JP6752632B2 - Electrochromic elements, optical filters, lens units, imaging devices and window materials - Google Patents

Description

The present invention relates to an electrochromic element 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 contrast of decolorization.

In such an EC device, suppressing changes in optical characteristics with the passage of 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 the 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 ratio of coloring to be performed is smaller than the ratio of coloring 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 includes a first electrode, a second electrode, and a carrier, and at least one of the first electrode and the second electrode is used. An electrochromic element that is transparent and has an electrolyte, an anodic organic electrochromic compound, and a cathodic redox substance between the first electrode and the second electrode.
The electrolyte, the anodic organic electrochromic compound, and the cathodic redox substance are mixed.
The electrolyte is in contact with the first electrode, the second electrode and the carrier.
The carrier further comprises a redox substance and
The reduced form of the redox substance contained in the carrier is characterized in that it is more easily oxidized than the reduced form 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 carrier, and at least one of the first electrode and the second electrode is used. An electrochromic element that is transparent and has an electrolyte, a cathodic organic electrochromic compound, and an anodic redox substance between the first electrode and the second electrode.
The electrolyte, the cathodic organic electrochromic compound, and the anodic redox substance are mixed.
The electrolyte is in contact with the first electrode, the second electrode and the carrier.
The carrier further comprises a redox substance and
The oxidant of the redox substance contained in the carrier is more easily reduced than the oxidant of the cathodic organic electrochromic compound.

A third aspect of the electrochromic element of the present invention includes a first electrode, a second electrode, and a carrier, and at least one of the first electrode and the second electrode is used. An electrochromic element that is transparent and has an electrolyte, an anodic organic electrochromic material, and a cathodic organic electrochromic compound between the first electrode and the second electrode.
The electrolyte, the anodic organic electrochromic compound, and the cathodic organic electrochromic compound are mixed.
The electrolyte is in contact with the first electrode, the second electrode and the carrier.
The carrier has a redox substance and
The reduced form of the redox substance contained in the carrier is more easily oxidized than the reduced form of the anodic organic electrochromic compound.
The oxidant of the redox substance contained in the carrier is more easily reduced than the oxidant 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. (A) is a diagram showing an absorption spectrum of an EC element that does not correspond to the present invention, and (b) is a diagram showing an absorption spectrum of an EC element of the present 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 carrier. 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 electrolyte and two kinds of redox substances (including organic electrochromic compounds) which are any of the above (i) to (iii) are mixed. In the present invention, the electrolyte is in contact with the first electrode, the second electrode and the carrier. In the present invention, the carrier 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 contained in the carrier is a reduction of the anodic organic electrochromic compound. It is more easily oxidized than the body. 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 carrier is a cathodic organic electrochromic compound. It is more easily reduced than the oxidant.

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. 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 element is not driven, but is in an oxidized state when the element 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. 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. Oxidized substances, reduced substances Oxidized substances and reduced substances, 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, a ferrocene having a divalent iron (neutral form 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 carrier The carrier constituting the EC element of the present invention has a redox substance. Here, the fact that the carrier has a redox substance means that the redox substance is directly or indirectly immobilized on the carrier. Here, when the redox substance is directly immobilized on the carrier, the redox substance is in a state of being immobilized on the carrier by a physical or chemical factor without interposing other substances. On the other hand, when the redox substance is indirectly immobilized on the carrier, the redox substance is physically or chemically immobilized on the carrier, for example, via the substance immobilized on the carrier. It has become.

Here, the carrier is a member that does not transfer and receive electric charges to an external circuit, and has a redox substance in a state that enables transfer of electric charges to and from the EC material contained in the electrolyte. Is. In this respect, it is different from an electrode that transfers an electric charge to and from an EC material contained in an electrolyte and transfers an electric charge to an external circuit. On the other hand, even if it is a material generally used as an electrode material, if the material has a redox substance and the material is not in a state where electric charge can be transferred to an external circuit, it should be treated as a carrier. Can be done. The redox substance contained in this carrier does not positively contribute to the decolorization step when the device is driven, but functions to balance the electric charges described later.

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 complementary EC elements. 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 oxide (decolorized state) of the cathodic EC material, and C ⁻ is a reduced product (colored state) of the cathodic EC material.

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 occurs at the first electrode 1. At the second electrode 2, the reduction reaction of the cathodic EC material shown in (β) below 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 bleaching the EC cell, a bleaching voltage (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. As a result, as shown by the arcuate arrow in FIG. 1 (b), the reverse reaction of the reaction shown in FIG. 1 (a) proceeds. 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 due to some steps other than the normal coloring / bleaching step. 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, an 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 having a first electrode 1 and a carrier 3 (first substrate 7), and a substrate having a second electrode 2 and a carrier 3 (second substrate). 8) and. 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 carrier 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 restricting the transport of substances between the first electrode 1 and the second electrode 2 and the carrier 3, the partition wall 6 shown in FIG. 2 is optionally used as the first electrode. It may be provided between the first and second electrodes 2 and the carrier 3. Further, in the EC element of the present invention, an anodic redox substance and a cathodic redox substance are mixed with the electrolyte 4, respectively. As used herein, "mixing" preferably means dissolution. In the present invention, at least one of the anodic redox substance and the cathodic redox substance mixed with the electrolyte 4 is an EC material.

