other hand, in the EC element of Example 2 provided with the third electrode 33 having a redox substance, no decolorization failure due to charge imbalance was observed, and the charge was effectively rebalanced. It was confirmed that it was damaged. In the EC element of Example 2, the third electrode 33 was colored light yellow-green during the endurance drive. By this coloring, it was more clearly confirmed that the charge was effectively rebalanced by using the third electrode 33 having the redox substance.

From the above, the following items could be confirmed.
(2a) In an EC element having an anodic redox substance possessed by the first electrode 31 and a cathodic EC material possessed by the second electrode 32, the effect of the third electrode 33 is obtained if the following conditions are satisfied. The imbalance of electric charge is adjusted, and poor decolorization is suppressed.
(2a-1) The oxidant of the redox substance possessed by the third electrode 33 is more easily reduced than the oxidant of the cathodic EC material.
(2a-2) The redox substance of the third electrode 33 is more easily oxidized than the redox substance of the anodic redox substance of the first electrode 31.
(2a-3) By arranging the third electrode 33 in at least a part around the first electrode 31 or the second electrode 32, the decolorization defect is uniformly reduced.
(2a-4) Having a means for controlling the potential difference between the third electrode 33 and the second electrode 32.
(2a-5) Having a means for short-circuiting between the third electrode 33 and the second electrode 32 during the decoloring operation.
(2b) Even when the redox substance or EC material is immobilized on the first electrode 31 or the second electrode 32, the charge imbalance can be effectively adjusted.
(2c) Since the redox substance possessed by the third electrode 33 has EC property, the charge rebalancing status can be easily confirmed.

[Example 3]
(Manufacturing of element)
The EC element 30c shown in FIG. 10 was manufactured by the following steps.

(1) Preparation of Transparent Conductive Glass First, two transparent conductive glasses (TEC15, manufactured by Nippon Sheet Glass) used in Example 1 were prepared.

(2) Preparation of Substrate Next, a part of the FTO film contained in the transparent conductive glass was removed by the same method as in Example 1 (2). As a result, the FTO film contained in the transparent conductive glass is formed by the FTO film 42 provided in the central region serving as the first electrode 31 or the second electrode 32, and the first electrode 31 or the second electrode 32. It was divided into an FTO film 33a provided with regions at both ends, which are regions for forming an electrically independent third electrode.

(3) Formation of Third Electrode An antimony-doped tin oxide nanoparticle film (nanoparticle film) was formed on the FTO film 33a in the formation region of the third electrode by the same method as in Example 1 (3).

Next, 1,1'-ferrocene dicarboxylic acid (Fc (COOH) ₂ ) was applied to the nanoparticle film of the first transparent conductive glass (base 37) by the same method as in Example 1 (3). It was fixed. Next, the compound 3 was immobilized on the nanoparticle film of the second transparent conductive glass (substrate 38) by the same method as in Example 2 (4). As a result, a third electrode on which the redox substance was immobilized, specifically, the third electrode 33b of the substrate 37 and the third electrode 33c of the substrate 38 were produced.

(4) Adhesion of substrate UV curable adhesion in which 100 μm spacer beads are mixed as a sealing material 35 on two transparent conductive glasses (substrates 37, 38) on which the third electrodes (33b, 33c) are formed. An agent (TB3035B, manufactured by ThreeBond Co., Ltd.) was applied to the outer periphery of the injection port 40. Further, the partition wall 36 was formed by the same method as in Example 1 (4). After that, two transparent sheets are exposed so that the electrode extraction portion 39 is exposed so that the first electrode 31 and the second electrode 32 face each other and the third electrodes (33b, 33c) face each other. Conductive glass was laminated. Next, the adhesive was cured by irradiating the third electrodes (33b, 33c) with UV light in a masked state so as not to be exposed to UV light. As a result, the substrate 37 and the substrate 38 were adhered to each other.

(5) Injection of electrolyte solution Compound 1 which is an anodic EC material and ethylviologen hexafluorophosphate which is a cathode EC material are added to a solution of 0.1M tetrabutylammonium hexafluorophosphate in propylene carbonate (PC). The salt and the solution were dissolved to prepare an electrolyte solution. At this time, the concentration of compound 1 which is an anodic EC material contained in the electrolyte solution was 20 mM, and the concentration of ethylviologen hexafluorophosphate which is a cathodic EC material was 20 mM. Next, after injecting this solution-like electrolyte 34 from the injection port 40, the EC element 30c was obtained by sealing 41 with the above-mentioned UV curable adhesive.

