JP2021076624A - Electrochromic element, optical filter using the same, lens unit, image capturing device, and window material - Google Patents

Abstract

To provide a complementary EC element which exhibits high color uniformity even when concentration of an EC compound is high.SOLUTION: A ratio of an effective diffusion coefficient of an anodic electrochromic compound to that of a cathodic electrochromic compound in an electrochromic layer is set to meet given conditions depending on whether a sealing seal is an anode-priority sealing seal or cathode-priority sealing seal.SELECTED DRAWING: None

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.

A compound whose optical properties (absorption wavelength, absorbance, etc.) of a substance are changed by an electrochemical redox reaction is called an electrochromic (EC) compound. EC elements using EC compounds are applied to display devices, variable reflectance mirrors, variable transmission windows, and the like. EC compounds are classified into two types, inorganic compounds and organic compounds. Of these, organic EC compounds can be designed and changed with a relatively high degree of freedom in absorption wavelength, and have high decolorization and decolorization. It has the feature that contrast can be realized.
In a typical EC element having an organic EC compound, an EC layer containing the EC compound is arranged between a pair of electrodes. In addition, a sealing seal is arranged so as to surround the outer periphery of the EC layer, and plays a role of holding the EC layer and preventing intrusion of substances that cause deterioration of the EC layer. As one kind of a typical EC element having this organic EC compound, there is a complementary type EC element. In this complementary EC element, an anodic EC compound colored by oxidation and a cathodic EC compound colored by reduction are used as EC compounds. In the complementary EC element, by applying a voltage between a pair of electrodes, the oxidation reaction of the anodic EC compound proceeds at the anode to form a colored product, and at the same time, the reduction reaction of the cathode EC compound proceeds at the opposite cathode. Then, a colored body is generated and an electric current flows. Therefore, basically, the amounts of the anodic EC compound colored body and the cathodic EC compound colored body are equal in the entire element.
Responsiveness at the time of coloring / bleaching is one of the important issues of the EC element, and various methods for improving the responsiveness of the EC element are known. For example, Patent Document 1 discloses an EC device in which an electrochemically active substance having a high diffusion coefficient is added to improve the responsiveness at the time of coloring / bleaching. As a method for further improving the responsiveness, it is effective to shorten the distance between the electrodes of the device and increase the concentration of the EC compound in the EC layer. When the distance between the electrodes is shortened, it is necessary to increase the concentration of the EC compound in order to obtain the same optical density as when the distance between the electrodes is long. That is, in order to realize the above method, it is required to increase the concentration of the EC compound.

Japanese Patent No. 4843081

When the present inventor examined an EC element in which the concentration of the EC compound was increased in order to improve the responsiveness of the EC element, the EC layer was colored between the region near the sealing seal and the other regions. It has been found that there is a difference in the color of time and the color in the EC element becomes non-uniform. When non-uniformity (color unevenness) occurs in the color inside the EC element in this way, the color tone of the light passing through the EC element changes non-uniformly, which is a problem.
An object of the present invention is to provide an EC element that exhibits high color uniformity even under conditions where the concentration of the EC compound is high.

The first of the present invention is a sealing seal arranged between the first electrode, the second electrode, the first electrode and the second electrode, and the first electrode and the above. It has a second electrode and an electrochromic layer arranged in a space partitioned by the sealing seal.
The electrochromic layer is an electrochromic device having an anodic electrochromic compound and a cathodic electrochromic compound.
The sealing seal is an anode-priority sealing seal in which the oxidation reaction of the anodic electrochromic compound is prioritized in the vicinity of the sealing seal.
The electrochromic the effective diffusion coefficient D _A of the anodic electrochromic compound in electrochromic layer ', the electrochromic the effective diffusion coefficient D _C of the cathodic electrochromic compounds in electrochromic layer', and when, the following equation (I) It is characterized by satisfying.
_{0.8 ≦ D A '/ D C} '<1 (I)
[D _A ': the electrochromic anodic electrochromic compound total value across all the anodic electrochromic compound contained the product in the electrochromic layer of the individual concentrations and the diffusion coefficient of the anodic electrochromic compound in electrochromic layer The value obtained by dividing by the sum of the concentrations of.
D _C ': the cathodic electrochromic compound total value of over all cathodic electrochromic compound contained the product in the electrochromic layer of the individual concentrations and the diffusion coefficient of the cathodic electrochromic compounds in the electrochromic layer The value obtained by dividing by the total concentration. ]
The second aspect of the present invention is the first electrode, the second electrode, the sealing seal arranged between the first electrode and the second electrode, the first electrode and the second electrode. It has a second electrode and an electrochromic layer arranged in a space partitioned by the sealing seal.
The electrochromic layer is an electrochromic device having an anodic electrochromic compound and a cathodic electrochromic compound.
The sealing seal is a cathode-priority sealing seal in which the reduction reaction of the cathodic electrochromic compound is prioritized in the vicinity of the sealing seal.
The electrochromic the effective diffusion coefficient D _C of the cathodic electrochromic compounds in electrochromic layer ', the electrochromic the effective diffusion coefficient D _A of the anodic electrochromic compound in electrochromic layer', and when, the following equation (III) It is characterized by satisfying.
_{0.8 ≦ D C '/ D A} '<1 (III)
[D _C ': cathodic electrochromic compound total value of over all cathodic electrochromic compound contained the product in the electrochromic layer of the individual concentrations and the diffusion coefficient of the cathodic electrochromic compounds in the electrochromic layer The value obtained by dividing by the sum of the concentrations of.
D _A ': the electrochromic anodic electrochromic compound total value across all the anodic electrochromic compound contained the product in the electrochromic layer of the individual concentrations and the diffusion coefficient of the anodic electrochromic compound in electrochromic layer The value obtained by dividing by the total concentration. ]

According to the present invention, it is possible to provide an EC element that suppresses color unevenness caused by a sealing seal, which is expressed under a condition where the concentration of the EC compound is high.