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

(1) Substrates 7, 8 / electrodes 1, 2,
(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 imaging 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 imaging 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 materials of the first electrode 1 and the second electrode 2 are stably present 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) Carrier The EC element of the present invention has a carrier 3 in addition to the electrodes (1, 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 it is an anodic or cathodic charge imbalance. 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 and the decolorization failure (remaining disappearance) is suppressed. Only the EC material of the opposite polarity is colored, and it is not an effective suppression measure. Here, the "EC material having opposite polarity" 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.

Therefore, in the present invention, the carrier 3 having the redox substance is used, and both are used during 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. It was decided to adjust the amount of electric charge used in the redox reaction passing through the 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 carrier 3, a member other than an electrode having a redox substance necessary for performing charge rebalancing is used. As the redox substance contained in the carrier 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. Of these, organic compounds are preferably used because of their compatibility with the environment in which the EC material used in combination is used. Further, in the present invention, the redox substance contained in the carrier 3 may be one kind or two or more kinds.

It is preferable that the redox state of the redox substance contained in the carrier 3 is a state in which the oxide / reduced substance is mixed. This can be explained as follows. When the redox state of the redox substance contained in the carrier 3 is only the oxidant and only the reduced substance, the redox substance has a polarity charge that causes either an anodic or cathodic charge imbalance. It 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. 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. 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 carrier 3 may be an EC-based redox substance or a non-EC-based redox substance. If the carrier 3 is present in the optical path of light incident on the EC element 10, it is preferable to use a non-EC redox substance in order to reduce the influence of light absorption by the redox substance. .. On the other hand, when the carrier 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 is rebalanced depending 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.

Examples of the redox substance contained in the carrier 3 include metal complex compounds and EC-based materials. Specific examples of the metal complex compound include metal complexes in which the metal ions are Os, Fe, Ru, Co, Cu, Ni, V, Mo, Cr, Mn, Pt, Rh, Pd, Ir and the like. it can. 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. As the EC material, an EC material described later can be particularly preferably used.

The relationship between the redox substance contained in the carrier 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 carrier 3 is more easily oxidized than the redox product of the anodic EC material. When the cathodic EC material is contained, the redox substance oxidant of the carrier 3 is more easily reduced than the oxidant of the cathodic EC material. When both the anodic EC material and the cathodic EC material are included, the redox of the redox substance contained in the carrier 3 is more easily oxidized than the redox of the anodic EC material, and the redox of the carrier 3 The oxidant of the substance is more likely to be 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 contained in the carrier 3, the redox substance of the redox substance of the carrier 3 is more easily oxidized than the redox substance of the anodic EC material. You will need it. 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 carrier 3, it is necessary that the oxidant of the redox substance of the carrier 3 is more easily reduced than the oxidant of the cathodic EC material. become.

Further, the redox substance contained in the carrier 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 is contained in the carrier 3 (immobilization). The following effects are achieved by setting the state. By having (immobilizing) the carrier 3, the redox substance is usually contained in the first electrode 1 or the second electrode 2 for driving the EC element, that is, for advancing the electrochemical reaction in the electrode of the EC material. Never reach. 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 anode EC material and / or the redox of the redox is more likely to be reduced than the oxide of the cathode 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, when the redox substance of the carrier 3 reaches the other electrodes (1, 2), the redox or oxidant of the redox substance reacts more easily than the decolorizing substance of the EC material. This is because the electric charge that should be used for the reaction of the EC material is easily 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 4 in the electrolyte, 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 carrier 3 so as to have a redox substance and the carrier 3 to be out of the optical path of light passing through the EC element.

In the present invention, when the EC element 10 contains an anodic EC material, the redox substance of the carrier 3 is more easily oxidized than the redox material of the anodic EC material. Further, when the cathodic EC material is contained in the EC element 10, the redox substance oxidant of the carrier 3 is more easily 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 the electrolyte contains an anodic EC material, a redox of an oxidation-reducing substance is charged, and if the electrolyte contains a cathodic EC material, at least an oxide of an acid-reducing substance is charged. As a result of adding the redox substance, if the colored body, that is, the oxidant of the anodic EC material or the reduced product of the cathodic EC material is decolorized, 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 reduced product of the redox substance contained in the carrier 3 is more easily oxidized than the reduced product 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 carrier 3 is more easily reduced than the oxidant of the cathodic EC material. Further, when the redox substance contained in the carrier 3 is EC-based, 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 carrier 3 does not have. Further, the color change of the EC material is a change in absorption of the EC-based redox substance possessed by the carrier 3.