(Durable drive of EC element)
An endurance drive experiment was conducted on the obtained EC element. First, the third electrode (33b, 33c) is disconnected from the first electrode 31 and the second electrode 32, and then between the first electrode 31 and the second electrode 32. The driving operation of the EC element including the application of a voltage of 1.62 V and the short circuit between the first electrode 31 and the second electrode 32 was repeatedly performed. When the EC element is repeatedly driven, the electrolyte solution contained in the EC element becomes colored by applying a voltage between both electrodes (31, 32), and EC is caused by a short circuit between both electrodes (31, 32). The electrolyte solution contained in the element is in a decolorized state. Further, during the repeated driving of the EC element, the voltage was applied between the two electrodes (31, 32) for 5 seconds, and the short circuit between the two electrodes (31, 32) was performed for 10 seconds. On the other hand, when short-circuiting between both electrodes (31, 32), the voltage between the third electrode (33b, 33c) and the first electrode 31 and the second electrode 32 is set to 0V (for 8 seconds in the latter half). It was controlled to a short-circuit state).

Decolorization defects due to charge imbalance were confirmed visually and using a spectroscope. The decolorization was confirmed using a spectroscope as follows. Specifically, light transmitted from a light source (DH-2000S manufactured by Ocean Optics) through an optical fiber through the first electrode 31 and the second electrode 32 was detected using a spectroscope (USB4000 manufactured by the same company). At this time, the EC element is arranged so that the optical path of the transmitted light passes through the first electrode 31 and the second electrode 32, and the third electrodes (33b, 33c) deviate from the optical path.

[Comparative Example 3]
In Example 3, the EC element was produced by the same method as in Example 3 except that steps (2) and (3) were omitted when the EC element was produced. In this comparative example, the FTO film formed on the transparent conductive glass corresponds to the first electrode 31 or the second electrode 32 in FIG.

Further, in the obtained EC element, an EC element composed of an application of a voltage of 1.62 V between the first electrode and the second electrode and a short circuit between the first electrode and the second electrode. Was repeatedly driven.

(Result of durable drive of EC element)
For Example 3 and Comparative Example 3, the results of endurance driving of EC elements are summarized in Table 4 below.

When the drive operation cycle consisting of the application of the voltage between the two electrodes (31, 32) and the short circuit between the two electrodes (31, 32) is repeated, the EC element of Comparative Example 3 having no third electrode The same decoloring defect as in Comparative Example 1 occurred.

On the other hand, in the EC device of Example 3 provided with the third electrodes (33b, 33c) having a redox substance, no decolorization failure due to charge imbalance was observed. Further, in the EC element of Example 3, when the endurance drive was performed for a long period of time (1000 cycles or less), the third electrodes (33b, 33c) were colored light yellowish green. From this coloring, it was clearly confirmed that the EC element of Example 3 having the third electrode (33b, 33c) on which the redox substance was immobilized was effectively rebalanced in charge. ..

From the above, in the EC element having the anodic EC material and the cathodic EC material, the charge imbalance is effectively performed by the third electrodes (33b, 33c) of the EC element 10 by satisfying the following conditions. It was confirmed that the adjustment was performed and the decolorization failure was suppressed.
(3a) The redox of the redox substance contained in the third electrode (33b, 33c) is more easily oxidized than the redox of the anodic EC material (oxidation-reduction of the third electrode (33b, 33c)). The substance has a more negative redox potential than the anodic EC material.)
(3b) The redox substance of the third electrode (33b, 33c) is more easily reduced than the redox of the cathodic EC material (oxidation reduction of the third electrode (33b, 33c)). The substance has a more positive redox potential than the cathodic EC material.)
(3c) By arranging the third electrodes (33b, 33c) in at least a part around the first electrode 31 or the second electrode 32, the decolorization defect is uniformly reduced.
(3d) The third electrode (33b, 33c) has a plurality of redox substances.
(3e) Having a means for controlling the potential difference between the third electrode (33b, 33c) and the first electrode 31 or the second electrode 32.
(3f) Having a means for short-circuiting between the third electrode (33b, 33c) and the first electrode 31 or the second electrode 32 during the decoloring operation.

[Example 4]
(Manufacturing of element)
Using the same method as in Example 2, the EC element was prepared using Compound 4 (EC compound) instead of 1,1'-ferrocene dicarboxylic acid, which is an anodic redox substance (non-EC compound). Made. A charge balance state detecting means was installed in the manufactured EC element by the following method. An LED having an emission wavelength of 495 nm and an LED having an emission wavelength of 595 nm were installed in contact with the upper surface of the region 42 of the EC element. Each wavelength corresponds to the absorption wavelength of the anodic EC material and the cathodic EC material. Further, a photodiode was installed in contact with the lower surface of the region 42, and used as a means for detecting the absorbance ratio at each wavelength.