It is sectional drawing which shows typically the structure of the EC element of one Embodiment of this invention. It is a figure which shows the typical distribution in the EC element plane of color unevenness due to a sealing seal. It is a flowchart for determining the type of a sealing seal. It is a figure explaining the method of defining the central part of an EC element. It is a figure which shows an example of the molar extinction coefficient of a coloring spectrum and an EC compound, and an example of the spectral shape difference of two coloring spectra which have different ratios of a colored body of an anodic EC compound and a cathodic EC compound. It is a figure which shows the relationship between the EC compound concentration and the degree of color unevenness due to a sealing seal. It is a figure which shows typically the appearance mechanism of color unevenness caused by a sealing seal. It is a figure explaining the measuring apparatus of color unevenness, and the evaluation method. It is a figure which shows typically an example of the image pickup apparatus and a lens unit of this invention. It is a figure which shows typically an example of the window material of this invention. It is a graph showing a relationship of the effective diffusion coefficient ratio of anodic EC compound and cathodic EC compound _{(D A '/ D C'} ) and the degree of color unevenness.

[EC element (electrochromic element)]
The EC element of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view schematically showing the configuration of an embodiment of the EC element of the present invention. Here, the cross section is a plane orthogonal to the element plane (electrode plane). The EC element 1 is a device that takes in light from the outside and allows the taken-in light to pass through the EC layer 13 to change the intensity of the emitted light in a predetermined wavelength region.

The EC element 1 of the present embodiment has a first electrode 11a and a second electrode 11b. The first electrode 11a and the second electrode 11b may be arranged on the first substrate 10a and the second substrate 10b, respectively. In the EC element of the present invention, the sealing seal 12 is arranged between the first electrode 11a and the second electrode 11b, and is partitioned by the first electrode 11a, the second electrode 11b, and the sealing seal 12. The EC layer (electrochromic layer) 13 is arranged in the space. The EC layer 13 has a solvent, an anodic EC compound (anodic electrochromic compound), and a cathodic EC compound (cathodic electrochromic compound). Hereinafter, the constituent elements of the EC element of the present invention will be described.

<Electrodes 11a, 11b>
In the present invention, it is preferable that either the first electrode 11a or the second electrode 11b is transparent. 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 11a and the second electrode 11b is a transparent electrode, light is efficiently taken in from the outside of the EC element 1 and interacts with the EC compound to cause the optical characteristics of the EC compound. Is reflected in the emitted light. Further, the "light" here means light in the wavelength region targeted by the EC element. For example, if the EC element 1 is used as a filter for an image pickup device in the visible light region, the target is light in the visible light region, and if it is used as a filter for an image pickup device in the infrared region, the target is light in the infrared region. It becomes.

The first electrode 11a and the second electrode 11b may be arranged on the first substrate 10a and the second substrate 10b, respectively. In the present invention, it is preferable that either the first substrate 10a or the second substrate 10b is transparent. Examples of the transparent substrate on which the electrodes 11a and 11b are arranged include glass and a transparent resin. As the glass, optical glass, quartz glass, white plate glass, blue plate glass, borosilicate glass, non-alkali glass, chemically strengthened glass and the like can be used, and in particular, non-alkali glass can be used from the viewpoint of transparency and durability. .. Examples of the transparent resin include polyethylene terephthalate, polyethylene naphthalate, polynorbornene, polysulfone, polyethersulfone, polyetheretherketone, polyphenylene sulfide, polycarbonate, polyimide, polymethylmethacrylate and the like. Examples of the non-transparent substrate on which the electrodes 11a and 11b are arranged include an opaque resin. Examples of the opaque resin include polypropylene, high-density polyethylene, polytetrafluoroethylene, polyacetal, polybutylene terephthalate, and polyamide.

As the transparent electrode, a transparent conductive oxide, a conductive layer such as dispersed carbon nanotubes, or a transparent electrode in which a metal wire is partially arranged on a transparent substrate 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 or ITO is preferable. When the electrode is formed of a transparent conductive oxide, the film thickness is preferably 10 nm or more and 10000 nm or less. In particular, a layer of a transparent conductive oxide having a film thickness of 10 nm or more and 10000 nm or less and being a layer of FTO or ITO is preferable. This makes it possible to achieve both high permeability and chemical stability. The layer of the transparent conductive oxide 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 is not particularly limited, but a wire made of an electrochemically stable metal material such as Ag, Au, Pt, and Ti 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 11a and the second electrode 11b, as the electrode other than the above-mentioned transparent electrode, a preferable one is selected depending on the application of the EC element 1. For example, when the EC element 1 is a transmissive type, it is preferable that both the first electrode 11a and the second electrode 11b are the above-mentioned transparent electrodes. Further, when the electrodes are arranged on the substrate, it is preferable that both the first substrate 10a and the second substrate 10b are transparent. On the other hand, when the EC element 1 is a reflection type, it is preferable that one of the first electrode 11a and the second electrode 11b is the above-mentioned transparent electrode and the other is an electrode that reflects incident light. .. Further, when the electrodes are arranged on the substrate, it is preferable that at least the substrate on which the transparent electrodes are arranged is transparent. 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 also be used as the electrode behind the reflection layer or the scattering layer.

Regardless of the form of the EC element of the present invention, the constituent materials of the first electrode 11a and the second electrode 11b are stably present in the operating environment of the EC element, and an external voltage is applied. A material capable of rapidly advancing the redox reaction according to the above is preferably used.

As for the arrangement of the first electrode 11a and the second electrode 11b, an arrangement generally known as an electrode arrangement of the EC element can be used. As a typical example, there is an arrangement method in which the first electrode 11a and the second electrode 11b respectively arranged on the substrate face each other and a distance between the electrodes of about 1 μm or more and 500 μm or less is provided. When the distance between the electrodes is long, it is advantageous in that a sufficient amount of EC compound can be arranged to effectively function as an EC element, and that the transmittance at the time of coloring can be reduced. On the other hand, when the distance between the electrodes is short, it is advantageous in that a fast response speed can be achieved.