(1-3b) Electron transfer reaction method (direct, via carrier 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 carrier 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 carrier having a corresponding redox substance. As a result, if the colored body, that is, the oxidant 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 via the carrier 3 has proceeded. Specifically, in the case of an anodic EC material, electrons are transferred from the reduced body of the redox substance possessed by the carrier 3 to the carrier 3, and the anodic EC material is oxidized by receiving electrons from the carrier 3. It changes from the body (colored state) to the reduced body (decolorized state). The occurrence of this reaction means that the reduced product of the redox substance contained in the carrier 3 is more easily oxidized than the reduced product of the anodic EC material. On the other hand, in the case of a cathodic EC material, electron transfer occurs from the carrier 3 to the oxidant of the redox substance possessed by the carrier 3, and electron transfer from the cathodic EC material to the carrier 3. As a result, the cathodic EC material changes from a reduced body (colored state) to an oxidized body (decolorized state). The occurrence of this reaction means that the oxidant of the redox substance contained in the carrier 3 is more easily reduced than the oxidant of the cathodic EC material. When the redox substance contained in the carrier 3 has EC properties, 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 of the carrier 3 is more negative than the half-wave potential of the redox reaction corresponding to the oxidation reaction in which the anodic EC material is reversibly colored. Being on the side means the following. That is, it means that the reduced product of the redox substance contained in the carrier 3 is more easily oxidized than the reduced product of the anodic EC material. Further, in this case, it is preferable that 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 carrier 3.
E _RO <E _EC (A) (I)

The half-wave potential of the reversible redox reaction of the redox substance of the carrier 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. Means the following. That is, it means that the oxidant of the redox substance contained in the carrier 3 is more easily reduced than the oxidant of the cathodic EC material. Further, in this case, it is preferable that 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 carrier 3.
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, between the redox potential E _EC of the anode of the EC material (A), the redox potential of the cathode of the EC material E _EC (C), a redox potential E _RO oxidation reduction material having a carrier 3 It is particularly preferable that the following formula (III) is satisfied.
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 carrier constituting the EC element of the present invention can be used as it is. Further, as the solvent and the support used when performing the cyclic voltanmogram measurement, it is preferable to use the solvent used for the EC element. 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 carrier 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 (including the EC material). ), It is desirable that the relationship is as follows.

When an anodic EC material and an EC or non-EC cathodic redox substance are used, the redox substance contained in the carrier 3 is higher than that of the cathodic redox substance. Is also preferably easily reduced. When a cathode EC material and an EC or non-EC anodic redox substance are used, the redox substance of the carrier 3 is a redox substance of the anodic redox substance. It is preferable that it is easily oxidized.

On the other hand, when the redox substance of the carrier 3 is used together with the cathodic redox substance, the redox substance of the redox substance of the carrier 3 is less likely to be reduced than the redox substance of the cathodic redox substance. Consider the case. In this case, an imbalance of cathodic charges occurs in the EC element 10, and when a reduced substance of the cathodic redox substance remains in the element, the redox substance of the carrier 3 is changed from the cathodic redox substance. No electron transfer to the oxidant occurs. This is because the redox substance contained in the carrier 3 does not contribute to the charge rebalancing. Further, when the redox substance of the carrier 3 is used together with the anodic redox substance, consider the case where the redox of the redox substance of the carrier 3 is less likely to be oxidized than the redox of the anodic redox substance. .. In this case, an anodic charge imbalance occurs in the EC element 10, and when an oxidant of the redox substance remains in the element, the anodic redox substance receives electrons from the redox substance of the carrier 3. Can't. This is because the redox substance contained in the carrier 3 does not contribute to the charge rebalancing.

The method for determining the ease of oxidation or reduction between the anodic redox substance / cathodic redox substance and the redox substance contained in the carrier 3 can be considered in the same manner as the above EC material. 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 carrier 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 carrier 3 is basically large within a range in which there is no problem in practical use of the device. A promising method for increasing the amount of redox substance immobilized (contained) on the carrier 3 is to increase the surface area of the electrode. It is preferable that the carrier 3 has a porous structure in order to realize an increase in the surface area of the carrier 3 with an element size suitable for an actual configuration. 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.

The constituent material of the carrier 3 is not particularly limited, but a material having or capable of forming a porous structure is preferable. Examples of the material having or being able to form a porous structure include inorganic oxides (for example, metal oxides, silicon oxide, carbon materials, metal materials), and organic compounds (for example, polymers). A hybrid material in which a plurality of types of these materials (for example, one type of inorganic compound and one type of organic compound) are combined, for example, a film-like material can be used. Further, when the carrier 3 is arranged outside the optical path taken in by the EC element, a material that scatters light, a non-transparent porous material, a carbon material, a metal material such as platinum or titanium, or the like can be used. The porous structure of the carrier 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 carrier 3 is preferably 100 nm or more, preferably 1 μm or more.

Next, the arrangement of the carrier 3 will be described below. The EC element of the present invention has two types of electrodes (1, 2) and a carrier 3, of which the electrodes (1, 2) are generally known as the electrode arrangement of the EC element. Can be used. As a typical example, an arrangement in which a distance of about 1 μm to 500 μm, which will be described later, is provided so that the first electrode 1 and the second electrode 2 formed on the substrate (7, 8) face each other. There is a method. The arrangement of the carrier 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 transmission 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 and is emitted through the other electrode. On the other hand, in the case of a reflective 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 carrier 3 constituting the EC element of the present invention is arranged in this optical path, the carrier 3 may also be an element for reducing the transmittance of the EC element. Specifically, it is as described below. The carrier 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 carrier 3 has a porous structure. It is desirable to do. 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 carrier 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 image pickup device, it is used for necessary imaging in the entire region of a light receiving element (for example, a CCD sensor or a 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 carrier 3 outside the optical path, the constituent materials of the carrier 3 can be selected with a high degree of freedom as described above. Further, even when the redox substance contained in the carrier 3 is EC-based, it can be used without any problem.