(Durable drive of EC element)
An endurance drive experiment was conducted on the obtained EC element. After performing a cycle test in which a rectangular wave of 1.2V for 15 seconds and 0V for 15 seconds is applied between the first electrode 31 and the second electrode 32 of the EC element for 3 days, the first electrode 1 and the first electrode 32 The second electrode 2 was short-circuited and decolorized. At this time, the amount of change in the absorbance at 495 nm / 595 nm from the initial decolorized state was + 0.002 / + 0.052, respectively, and it was found that decolorization defects in which the colored body of the cathodic EC material remained occurred. confirmed.

(Reduction of decolorization defects)
The short circuit between the first electrode 31 and the second electrode 32 of the EC element is released, and a voltage is applied between the second electrode 32 and the third electrode 33. The application time is 100 ms, and the operation is performed using the following sequence.
(I) The applied voltage starts from 0V (short circuit), and from the comparison of the absorbance before and after 200ms, the voltage is increased in 0.1V increments when there is no change due to the application or when the absorbance at 595 nm increases (second). Electrode 32 has a positive polarity, and the third electrode 33 has a negative polarity).
(Ii) When the amount of change in the absorbance at 595 nm from the initial decolorized state is 0.005 or less, the voltage application is completed.

As a result, it was confirmed that the application of the voltage was completed by the above (ii) in about 20 seconds from the start of the drive, and the decolorization defect in which the colored body of the cathode EC material remained was reduced to 1/10 or less. To. Further, by visual inspection of the EC element after the treatment, it is confirmed that the decolorization defect is uniformly reduced and almost invisible. Further, after the step of reducing the decolorization defect, the third electrode 33 was colored light yellowish green. By this coloring, it was more clearly confirmed that the charge was effectively rebalanced by using the third electrode 33 having the redox substance.

From these results, the following items could be confirmed.
(4a) In an EC element having an anodic redox substance possessed by the first electrode 31 and a cathodic EC material possessed by the second electrode 32, the effect of the third electrode 33 is obtained if the following conditions are satisfied. The imbalance of electric charge is adjusted, and poor decolorization is suppressed.
(4b) The oxidant of the redox substance possessed by the third electrode 33 is more easily reduced than the oxidant of the cathodic EC material.
(4c) By arranging the third electrode 33 in at least a part around the first electrode 31 or the second electrode 32, decolorization defects are uniformly reduced.
(4d) Having a means for controlling the potential difference between the third electrode 33 and the second electrode 32.
(4e) Even when the EC material is immobilized on the first electrode 31 and the second electrode 32, the charge imbalance can be effectively adjusted.
(4f) Since the redox substance possessed by the third electrode 33 has EC property, the charge rebalancing status can be easily confirmed.
(4g) Based on the detected charge balance state of the EC element, the potential difference between the third electrode and the second electrode is controlled to effectively reduce the remaining colored material due to the charge imbalance of the EC element. What you can do.
(4h) After applying the voltage based on the voltage control step, the colored body remaining due to the charge imbalance of the EC element is determined by determining the execution of the additional voltage application based on the detected charge balance state of the electrochromic element. Can be effectively reduced.

1: 1st electrode, 2: 2nd electrode, 3: 3rd electrode, 4: electrolyte, 5: sealing material, 6: partition wall, 7 (8): substrate, 10: EC element

Claims (28)