<EC layer 13>
The EC element of the present invention has an EC layer 13 containing an anodic EC compound and a cathodic EC compound, preferably further containing a solvent, between the first electrode 11a and the second electrode 11b.

[solvent]
The solvent constituting the EC layer 13 is selected according to the application in consideration of the solubility of solutes such as EC compounds, vapor pressure, viscosity, potential window, etc., but is a solvent having polarity. Is preferable. Specific examples thereof include organic polar solvents such as ether compounds, nitrile compounds, alcohol compounds, dimethyl sulfoxide, dimethoxyethane, sulfolane, dimethylformamide, dimethylacetamide, and methylpyrrolidinone, and water. Among them, solvents containing cyclic ethers such as propylene carbonate, ethylene carbonate, γ-butyrolactone, valerolactone, and dioxolane are preferably used from the viewpoints of solubility, boiling point, vapor pressure, viscosity, and potential window of EC compounds, and among them, carbonic acid. Solvents containing propylene are most preferably used.

[EC compound]
In the present invention, the EC compound is a kind of redox substance, and is a substance whose light absorption characteristics change in the light wavelength region targeted by the EC element by the redox reaction. Further, the redox substance is a compound capable of repeatedly causing a redox reaction in a predetermined potential range. The light absorption characteristic referred to here is typically a light absorption state and a light transmission state, and an EC compound is a material that typically switches between a light absorption state and a light transmission state. The EC compound used in the EC device of the present invention is preferably an organic compound. The organic EC compound of the present invention is preferably a low molecular weight organic compound having a molecular weight of 2000 or less.
In the present specification, the EC compound may be referred to as an "anodic EC compound" or a "cathodic EC compound". Each of them will be described in detail below.

(Anodic EC compound)
The anodic EC compound refers to a material whose light absorption characteristics change due to an oxidation reaction in which electrons are usually removed from the EC compound on the anode in the target light wavelength region of the EC element. A typical example is a material that changes from a light transmitting state to a light absorbing state. In this specification, in order to make it easier to imagine the change of the EC compound, the change from the light transmission state to the light absorption state, which is a typical example, may be taken up and described. Further, in the present specification, a molecule in a light transmitting state may be referred to as a "decolorized body", and a molecule in a light absorbing state may be referred to as a "colored body". In that case, in the light wavelength region targeted by the EC element, the reduced product of the anodic EC compound is in a light transmitting state and is expressed as a “decolorizing body”. Further, the oxidant of the anodic EC compound is in a light absorbing state and is expressed as a "colored body".

Examples of anodic EC compounds include thiophene derivatives, amines having an aromatic ring (eg, phenazine derivatives, triallylamine derivatives), pyrrole derivatives, thiadin derivatives, triallylmethane derivatives, bisphenylmethane derivatives, xanthene derivatives, fluoranes. Derivatives and spiropyran derivatives can be mentioned. Among these, as the anodic EC molecule, amines having a low molecular weight aromatic ring are preferable, and a dihydrophenazine derivative is most preferable.

(Cathode EC compound)
The cathodic EC compound refers to a material whose light absorption characteristics change due to a reduction reaction in which electrons are usually donated from an electrode to the EC compound on the cathode in the light wavelength region targeted by the EC element. A typical example is a material that changes from a light transmitting state to a light absorbing state. In the description of the present specification, the reduced product of the cathodic EC compound is in a light absorbing state in the light wavelength region targeted by the EC device, and is expressed as a “colored product”. Further, the oxidant of the cathodic EC compound is in a light transmitting state and is expressed as a "decolorized body".
Examples of the cathodic EC compound include pyridine compounds such as viologen and quinone compounds. Among them, pyridine compounds such as viologen are most preferably used.

[Method of forming EC layer 13]
As a method of introducing a solution containing an EC compound into the EC element 1, for example, when the opposing electrodes 11a and 11b are joined, an opening is formed in the electrodes 11a and 11b or a part of the sealing seal 12. The solution may then be injected through the opening. Specific methods for injecting a solution containing an EC compound into a cell include a vacuum injection method, an atmospheric injection method, a meniscus method, and the like. After injecting the solution containing the EC compound into the cell, the solution can be stably held in the cell by sealing the opening.

<Sealing seal 12>
It is preferable that the first electrode 11a and the second electrode 11b are joined by the sealing seal 12 in an arrangement in which both electrode surfaces face each other. The sealing seal 12 not only maintains the spatial arrangement of the first electrode 11a and the second electrode 11b, but also prevents the EC layer 13 from leaking to the outside of the EC element 1 and protects it from contact with external substances. Carry.

From the above viewpoint, the material constituting the sealing seal 12 is a material that is chemically stable, has low moisture permeability and low gas permeability, and has low solubility in the solvent contained in the EC layer 13. It is preferably configured. For example, an inorganic material such as glass frit, an organic material such as an epoxy-based or acrylic-based resin, a metal, or the like can be used. The sealing seal 12 may have a function of defining the distance between the first electrode 11a and the second electrode 11b by means such as containing a spacer material. If the sealing seal 12 does not have a function of defining the distance between the first electrode 11a and the second electrode 11b, a spacer may be separately arranged to maintain the distance between the two electrodes. .. As the material of the spacer, an inorganic material such as silica beads and glass fiber, and an organic material such as polyimide, polytetrafluoroethylene, polydivinylbenzene, fluororubber, and epoxy resin can be used. In this case, the spacer makes it possible to define and hold the distance between the first electrode 11a and the second electrode 11b constituting the EC element.