Next, the arrangement position of the carrier 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 uniformly performed on the same electrode. .. From this point of view, it is preferable that the carrier 3 is arranged in at least a part around the first electrode 1 and / or the second electrode 2, for example, as shown in FIG. 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 carrier 3 may be arranged so as to surround the first electrode 1 and the second electrode 2 as shown in FIG. 3A, or may be arranged so as to surround the first electrode 1 and the second electrode 2 as shown in FIG. 3B. It may be arranged so as to surround three sides of 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 carrier 3 electrochemically decolorizes the EC material remaining as a colorant on the first electrode 1 and / or the second electrode 2 when the EC element 10 has a decolorization defect. It can function as a holding place for electric charges. Therefore, it is desirable that the EC material that is normally colored at the time of coloring or the like does not reach the carrier 3. In the EC element 10 of the present invention, since the EC material can be freely diffused in the electrolyte 4, when it reaches the carrier 3, the colored body may 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 carrier 3. Specifically, it is possible to arrange a structure that reduces the transport of substances, such as the partition wall 6 shown in FIG. 2, which takes a distance. In the former case, specifically, the distance between the first electrode 1 and / or the second electrode 2 and the carrier 3 is larger than the distance between the first electrode 1 and the second electrode 2. It is possible to make it larger. Further, as the latter, a method of forming a partition wall 6 having an opening 6a shown in FIG. 2 between the first electrode 1 and / or the second electrode 2 and the carrier 3 can be mentioned. It is preferable that the partition wall 6 itself has a porous structure. The reason why the partition wall 6 having the opening 6a is provided is that it is necessary to secure the substance transport between the first electrode 1 and / or the second electrode 2 and the carrier 3 in order for the carrier 3 to function effectively. Is.

The carrier 3 can be formed, for example, through the following steps.
(A) A step of removing a part of the conductive layer of the conductive substrate forming the first electrode 1 or the second electrode 2 by etching or the like.
(B) A step of forming a carrier 3 which is a porous film in a region from which the conductive layer has been removed.
(C) A step of immobilizing a redox substance on the carrier 3.

Any of the steps (A), (B) and (C) may be performed first. Further, the carrier 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 are arranged. It may be formed on both of the substrates on which 2 is arranged.

(2) 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-based or 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 a 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. As the material of the spacer 5, an inorganic material such as silica beads or glass fiber or an organic material such as polyimide, polytetrafluoroethylene, polydivinylbenzene, fluororubber, or epoxy resin can be used. The spacer 5 makes it possible to define and hold the distance between the first electrode 1 and the second electrode 2 constituting the EC element 10.

(3) 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 mixed with the electrolyte 4 between the first electrode 1 and the second electrode 2. Has. In the present invention, the anodic organic EC material and the cathodic organic EC material are preferably dissolved in the electrolyte 4.

The fact that the anodic organic EC material and the cathodic organic EC material are dissolved in the electrolyte is 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) When immobilization is performed, structural ingenuity and manufacturing processes are often required for both the EC material to be immobilized and the electrode serving as the immobilization carrier, but these are not provided.

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. Among them, 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 an 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.

(4) EC Material The EC material used in the EC device of the present invention is a low-molecular-weight organic compound of a type that is colored by applying an electrical stimulus from the outside. 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) are used. 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.

8. Charge balance adjustment mechanism The EC element 10 of the present invention adjusts the charge balance of the EC element 10 by using the carrier 3. In the EC element 10 of the present invention, the carrier 3 has a redox substance, and the ease of oxidation or reduction with the EC material is defined. Therefore, the charge can be rebalanced by utilizing the ease of oxidation or reduction. Hereinafter, a specific description will be given. In order to decolorize the EC element 10, for example, when the first electrode 1 and the second electrode 2 are short-circuited, the anodic EC material contained in the EC element remains colored. Consider the remaining state (as an oxide). In this case, an anodic charge imbalance has occurred. At this time, if the anodic EC material of the oxidant moves to the vicinity of the carrier 3 having the redox substance, and the redox substance possessed by the carrier 3 is in a state where electric charges can be transferred directly or through the carrier 3, the following become that way. Due to the ease of oxidation and reduction between compounds, electrons are supplied from the redox substance of the redox substance of the carrier 3 to the anodic EC material of the oxidant, so that the above-mentioned anodic charge imbalance is achieved. It will be resolved. On the contrary, consider a state in which the cathodic EC material contained in the EC element remains colored (reduced). In this case, the cathodic charge is imbalanced. At this time, when the cathode EC material of the reducing body moves to the vicinity of the carrier 3 having the redox substance, and the redox substance possessed by the carrier 3 is in a state where charge can be transferred directly or through the carrier 3. It becomes as follows. Due to the ease of oxidation / reduction between compounds, electrons are supplied from the cathodic EC material of the reducer to the redox of the redox substance of the carrier 3, so that the cathodic charge imbalance described above is caused. It will be resolved. For the same reason, even in the case of the EC element 10 having the anodic EC material and the cathodic EC material, the charge imbalance can be effectively eliminated by using the redox substance contained in the carrier 3. As described above, in the EC element 10 of the present invention, the electric charge can be rebalanced depending on the ease of oxidation / reduction.