It has a first electrode, a second electrode, and a third electrode, and at least one of the first electrode and the second electrode is transparent, and the first electrode An electrochromic element having an electrolyte, an anodic organic electrochromic compound, and a cathodic oxidation-reducing substance between the second electrode.
The electrolyte is arranged between the first electrode and the third electrode, and at least one of the second electrode and the third electrode.
The third electrode further comprises a non-electrochromic redox material.
An electrochromic element, characterized in that the reduced form of the redox substance contained in the third electrode is more easily oxidized than the reduced form of the anodic organic electrochromic compound. It has a first electrode, a second electrode, and a third electrode, and at least one of the first electrode and the second electrode is transparent, and the first electrode An electrochromic element having an electrolyte, a cathodic organic electrochromic compound, and an anodic oxidation-reducing substance between the second electrode.
The electrolyte is arranged between the first electrode and the third electrode, and at least one of the second electrode and the third electrode.
The third electrode further comprises a non-electrochromic redox material.
An electrochromic element, characterized in that an oxidant of a redox substance contained in the third electrode is more easily reduced than an oxidant of the cathodic organic electrochromic compound. It has a first electrode, a second electrode, and a third electrode, and at least one of the first electrode and the second electrode is transparent, and the first electrode An electrochromic element having an electrolyte, an anodic organic electrochromic compound, and a cathodic organic electrochromic compound between the second electrode.
The electrolyte is arranged between the first electrode and the third electrode, and at least one of the second electrode and the third electrode.
The third electrode has a redox substance and
The redox substance of the third electrode is more easily oxidized than the redox compound of the anodic organic electrochromic compound.
An electrochromic element, characterized in that an oxidant of a redox substance contained in the third electrode is more easily reduced than an oxidant of the cathodic organic electrochromic compound. An electrochromic device having a first electrode, a second electrode, and a third electrode, and at least one of the first electrode and the second electrode is transparent.
An electrolyte is arranged between the first electrode and the third electrode, and at least one of the second electrode and the third electrode.
The third electrode has a redox substance and
The electrolyte, the anodic organic electrochromic compound, and the cathodic redox substance are provided between the first electrode and the second electrode, and the redox possessed by the third electrode. The reduced form of the substance is more easily oxidized than the reduced form of the anodic organic electrochromic compound.
Or
The electrolyte, the cathodic organic electrochromic compound, and the anodic redox substance are provided between the first electrode and the second electrode, and the redox possessed by the third electrode. The oxidant of the substance is more easily reduced than the oxidant of the cathodic organic electrochromic compound.
Wherein a third electrode, characterized in that it is arranged outside the optical path of light transmitted through at least one of the first electrode or the second electrode, elect runner electrochromic device. An electrochromic device having a first electrode, a second electrode, and a third electrode, and at least one of the first electrode and the second electrode is transparent.
An electrolyte is arranged between the first electrode and the third electrode, and at least one of the second electrode and the third electrode.
The third electrode has a redox substance and
The electrolyte, the anodic organic electrochromic compound, and the cathodic redox substance are provided between the first electrode and the second electrode, and the redox possessed by the third electrode. The reduced form of the substance is more easily oxidized than the reduced form of the anodic organic electrochromic compound.
Or
The electrolyte, the cathodic organic electrochromic compound, and the anodic redox substance are provided between the first electrode and the second electrode, and the redox possessed by the third electrode. The oxidant of the substance is more easily reduced than the oxidant of the cathodic organic electrochromic compound.
Wherein a third electrode, characterized in that it is arranged at least partly around the first electrode or the second electrode, elect runner electrochromic device. An electrochromic device having a first electrode, a second electrode, and a third electrode, and at least one of the first electrode and the second electrode is transparent.
An electrolyte is arranged between the first electrode and the third electrode, and at least one of the second electrode and the third electrode.
The third electrode has a redox substance and
The electrolyte, the anodic organic electrochromic compound, and the cathodic redox substance are provided between the first electrode and the second electrode, and the redox possessed by the third electrode. The reduced form of the substance is more easily oxidized than the reduced form of the anodic organic electrochromic compound.
Or
The electrolyte, the cathodic organic electrochromic compound, and the anodic redox substance are provided between the first electrode and the second electrode, and the redox possessed by the third electrode. The oxidant of the substance is more easily reduced than the oxidant of the cathodic organic electrochromic compound.
Wherein a third electrode, characterized by having two or more redox agents, elect runner electrochromic device. An electrochromic device having a first electrode, a second electrode, and a third electrode, and at least one of the first electrode and the second electrode is transparent.
An electrolyte is arranged between the first electrode and the third electrode, and at least one of the second electrode and the third electrode.
The third electrode has a redox substance and
The electrolyte, the anodic organic electrochromic compound, and the cathodic redox substance are provided between the first electrode and the second electrode, and the redox possessed by the third electrode. The reduced form of the substance is more easily oxidized than the reduced form of the anodic organic electrochromic compound.
Or