The present inventor has found that one of the anodic EC compound and the cathodic EC compound may be colored in the vicinity of the sealing seal 12 of the EC layer 13 in preference to the other. Here, "priority coloring" means that when the EC element 1 is driven and the optical density of the EC element 1 reaches a stable state in which it transitions to the vicinity of the target density, the anodic EC compound and the cathodic EC compound are used. It means that one of the colored bodies is present more than the other colored body. For example, "the anodic EC compound is preferentially colored in the vicinity of the sealing seal 12" means that the anodic property is obtained at the stage where the optical density of the EC element is stable after the EC element is driven in the vicinity of the sealing seal 12. It is shown that the colorant of the EC compound is present in a larger amount than the colorant of the cathodic EC compound. Specifically, it shows that the color of the colorant of the anodic EC compound is expressed more strongly than the color of the colorant of the cathode EC compound. When the anodic EC compound or the cathodic EC compound is preferentially colored in the vicinity of the sealing seal 12, the EC element is driven in the vicinity of the sealing seal 12 and other regions of the EC layer 13. There will be a difference in color at the time, and color unevenness will occur in the element surface.

FIG. 2 shows the distribution of a typical priority coloring region seen in the vicinity of the sealing seal 12. Here, FIG. 2 is a bird's-eye view of the EC element 1 from a direction perpendicular to the element surface. As shown in FIG. 2, the priority coloring region is generated in the region 13a closest to the sealing seal 12. Here, the "sealing seal nearest neighbor 13a" is a region of the EC layer 13 near the boundary where the sealing seal 12 and the EC layer 13 are in contact with each other, and this region is the side of the sealing seal 12 in contact with the EC layer 13. It typically has a width of about 50-1000 μm from the boundary of. Further, depending on the appearance of the priority coloring in the "sealing seal nearest neighbor 13a", the sealing seal 12 may be an anode-priority sealing seal, a cathode-priority sealing seal, or other sealing seals that do not correspond to these two. It is classified into three categories. The following describes two seals, an anode-priority sealing seal and a cathode-priority sealing seal.

[Anode priority sealing seal]
The anode-priority sealing seal is defined as the sealing seal 12 showing preferential coloring of the anodic EC compound in the nearest neighbor 13a of the sealing seal. The characteristics of the sealing material exhibiting the properties as an anode-priority sealing seal include that it is composed of a resin having a relatively large polarity and that it contains an oxidizing compound.
The reason for the former is as follows. While the decolorizer of a viologen compound, which is a typical cathode EC compound, has a positive charge, it is represented by an aromatic amine compound such as triphenylamines and phenazines, and a thiophene compound. As described above, the decolorizer of the anodic EC compound has no charge. Therefore, the decolorizing body of the cathodic EC compound has a larger polarity than the decolorizing body of the anodic EC compound. In the vicinity of the sealing seal 13a, a thin film made of a material constituting the sealing seal 12 is present on the electrode surface. Therefore, in the region of 13a closest to the sealing seal, when the sealing seal 12 is composed of a resin having a large polarity, the interaction between the decolorizing body of the cathodic EC compound having a high polarity and the resin having a large polarity is observed. It is relatively large as a decolorizing body of an anodic EC compound having low polarity. As a result, the movement of the cathodic EC compound to the electrode surface of the decolorizing body is greatly hindered as compared with the decolorizing body of the anodic EC compound. As a result, the anodic EC compound is preferentially colored in the vicinity 13a of the sealing seal. Examples of those satisfying the above-mentioned characteristics include a sealing seal containing an epoxy resin.

The reason for the latter is as follows. When the oxidative compound is contained in the sealing seal 12, protons may be added to the anodic EC compound existing in the vicinity 13a of the sealing seal, or electrons may be taken from the anodic EC compound to cause an oxidizing action. When the oxidized anodic EC compound has absorption in the visible region, the absorption derived from the oxidatively colored species of the anodic EC compound appears strongly in the vicinity 13a of the sealing seal. Examples of those satisfying the above-mentioned characteristics include a curing agent and a curing accelerator for a heat / photocurable epoxy resin and a photocurable acrylic resin, and specifically, an acid anhydride, a phenol resin, and an antimony. Examples thereof include Lewis acid produced as a by-product from an onium salt such as a system compound.

More specific examples of curing agents and curing accelerators that can serve as an anode-priority sealing seal include onium salts such as sulfonium salts, benzothiazolium salts, ammonium salts, and phosphonium salts, and antimonate-based and phosphate-based compounds. Combined potential thermoacid generators, halogen-containing triazine compounds, diazoketone compounds, onium salt compounds, sulfonic acid compounds potential photoacid generators, phenolic resin curing agents such as novolak resin and cresol resin, Acid anhydrides such as phthalic anhydrides, maleic anhydrides, pyromellitic anhydrides, DBU (1,8-diazabicyclo (5,4,0) -undecene-7), DBN (1,5-diazabicyclo (4,3)) , 0) -Nonen-5) and other p-toluene sulfonates and phenol salts and other curing accelerators can be mentioned. The type of the sealing seal 12 is classified according to the method for determining the type of the sealing seal 12, which will be described later, regardless of the presence or absence of the above-mentioned components.

[Cathode priority sealing seal]
The cathodic priority sealing seal is defined as a sealing seal 12 showing preferential coloring of the cathodic EC compound in the vicinity 13a of the sealing seal. The characteristics of the sealing material exhibiting the properties as a cathode-priority sealing seal include that it is composed of a material having a relatively small polarity and that it contains a reducing compound.
The reason for the former is as follows. As described above, in the vicinity of the sealing seal 13a, a thin film made of a material constituting the sealing seal is present on the electrode surface. Therefore, when the sealing seal 12 is made of a material having a small polarity, the interaction between the decolorizing body of the anodic EC compound having a small polarity and the sealing seal 12 having a small polarity occurs in the vicinity 13a of the sealing seal. It is relatively large as a decolorizing body of a highly polar cathodic EC compound. As a result, the movement of the anodic EC compound to the electrode surface is greatly hindered as compared with the decolorizing body of the cathodic EC compound having a large polarity. As a result, the cathodic EC compound is preferentially colored in the vicinity 13a of the sealing seal. Examples of those satisfying the above-mentioned characteristics include a sealing seal having synthetic rubber and the like.