9. Effect In the present invention, by using the carrier 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, the ratio of the colorant of the anodic EC material to the colorant of the cathodic EC material cannot be modified.

On the other hand, the method of the present invention, that is, the method using the carrier 3, rebalances the broken charge balance between the display electrodes by using the carrier 3 having a redox substance for the charge adjustment. .. 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 carrier 3 having the redox substance. In this case, when the EC material is colored, only the first electrode 1 and the second electrode 2 are driven without using the carrier 3, so that the excessive coloring state due to the charge imbalance is not reproduced. Therefore, the ratio of the colored body of the above-mentioned EC material can be corrected by using the method of the present invention.

Hereinafter, description will be made with reference to the drawings. FIG. 4A is a diagram showing an absorption spectrum of an EC element that does not correspond to the present invention, and FIG. 4B is a diagram showing an absorption spectrum of an EC element of the present invention. 4 (a) and 4 (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 characteristic absorption peaks at 455 nm and 500 nm, and the cathodic EC material has characteristic absorption peaks 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. 4A. 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. 4A and 4B. The absorption spectrum of the EC element at the time of coloring at this time is the spectrum c in FIGS. 4 (a) and 4 (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. 4 (b). Since the spectrum d in FIG. 4B is in good agreement with the spectrum a in FIG. 4A, it can be seen in FIG. 4 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 carrier 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 the increase in power consumption and the decrease in response speed in the coloring operation of a normal EC element, and the change in the ratio of the colored body of the anodic EC material to the colored body of the cathodic EC material.

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. 5 is a schematic view showing an example of an embodiment in the imaging device of the present invention. The image pickup device 100 of FIG. 5 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. 5, 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. 5, 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. 5, 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. 5 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. 5, 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 (102 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. 5, 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. 5, 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.

6A and 6B are schematic views showing an example of an embodiment of the window material of the present invention, FIG. 6A is a perspective view, and FIG. 6B is a cross-sectional view taken along the line XX'of FIG. 6A. is there.

The window material 111 of FIG. 6 is a dimming window, and includes an EC element 114 (however, the carrier 3 is not shown), a transparent plate 113 that sandwiches the EC element 114, and a frame 112 that surrounds and integrates the entire EC element 114. Consists of. The driving means of the window material 111 of FIG. 6 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. 6, 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. 6, 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. 6, 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 redox substance, was synthesized based on the literature (Solar Energy Materials and Solar Cells, Vol. 57 (1999), pp. 107-125). Compound 2 is a compound having EC properties.

[Example 1]
(Manufacturing of element)
The EC element 30a shown in FIG. 7 was manufactured by the following steps.

(1) Preparation of Transparent Conductive Glass First, two transparent conductive glasses on which a tin-doped indium oxide (ITO) film was formed were prepared.

(2) Preparation of Substrate Next, using a commercially available ITO etching solution, the ITO film outside the position of α in FIG. 7A was partially removed. The ITO film 42 remaining by this operation was used as the first electrode 31 or the second electrode 32.

(3) Preparation of Carrier A commercially available titanium oxide nanopaste (Nanoxide-HT, manufactured by Solaronics) was applied to the region of the substrate (37, 38) from which the ITO film had been removed, and fired at 350 ° C. for 60 minutes. .. Since the titanium oxide particle film formed by this firing is not electrically connected to the external circuit, it functions not as an electrode but as a carrier 33. Next, the formed carrier 33 was coated with an ethanol solution of 5 mM 1,1'-ferrocene dicarboxylic acid (Fc (COOH) ₂ ) and allowed to stand overnight. Next, the carrier 33 was washed with ethanol and dried. Next, an amount corresponding to half of the ferrocene dicarboxylic acid immobilized on the carrier 33 was oxidized with nitrosyl tetrafluoroborate. As a result, the ratio of the oxidized form of the 1,1'-ferrocenedicarboxylic acid immobilized on the carrier 33 to the reduced form was set to about 1: 1. As a result, the redox state of the redox substance contained in the carrier was changed to a state in which the oxide and the reduced body were mixed. As a result, a carrier 33 in which a non-EC redox substance (ferrocene dicarboxylic acid) was immobilized on the titanium oxide nanoparticle film was formed.