The electrolyte, the cathodic organic electrochromic compound, and the anodic redox substance are provided between the first electrode and the second electrode, and the redox possessed by the third electrode. The oxidant of the substance is more easily reduced than the oxidant of the cathodic organic electrochromic compound.
And further comprising a means for detecting the charge balance state of the electrochromic device, elect runner electrochromic device. The following formula (I) is satisfied between the redox potential E _EC (A) of the anodic organic electrochromic compound and the redox potential E _RO of the redox substance possessed by the third electrode. The electrochromic element according to claim 1 or 3, which is characterized.
E _RO <E _EC (A) (I) The following formula (II) is satisfied between the redox potential E _EC (C) of the cathodic organic electrochromic compound and the redox potential E _RO of the redox substance possessed by the third electrode. The electrochromic element according to claim 2 or 3, which is characterized.
E _RO > E _EC (C) (II) The redox potential E _EC of the anode organic electrochromic compound of (A), redox potential E _EC (C) of the cathodic organic electrochromic compounds of oxidation of the redox substance the third electrode has The electrochromic element according to claim 3, wherein the following formula (III) is satisfied between the reduction potential E _RO and the reduction potential E _RO .
E _EC (C) <E _RO <E _EC (A) (III) The third electrode is provided in any one of claims 1 to 10 , wherein the third electrode is arranged outside the optical path of light transmitted through at least one of the first electrode and the second electrode. The electrochromic element described. A claim, wherein at least one of the organic electrochromic compounds contained between the first electrode and the second electrode is immobilized on the first electrode or the second electrode. The electrochromic element according to any one of 1 to 11 . The electrochromic according to any one of claims 1 to 12 , wherein the third electrode is arranged at least around the first electrode or the second electrode. element. The electrochromic element according to any one of claims 1 to 13 , wherein the redox state of the redox substance possessed by the third electrode is a state in which an oxidant and a reduced substance are mixed. The electrochromic device according to any one of claims 1 to 14 , wherein the third electrode has two or more kinds of redox substances. The invention according to any one of claims 1 to 15 , further comprising a means for controlling a potential difference between the first electrode or the second electrode and the third electrode. Electrochromic element. 1 to 1, wherein the electrochromic element further includes a means for short-circuiting between the first electrode or the second electrode and the third electrode during the decoloring operation of the electrochromic element. 16. The electrochromic device according to any one of 16 . The electrochromic device according to any one of claims 1 to 17 , further comprising a means for detecting a charge balance state of the electrochromic device. The third electrode according to any one of claims 1 to 18 , wherein the third electrode can be electrically connected to the first electrode or the second electrode via the electrolyte. Electrochromic element. The method for driving an electrochromic element according to any one of claims 1 to 19 , wherein at least one of the first electrode and the second electrode is based on the detected charge balance state of the electrochromic element. A method for driving an electrochromic element, which comprises a step of controlling a potential difference between the electrode and the third electrode. The electrochromic according to claim 20 , wherein after controlling the potential difference based on the step of controlling the potential difference, the execution of additional potential difference control is determined based on the detected charge balance state of the electrochromic element. How to drive the element. The electrochromic device according to any one of claims 1 to 19 .
An optical filter comprising an active element connected to the electrochromic element. An imaging optical system with multiple lenses and
A lens unit comprising the optical filter according to claim 22 . An imaging optical system with multiple lenses and
The optical filter according to claim 22 and
An image pickup apparatus comprising: an image pickup element that receives light transmitted through the optical filter. The imaging device according to claim 24 , wherein the imaging optical system is removable. A pair of transparent boards and
The electrochromic element according to any one of claims 1 to 19 , which is arranged between the pair of transparent substrates.
A window material comprising an active element connected to the electrochromic element. An electrochromic device having a first electrode, a second electrode, and a third electrode, and at least one of the first electrode and the second electrode is transparent.
An electrolyte is arranged between the first electrode and the third electrode, and at least one of the second electrode and the third electrode.
The third electrode has a redox substance and
The electrolyte, the anodic organic electrochromic compound, and the cathodic redox substance are provided between the first electrode and the second electrode, and the redox possessed by the third electrode. The reduced form of the substance is more easily oxidized than the reduced form of the anodic organic electrochromic compound.
Or
The electrolyte, the cathodic organic electrochromic compound, and the anodic redox substance are provided between the first electrode and the second electrode, and the redox possessed by the third electrode. A method for driving an electrochromic element in which an oxidant of a substance is more easily reduced than an oxidant of the cathodic organic electrochromic compound .
It is characterized by having a step of controlling a potential difference between at least one of the first electrode and the second electrode and the third electrode based on the detected charge balance state of the electrochromic element. How to drive an electrochromic element. 27. The electrochromic according to claim 27 , wherein after controlling the potential difference based on the step of controlling the potential difference, it is determined to perform additional potential difference control based on the detected charge balance state of the electrochromic element. How to drive the element.

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