The reason for the latter is as follows. When the reducing compound is contained in the sealing seal 12, the reducing compound present on the outermost surface of the membrane or the eluted reducing compound may cause a reduction reaction of the cathodic EC compound existing in the vicinity of the sealing seal. .. As a result, the coloring of the cathodic EC compound appears strongly in the vicinity 13a of the sealing seal. Examples of those satisfying the above-mentioned characteristics include a sealing seal containing a curing agent such as a low molecular weight amine compound, a polyamide amine, an imidazole compound, and a triarylphosphin compound, and a curing accelerator.

More specific examples of curing agents and curing accelerators that can serve as a cathode-priority sealing seal include carbamates, carbamoyloximes, aromatic sulfonamides, α-lactones, benzhydryl ammonium salts, and imidazole salts. Potential photoamine generators such as amidine salts, potential thermal amine generators such as piperidine carboxylates, aliphatic polyamines such as triethylenetetramine, aromatic polyamines such as diaminodiphenylmethane, low molecular weight amines, and alkylamino. Acceleration of curing of sensitizers such as benzophenone, DBU (1,8-diazabicyclo (5,4,0) -undecene-7), DBN (1,5-diazabicyclo (4,3,0) -nonen-5), etc. Examples include agents. The type of the sealing seal 12 is classified according to the method for determining the type of the sealing seal 12, which will be described later, regardless of the presence or absence of the above-mentioned components.

[Method for determining the type of sealing seal 12]
The sealing seal 12 is classified into the above-mentioned anode-priority sealing seal, cathode-priority sealing seal, and other sealing seals that do not fall under these two. A method for performing these classifications will be described with reference to the flowchart of FIG.

First, a voltage is applied to the EC element 1 to bring it into a colored state, and the coloring of the central portion of the element and the coloring of the sealing seal nearest neighbor 13a are confirmed. Next, the coloring of the central portion of the element is compared with the coloring of the sealing seal nearest neighbor 13a.
The method of defining the central portion of the element will be described with reference to FIG. First, the area inside the sealing seal 12 is defined by a rectangular area 14 having the maximum area. A circular region 15 having a diameter centered on the center of gravity of the rectangular region defined in this way and having a diameter of 1/5 times the short side of the rectangular region is defined as the central portion of the EC element 1.

When confirming the coloring of the region 13a closest to the sealing seal, the coloring of the region in the EC layer 13 within 1 mm from the boundary between the sealing seal 12 and the EC layer 13 is confirmed, and the coloring of the region is confirmed. When the coloring of one of the EC compounds appears stronger than that of the central portion 15 of the element in a part or the entire region, it is determined that there is "priority coloring".

From the above-mentioned specified conditions of the element central portion 15, the coloring of the element central portion 15 is the coloring in the region of the EC layer 13 away from the vicinity of the sealing seal 12, and the EC when there is no color unevenness, that is, preferential coloring. It reflects the coloring of the element 1. Therefore, when the coloring of the anodic EC compound or the cathodic EC compound appears more strongly in the sealing seal nearest vicinity 13a as compared with the element central portion 15, it is determined that the sealing seal nearest vicinity 13a has priority coloring. To. Color comparison can be performed by visual inspection, color spectrum analysis using a spectroscope, image analysis using a camera, etc. Among them, color comparison by color spectrum analysis using a spectroscope is described in detail with reference to FIG. Explain to.

FIG. 5A shows an example of the molar extinction coefficient of the anodic EC compound and the cathodic EC compound at the time of coloring, and the coloring spectrum appearing as a superposition thereof. FIG. 5B shows two coloring spectra in which the ratio of the colored body concentration of the anodic EC compound and the cathode EC compound is different. In FIG. 5B, when the colorant concentration ratio (anode colorant / cathode colorant) is 1, the coloration spectrum 1 is, and when it is 1.25, the colorant spectrum 2 is.
First, the coloring spectrum in the vicinity 13a of the sealing seal is acquired using a spectroscope. Here, according to the Lambert-Beer law, the absorption spectrum A (λ) can be expressed by the following equation (1).

In the above formula, λ indicates a wavelength, Ai (i = 1, 2, ... N) indicates a different anodic EC compound, and Cj (j = 1, 2, ... M) indicates a different cathodic EC compound. .. Further, ε _Ai (λ) is the molar extinction coefficient of the anodic EC compound Ai during coloring, and ε _Cj (λ) is the molar extinction coefficient of the cathodic EC compound Cj during coloring. Further, C ^* _Ai is the concentration of the colored body of the anodic EC compound, C ^* _Cj is the concentration of the colored body of the cathodic EC compound, and L is the distance that the optical axis crosses the EC layer 13.

From the above formula (1), the coloring ratio R _AC of the anodic EC compound and the cathodic EC compound is calculated using the molar extinction coefficient of the EC compound. Here, _RAC is a value defined by the following equation (2).

The same procedure is performed for the central portion 15 of the device, and the coloring ratio R _AC'of the anodic EC compound and the cathodic EC compound is calculated. _{From the relationship between the values of R AC} and R _{AC'calculated in} this way, the presence or absence of preferential coloring and the preferred coloring species (anodic EC compound / cathodic EC compound) are determined.