(4) Adhesion of Substrate A UV-curable adhesive (TB3035B, manufactured by ThreeBond Co., Ltd.) in which 100 μm spacer beads are mixed as a sealing material 35 with two transparent conductive glasses on which a carrier 33 is formed is applied to an injection port 40. Was applied to the outer circumference where Further, the same adhesive containing no beads was applied between the first electrode 31 or the second electrode 32 and the carrier 33 so as to have a height of 40 μm to form a partition wall 36. After that, two transparent conductive glasses were laminated so that the electrode extraction portion 39 was exposed so that the first electrode 31 and the second electrode 32 faced each other and the carriers 33 faced each other. .. Next, the adhesive was cured by irradiating the carrier 33 with UV light in a masked state so as not to expose the carrier 33 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). An electrolyte solution was prepared by dissolving the salt. 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 ITO 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 reduced product of the redox substance contained in the carrier is more easily oxidized than the reduced product of the anodic EC material. It was also confirmed that the redox substance of the carrier is more easily reduced than the oxide of the cathodic EC material.

(Durable drive of EC element)
An endurance drive experiment was conducted on the obtained EC element. Specifically, the EC element is composed of an application of a voltage of 1.62 V between the first electrode 31 and the second electrode 32 and a short circuit between the first electrode and the second electrode. The drive was repeated. During this repeated driving, the voltage application (driving time for coloring state) was set to 5 seconds, and the short circuit (driving time for decolorizing state) was set to 600 seconds.

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 carrier 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 ITO film formed on the transparent conductive glass corresponds to the first electrode 31 or the second electrode 32 in FIG. 7.

(Result of durable drive of EC element)
The results of endurance driving of EC elements for Example 1 and Comparative Example 1 are summarized in Table 2 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 1 having no carrier 33 is decolorized. A defect has 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 device of Example 1 provided with the carrier 33 having a redox substance, no decolorization failure due to charge imbalance was observed, and charge rebalancing was effectively performed. It was confirmed that.

From the above, in the EC element having the anodic EC material and the cathodic EC material, the charge imbalance is effectively adjusted by the carrier 33 included in the EC element 30a by satisfying the following conditions, and the charge imbalance is eliminated. It was confirmed that color defects were suppressed.
(1a) Having an anodic EC material having a redox potential more positive than that of the redox substance of the carrier 33 (the redox substance of the redox substance of the carrier 33 is more oxidized than the redox substance of the anodic EC material). It is easy to be done.).
(1b) Having a cathodic EC material having a negative redox potential than the redox substance of the carrier 33 (the oxidant of the redox substance of the carrier 33 is more reduced than the oxidant of the cathodic EC material. It is easy to be done.).
(1c) By arranging the carrier 33 in at least a part around the first electrode 31 or the second electrode 32, decolorization defects are uniformly reduced.
(1d) In the initial state, the redox state of the redox substance possessed by the carrier 33 is a state in which an oxidant and a reduced substance are mixed.

[Example 2]
(Manufacturing of element)
The EC element 30b shown in FIG. 8 was manufactured by the following steps.

(1) Preparation of Transparent Conductive Glass First, two transparent conductive glasses on which a tin-doped indium oxide (ITO) film was formed were prepared.

(2) Preparation of Substrate Next, using a commercially available ITO etching solution, the ITO film outside the position of α in FIG. 8A was partially removed. The ITO film remaining by this operation was used as the first electrode 31 or the second electrode 32.

(3) Preparation of first electrode (porous electrode) 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 are mixed, stirred at 80 ° C. for 8 hours, and then vacuumed. After drying for 1 day, a cake of tin oxide nanoparticles was obtained. 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 was applied and formed on the ITO film 31a provided in the formation region of the first electrode 31, and then calcined at 350 ° C. for 60 minutes to obtain an antimony-doped tin oxide nanoparticle film (). Hereinafter, it may be referred to as “nanoparticle film”). A 5 mM ethanol solution of 1,1'-ferrocene dicarboxylic acid, which is an anodic redox substance (non-EC), was applied to the nanoparticle film and allowed to stand overnight. Next, the nanoparticle film was washed with ethanol and dried to prepare the first electrode 31.

(4) Preparation of Carrier A commercially available titanium oxide nanopaste was applied to the region of the substrate 8 having the second electrode 2 from which the ITO film had been removed in the same manner as in Example 1 (3), and the temperature was 350 ° C. for 60 minutes. A porous titanium oxide particle film was formed by firing under the conditions. Since the titanium oxide particle film is not electrically connected to the external circuit, it functions not as an electrode but as a carrier 33. Next, a 1 mM aqueous solution of compound 2, which is a cathodic redox substance (EC property), was applied to the titanium oxide particle film and allowed to stand overnight. Next, the carrier 33 was prepared by washing and drying the titanium oxide particle film.

(Evaluation of ease of oxidation / reduction)
Which of the redox substance (Compound 2) immobilized on the carrier 33 and the cathodic EC material (ethyl viologen) 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 ethyl viologen to bring the ethyl viologen into a reduced state (blue). Next, a solution having a reduced ethyl viologen was added dropwise onto the carrier 33 on which the redox substance (Compound 2) was immobilized under a nitrogen atmosphere. Then, the blue color derived from ethyl viologen disappeared, and the carrier 33 changed to light yellowish green instead. The change of the carrier 33 to light yellowish green in this way means that the compound 2 has been reduced.

As a result, electron transfer from the reduced form of ethyl viologen (cathodic EC material) to the oxidized form of compound 2 (oxidation-reducing substance (EC-based compound)) was confirmed. Therefore, this cathodic EC material is a carrier 33. It was confirmed that it is more easily oxidized than the redox substance possessed by. On the other hand, even when a 5 mM ethanol solution of ferrocene dicarboxylic acid was dropped onto the carrier 33 on which the compound 2 was immobilized, the carrier 33 was not colored light yellowish green. From the above, it was found that the redox substance of the carrier 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 (substrate 37) on which the carrier 33 is formed, leaving the injection port 40 on the outer periphery. Was applied to. Further, the same adhesive containing no beads was applied between the first electrode 31 or the second electrode 32 and the carrier 33 so as to have a height of 40 μm to form a partition wall 36. After that, two transparent conductive glasses were laminated so that the electrode extraction portion 39 was exposed so that the first electrode 31 and the second electrode 32 faced each other and the carriers 33 faced each other. .. Next, the adhesive was cured by irradiating the carrier 33 with UV light in a masked state so as not to expose the carrier 33 to UV light. As a result, the substrate 37 and the substrate 38 were adhered to each other.

(5) Injection of Electrolyte Solution An electrolyte solution was prepared by dissolving ethylviologen hexafluorophosphate, which is a cathodic EC material, in a propylene carbonate (PC) solution of 0.1 M tetrabutylammonium hexafluorophosphate. At this time, the concentration of ethyl viologen hexafluorophosphate contained in the electrolyte solution was 20 mM. Next, after injecting this electrolyte solution (electrolyte 34) from the injection port 40, the EC element 30b 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. Specifically, an EC consisting of an application of a voltage of 1.8 V between the first electrode 31 and the second electrode 32 and a short circuit between the first electrode 31 and the second electrode 32. The element was driven repeatedly. During this repeated driving, the voltage application (driving time for coloring state) was set to 5 seconds, and the short circuit (driving time for decolorizing state) was set to 600 seconds.

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 was arranged so that the optical path of the transmitted light transmitted through the first electrode 31 and the second electrode 32 and the carrier 33 was deviated from the optical path.

[Comparative Example 2]
In Example 2, the EC element was manufactured by the same method as in Example 2 except that the step (2) was omitted and the carrier was omitted in the step (4). In this comparative example, a porous film corresponding to the first electrode 31 in FIG. 8 is formed on the ITO 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 applying a voltage between both electrodes (31, 32) and short-circuiting between both electrodes (31, 32) is repeated, the EC element of Comparative Example 2 having no carrier has poor decolorization. There has occurred. Specifically, from a short period of time to a long period of time, poor decolorization 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 device of Example 2 provided with the carrier 33 having the redox substance, no decolorization failure due to charge imbalance was observed, and the charge was effectively rebalanced. It was confirmed that. In the EC element of Example 2, the carrier 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 carrier 33 having the redox substance.

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

[Example 3]
(Manufacturing of element)
The EC element 30c shown in FIG. 9 was manufactured by the following steps.

(1) Preparation of Transparent Conductive Glass First, two transparent conductive glasses on which a tin-doped indium oxide (ITO) film was formed were prepared.

(2) Preparation of Substrate Next, using a commercially available ITO etching solution, the ITO film outside the position of α in FIG. 9A was partially removed. The ITO film remaining by this operation was used as the first electrode 31 or the second electrode 32.

(3) Preparation of Carrier By the same method as in Example 1, a titanium oxide particle film was formed on the region of the substrate (37, 38) from which the ITO film had been removed. Next, 1,1'-ferrocene dicarboxylic acid (Fc (COOH) ₂ ) was applied to the titanium oxide particle film of the first transparent conductive glass (base 37) by the same method as in Example 1 (3). Was fixed. Next, the compound 2 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 carrier on which the redox substance was immobilized, specifically, a carrier 33a contained in the substrate 37 and a carrier 33b contained in the substrate 38 were produced.

(4) Adhesion of Substrate A UV-curable adhesive (TB3035B) in which 100 μm spacer beads are mixed as a sealing material 35 with two transparent conductive glasses (substrates 37, 38) on which carriers (33a, 33b) are formed. , Made by ThreeBond Co., Ltd.) was applied to the outer periphery of the port leaving the injection port 40. Further, the partition wall 36 was formed by the same method as in Example 1 (4). 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 carriers (33a, 33b) face each other. Was superposed. Next, the adhesive was cured by irradiating the carriers (33a, 33b) 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). An electrolyte solution was prepared by dissolving the salt. 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 ethyl viologen 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. Specifically, it consists of an application of a voltage of 1.62 V between the first electrode 31 (anode) and the second electrode 32, and a short circuit between the first electrode and the second electrode. The EC element was repeatedly driven. During this repeated driving, the voltage application (driving time for coloring state) was set to 5 seconds, and the short circuit (driving time for decolorizing state) was set to 600 seconds.

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 30c is arranged so that the optical path of the transmitted light passes through the first electrode 31 and the second electrode 32, and the carrier 33 deviates 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 ITO 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)
The results of endurance driving of EC elements for Example 3 and Comparative Example 3 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 carrier has Comparative Example 1. The same decolorization defect as the above occurred.