(Conditions for determining preferential coloring of anodic EC compounds)
When the relationship of the following formula (3) is established, it is determined that "the anodic EC compound is preferentially colored in the nearest neighbor 13a of the sealing seal".
_{R AC> 1.01R AC '(3} )

When the following formula (4) is satisfied in addition to the above formula (3), the coloring of the cathodic EC compound is typical green to blue of the viologen derivative, and the coloring of the anodic EC compound is that of the dihydrophenazine derivative. In the case of a typical red color, in an image of the EC element 1 taken by a camera so that the colored region is properly exposed, the color difference between the nearest 13a of the sealing seal and the central portion 15 of the element is clear. Appears.
R _AC > 1.03R _AC '(4)

When the following formula (5) is satisfied in addition to the above formula (4), the coloring of the cathodic EC compound is typical green to blue of the viologen derivative, and the coloring of the anodic EC compound is that of the dihydrophenazine derivative. In the case of a typical red color, the color difference between the sealing seal nearest vicinity 13a and the element central portion 15 clearly appears even in the direct visual observation of the EC element 1.
_{R AC> 1.10R AC '(5} )

(Conditions for determining preferential coloring of cathodic EC compounds)
When the relationship of the following formula (6) is established, it is determined that "the anodic EC compound is preferentially colored in the nearest neighbor 13a of the sealing seal".
R _AC <0.99R _AC '(6)

When the following formula (7) is satisfied in addition to the above formula (6), the coloring of the cathodic EC compound is typical green to blue of the viologen derivative, and the coloring of the anodic EC compound is that of the dihydrophenazine derivative. In the case of a typical red color, in an image of the EC element 1 taken by a camera so that the colored region is properly exposed, the color difference between the nearest 13a of the sealing seal and the central portion 15 of the element is clear. Appears.
R _AC <0.97R _AC '(7)

When the following formula (8) is satisfied in addition to the above formula (7), the coloring of the cathodic EC compound is typical green to blue of the viologen derivative, and the coloring of the anodic EC compound is that of the dihydrophenazine derivative. In the case of a typical red color, the color difference between the sealing seal nearest vicinity 13a and the element central portion 15 clearly appears even in the direct visual observation of the EC element 1.
R _AC <0.91 _{R CA} '(8)

Therefore, when determining the priority coloring, first, it is confirmed from the photographed image of the EC element 1 by visual inspection or by a camera whether there is a clear color difference between the sealing seal nearest vicinity 13a and the element central portion 15. As a result, when the clear color difference is unclear by these methods, it is better to make a judgment using the coloring spectrum.
As a result of confirming the coloring of the element central portion 15 and the sealing seal nearest neighbor 13a in this way, if there is no priority coloring, the sealing seal 12 is determined to be "another sealing seal". When priority coloring is confirmed, the type of the sealing seal 12 is further determined by the following process.

The polarity of the voltage applied to the EC element 1 is reversed, and the coloring of the sealing seal nearest neighbor 13a is confirmed again. At this time, when the type of the EC compound to be preferentially colored (anodic EC compound / cathodic EC compound) changes, the sealing seal 12 is determined to be "another sealing seal".
When the type of the EC compound to be preferentially colored does not change due to the polarity reversal, it is determined as follows. When the EC compound to be preferentially colored in the vicinity 13a of the sealing seal is an anodic EC compound, the sealing seal is determined to be an "anode-priority sealing seal". Further, when the EC compound to be preferentially colored in the vicinity 13a of the sealing seal is a cathodic EC compound, the sealing seal is determined to be a “cathodic preferential sealing seal”.

The reason for performing this discrimination by polarity reversal will be described below. Even in the case of "other sealing seals" that are neither "anode-priority sealing seals" nor "cathode-priority sealing seals", preferential coloring may occur in the vicinity of the sealing seal 12. A typical example of such a case is a case where one of the electrodes has an obstacle that hinders the movement of the EC compound to the electrode surface. In such a case, coloring of the EC compound according to the polarity of the electrode preferentially occurs on the electrode on the side where no obstacle exists during EC driving. (Such a phenomenon may be described as electrode obstacle color unevenness.) Specifically, in a region where such an obstacle exists at the cathode and no obstacle exists at the anode, the anodic EC compound is colored. Prioritize. Further, in a region where such an obstacle is present on the anode and no obstacle is present on the cathode, coloring of the cathodic EC compound is prioritized. Here, in the nearest neighbor 13a of the sealing seal, one electrode may be covered with a thin film made of a material constituting the sealing seal 12, and a region where the other electrode is not coated may occur. In such a region, electrode obstacle color unevenness appears remarkably.

In the electrode obstacle color unevenness, the EC compound that is preferentially colored changes to the other EC compound by reversing the polarity of the voltage applied from the outside when the EC element 1 is driven. Specifically, by reversing the polarity of the voltage, the preferential coloring of the anodic EC compound changes to the preferential coloring of the cathodic EC compound, and the preferential coloring of the cathodic EC compound changes to the preferential coloring of the anodic EC compound. .. On the other hand, in the case of color unevenness caused by the anode-priority sealing seal and the cathode-priority sealing seal, the type of EC compound to be preferentially colored does not change with respect to the polarity reversal of the voltage. It can be distinguished from the color unevenness that occurs in.

[Relationship between EC compound concentration and color unevenness caused by sealing seal 12]
FIG. 6 shows the relationship between the concentration of the EC compound and the degree of color unevenness caused by the sealing seal 12. The EC compound concentration on the horizontal axis of FIG. 6 is the sum of the concentration of the anodic EC compound and the concentration of the cathodic EC compound contained in the EC layer 13. In the acquisition of the data shown in FIG. 6, the effective diffusion coefficient ratio of anodic EC compound and cathodic EC compounds to be described later _{(D A '/ D C'} ) is unified to 1, and the anode of EC compound And the concentration of the cathodic EC compound are equal. The degree of color unevenness (ΔE ₀₀ ) on the vertical axis of FIG. 6 will be described later. From this, in the concentration region where the concentration of the EC compound is 0.1 mol / L or more, the degree of color unevenness due to the sealing seal 12 becomes large, and further in the concentration region where the concentration of the EC compound is 0.3 mol / L or more. It can be seen that the degree of color unevenness increases. An object of the present invention is to reduce the degree of color unevenness caused by the sealing seal 12, and the effect of the present invention is strongly exhibited in a concentration region of 0.1 mol / L or more, particularly 0.3 mol / L or more. It will be.