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

From the above, in the EC device having the anodic EC material and the cathodic EC material, the charge imbalance can be effectively adjusted by the carriers (33a, 33b) included in the EC element 30 by satisfying the following conditions. It was confirmed that the decolorization failure was suppressed.
(3a) The redox substance of the carrier (33a, 33b) is more easily oxidized than the redox substance of the anodic EC material (the redox substance of the carrier (33a, 33b) is anodic. Have a more negative redox potential than EC materials).
(3b) The redox substance of the carrier (33a, 33b) is more easily reduced than the redox of the cathodic EC material (the redox substance of the carrier (33a, 33b) is cathodic. Have a more positive redox potential than EC materials).
(3c) Discoloration defects are uniformly reduced by arranging the carriers (33a, 33b) in at least a part around the first electrode 31 or the second electrode 32.
(3d) The carrier (33a, 33b) has a plurality of redox substances.

1: First electrode, 2: Second electrode, 3: Carrier, 4: Electrolyte, 5: Sealing material, 6: Partition wall, 7 (8): Substrate, 10: EC element

Claims (19)

It has a first electrode, a second electrode, and a carrier, and at least one of the first electrode and the second electrode is transparent, and the first electrode and the second electrode are transparent. An electrochromic element having an electrolyte, an anodic organic electrochromic compound, and a cathodic redox substance between the electrodes.
The electrolyte, the anodic organic electrochromic compound, and the cathodic redox substance are mixed.
The electrolyte is in contact with the first electrode, the second electrode and the carrier.
The carrier further comprises a redox substance and
An electrochromic element characterized in that a reduced product of a redox substance contained in the carrier is more easily oxidized than a reduced product of the anodic organic electrochromic compound. It has a first electrode, a second electrode, and a carrier, and at least one of the first electrode and the second electrode is transparent, and the first electrode and the second electrode are transparent. An electrochromic element having an electrolyte, a cathodic organic electrochromic compound, and an anodic redox substance between the electrodes.
The electrolyte, the cathodic organic electrochromic compound, and the anodic redox substance are mixed.
The electrolyte is in contact with the first electrode, the second electrode and the carrier.
The carrier further comprises a redox substance and
An electrochromic device characterized in that an oxidant of a redox substance contained in the carrier is more easily reduced than an oxidant of the cathodic organic electrochromic compound. It has a first electrode, a second electrode, and a carrier, and at least one of the first electrode and the second electrode is transparent, and the first electrode and the second electrode are transparent. An electrochromic element having an electrolyte, an anodic organic electrochromic material, and a cathodic organic electrochromic compound between the electrodes.
The electrolyte, the anodic organic electrochromic compound, and the cathodic organic electrochromic compound are mixed.
The electrolyte is in contact with the first electrode, the second electrode and the carrier.
The carrier has a redox substance and
The reduced form of the redox substance contained in the carrier is more easily oxidized than the reduced form of the anodic organic electrochromic compound.
An electrochromic device characterized in that an oxidant of a redox substance contained in the carrier is more easily reduced than an oxidant of the cathodic organic electrochromic compound. 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 contained in the carrier. , The electrochromic element according to claim 1 or 3.
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 contained in the carrier. , The electrochromic element according to claim 2 or 3.
E _RO > E _EC (C) (II) Redox potential E _EC (A) of the anode organic electrochromic compounds of the redox potential E _EC of cathodic organic electrochromic compound of component (C), redox potential E redox substance the carrier has _The electrochromic element according to claim 3, wherein the following formula (III) is satisfied between the _RO and the _RO .
E _EC (C) <E _RO <E _EC (A) (III) The electro according to any one of claims 1, 3, 4 and 6, wherein the redox substance of the carrier reduces the oxidant of the anodic organic electrochromic compound. Chromic element. The electro according to any one of claims 2, 3, 5 and 6, wherein the redox substance of the carrier oxidizes the reduced product of the cathodic organic electrochromic compound. Chromic element. The electrochromic device according to any one of claims 1 to 8, wherein the mixture is dissolved. The electro according to any one of claims 1 to 9, wherein the carrier is arranged outside the optical path of light transmitted through at least one of the first electrode and the second electrode. Chromic element. The electrochromic device according to any one of claims 1 to 10, wherein the redox substance contained in the carrier is an electrochromic compound. The electrochromic device according to any one of claims 1 to 11, wherein the carrier is arranged in at least a part around the first electrode or the second electrode. The electrochromic element according to any one of claims 1 to 12, wherein the redox state of the redox substance contained in the carrier is a state in which an oxidant and a reduced substance are mixed. The electrochromic device according to any one of claims 1 to 13, wherein the carrier has two or more kinds of redox substances. The electrochromic device according to any one of claims 1 to 14.
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 15. An imaging optical system with multiple lenses and
The optical filter according to claim 15,
An image pickup apparatus comprising: an image pickup element that receives light transmitted through the optical filter. The imaging device according to claim 17, wherein the imaging optical system is removable. A pair of transparent boards and
The electrochromic element according to any one of claims 1 to 14, which is arranged between the pair of transparent substrates.
A window material comprising an active element connected to the electrochromic element.

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