[Mechanism of color unevenness caused by sealing seal 12]
The present inventor observed and analyzed the surfaces of the electrodes 11a and 11b in the vicinity of the sealing seal 12 in order to identify the cause of preferential coloring in the vicinity 13a of the sealing seal when the EC element 1 was driven. .. As a result, it was clarified that a thin film composed of the components constituting the sealing seal 12 was formed on the surfaces of the electrodes 11a and 11b in the vicinity of the sealing seal 12. In addition, electrochemical measurements were performed on the anode-priority sealing seal. Specifically, electrodes 11a and 11b formed by forming thin films composed of the components constituting the sealing seal 12 with various thicknesses are produced, and the coloring reactivity of the anodic EC compound and the cathodic EC compound on the surface of the thin film is colored. It was examined from the current at the time of reaction. As a result, the following became clear.
(1) On the electrode in which the thin film exists, the coloring reaction rate of the cathodic EC compound and the anodic EC compound decreases as compared with the electrode in which the thin film does not exist, and the degree thereof increases as the film thickness increases.
(2) As the film thickness of the thin film increases, the coloring reaction rate of any of the thin films decreases significantly, and the magnitude relationship of the coloring reaction rate is that anodic EC compound> cathodic EC compound.

The above two points are experimental facts regarding the anode-priority sealing seal. Further, in the cathode-priority sealing seal, (1) is the same, but the magnitude relationship between the anode-priority sealing seal and the coloring reaction rate is reversed with respect to (2). That is, as the film thickness of the thin film increases, the magnitude relationship of the coloring reaction rate becomes that the cathodic EC compound> the anodic EC compound.

FIG. 7 is a diagram schematically showing the expression mechanism of color unevenness derived from these experimental facts. FIG. 7 shows the vicinity of the sealing seal 12 in the cross-sectional view of the EC element 1. Here, the cross section is a plane orthogonal to the element plane. FIG. 7 (a) shows the mechanism of color unevenness when the sealing seal 12 is the anode-priority sealing seal, and FIG. 7 (b) shows the case where the sealing seal 12 is the cathode-priority sealing seal. This is the mechanism of color unevenness.

In FIG. 7, the first electrode 11a is an anode electrode and the second electrode 11b is a cathode electrode. The black "A" (A in the white circle) indicates the decolorizing body of the anodic EC compound, and the white "A" (A in the black circle) indicates the colored body of the anodic EC compound. Further, the black “C” (C in the white circle) indicates the decolorizing body of the cathodic EC compound, and the white “C” (C in the black circle) indicates the colored body of the cathodic EC compound.

As shown in FIG. 7A, when the sealing seal 12 is an anode-priority sealing seal, the thin film (sealing seal 12) on the electrode has a relatively large thickness in the vicinity 13a of the sealing seal. From the fact of (2) above, the coloring amount of the anodic EC compound per unit time is larger than the coloring amount of the cathodic EC compound per unit time. As a result, preferential coloring of the anodic EC compound can be seen.

Further, when the sealing seal 12 is a cathode-priority sealing seal, the unit time of the cathode EC compound is in the vicinity 13a of the sealing seal where the film thickness of the thin film (sealing seal 12) on the electrode is relatively large. The amount of coloring per unit time is larger than the amount of coloring per unit time of the anodic EC compound. As a result, preferential coloring of the anodic EC compound can be seen.

[Solution for Color Unevenness Caused by Seal 12]
In an EC device, the reaction rate is generally determined by two processes, an "electron transfer process" and a "material transport process". The present inventor attempted to control the reaction rate by using the "substance transport process" among them. Assuming that a sufficient overvoltage is applied to the EC element so that the "electron transfer process" does not determine the reaction rate and a steady current flows, the reaction amount (∝ current i) per unit time is calculated from Fick's first law by the following equation. It is described as (9).
i∝D (dc / dx) (9)

In the above formula (9), D is the diffusion coefficient of the substance. Further, x is a direction perpendicular to the electrode surface (thickness direction of the element), and dc / dx is a density gradient of the EC compound decolorizer in the thickness direction of the device. Here, the concentration gradient depends on the EC compound concentration and the distance between the electrodes of the EC element, and if the distance between the electrodes is determined by the EC element configuration and is fixed, the concentration gradient is substantially proportional to the EC compound concentration. You can think of it as. Therefore, the above formula (9) is more simply described as the following formula (10) using the bulk concentration (that is, the initial concentration before the start of the reaction) c of the EC compound.
i∝D ・ c (10)

From the formula (10), it can be seen that the reaction rate can be controlled by the diffusion coefficient of the EC compound. Therefore, by adjusting the ratio of the diffusion coefficients of the anodic EC compound and the cathodic EC compound, the ratio of the reaction rates of both can be controlled, and the preferential coloring that occurs in the vicinity of the sealing seal 12 can be reduced. .. Diffusion coefficient where anodic EC compounds, in consideration of the fact that the EC compound of anode species may be more, defined by the following equation (11) effective diffusion coefficient D _A 'shown in.

In the above formula (11), A _i represents different anodic EC compounds depending on the subscript number. The c _Ai is the concentration of the anodic EC compound Ai, the D _Ai shows the diffusion coefficient of the anodic EC compound A _i. n is the number of anode species, when the anodic EC compound in EC layer 13 is included n _{species, A 1, A 2, ...} , A n correspond to the respective anodic EC compound. The reason for defining the effective diffusion coefficient of the anodic EC compound as shown in the equation (11) is as follows.

The magnitude of the reaction current of each anodic EC compound corresponds to the product of the concentration of each anodic EC compound and the diffusion coefficient from the formula (10). Therefore, the product of the concentration of each anodic EC compound and the diffusion coefficient added over all the anodic species corresponds to the magnitude of the reaction current of the anodic species as a whole, and this is divided by the total concentration of the anodic EC compounds. By doing so, an amount corresponding to the diffusion coefficient of the anode species as a whole can be obtained.

Similarly, the diffusion coefficient of the cathodic EC compound is defined by the effective diffusion coefficient D _C 'shown in the following equation (12).

In the above formula (12), C _i denotes each different cathodic EC compound number suffixes. Further, c _Ci indicates the concentration of the cathodic EC compound C _i , and D _Ci indicates the diffusion coefficient of the cathodic EC compound C _i. m is the number of cathodic species, and when m kinds of cathodic EC compounds are contained in the EC layer 13, C ₁ , C ₂ , ..., C _m correspond to the respective cathodic EC compounds.

Effective diffusion coefficient D _A of anodic EC compound defined as described above 'and the effective diffusion coefficient D _C of cathodic EC compounds' ratio of (D _A '/ D _C') by variously changing an anode The degree of color unevenness due to the preferential sealing was measured. As a result, when the D _A '/ D _C' satisfies the following formula (I), that color unevenness is remarkably suppressed revealed.
_{0.8 ≦ D A '/ D C} '<1 (I)

Furthermore, it was confirmed that color unevenness was suppressed to a higher degree when the following formula (II) was satisfied in addition to the condition of the above formula (I).
_{0.951 ≦ D A '/ D C} '<1 (II)

That is, the range of significant inhibition is observed D _A '/ D _C' of color unevenness exists an upper limit and a lower limit. The reason why there is an upper limit is as follows. In the anode-priority sealing seal, the reaction rate of the anodic EC compound is higher than the reaction rate of the cathodic EC compound in the vicinity of the sealing seal 12, and as a result, preferential coloring of the anodic EC compound occurs. Thus, 'a D _C' D _A smaller than, that D _A '/ D _C' a is made smaller than 1, to suppress the difference in the reaction rate of the anodic EC compound and cathodic EC compounds, preferentially colored It is possible to reduce the degree of.

The reason why the lower limit exists is as follows. The reaction rate ratio of cathodic EC compound and anodic EC compounds, large ratio of the effective diffusion coefficient of the effective diffusion coefficient and the cathodic EC compound of anodic EC compound _{(D A '/ D C'} ) than it Consider the case. In this case, the compensation of the reaction rate of the cathodic EC compound by the diffusion coefficient becomes excessive, and when the sealing seal 12 is the anode-priority sealing seal, the cathode EC compound is preferentially colored in the nearest vicinity 13a. Will occur instead. This D _A '/ D _C' from that should at least reaction rate ratio of cathodic EC compound and anodic EC compound in closest 13a is requested.

The present inventor conducted the following experiment in order to estimate the reaction rate ratio of the cathodic EC compound and the anodic EC compound in the vicinity 13a of the sealing seal. Equal concentrations of anodic EC compound and cathodic EC compound, further adjust the EC solution in _{D A '/ D C' =} 1 in relation to prepare an EC element. After applying a voltage to the EC element and stabilizing the colored state, a colored spectrum was acquired for the nearest neighbor 13a of the anode-priority sealing seal. The magnitudes of the colored spectral components of the anodic EC compound and the colored spectral components of the cathodic EC compound contained in the spectrum were estimated using the known molar absorption coefficients of each EC compound. As a result, it was clarified that the amount of the colored body of the cathodic EC compound calculated from the spectrum was about 0.8 times that of the colored body of the anodic EC compound in the region. The amount of the colored substance obtained here is an integral value of the amount of the colored substance produced in a unit time, and the ratio of the reaction rates of the cathodic EC compound and the anodic EC compound in the vicinity of the sealing seal is obtained from the above experiment. Equal to the ratio of colored compounds. From the above, D _A '/ D _C' is determined that should be 0.8 or more.

When the sealing seal 12 is a cathode-priority sealing seal, the diffusion coefficient of the anodic EC compound is set to the diffusion coefficient of the cathode EC compound, and the cathodic EC is used for the above-mentioned solution of the anode-priority sealing seal. An effective solution can be obtained by replacing the diffusion coefficient of the compound with the diffusion coefficient of the anodic EC compound. That is, when you the ratio of the effective diffusion coefficient of the effective diffusion coefficient and anodic EC compound of cathodic EC compound _{(D C '/ D A'} ) saw the following formula (I), the color unevenness can be significantly suppressed To.
_{0.8 ≦ D C '/ D A} '<1 (III)

Further, when the following formula (IV) is satisfied in addition to the condition of the formula (III), the color unevenness is suppressed to a higher degree.
_{0.951 ≦ D C '/ D A} '<1 (IV)

Specific methods for adjusting the effective diffusion coefficient ratio between the anodic EC compound and the cathodic EC compound described above include the following methods in addition to changing the material type of the EC compound. An EC compound having a relatively small diffusion coefficient and an EC compound having a relatively large diffusion coefficient are used for either the anode type, the cathode type, or both. At this time, from the definitions of the formulas (11) and (12), it is possible to change the effective diffusion coefficient ratio by changing the concentration ratio without changing the total concentration of these EC compounds. Specifically, the effective diffusion coefficient can be increased by increasing the concentration ratio of the EC compound having a relatively large diffusion coefficient. Further, the effective diffusion coefficient can be reduced by increasing the concentration ratio of the EC compound having a relatively small diffusion coefficient. At this time, it is preferable that the coloring spectra of these EC compounds are highly similar to each other. The reason for this is that the degree to which the mixed spectral shape of these EC compounds changes due to the change in the concentration ratio can be suppressed by increasing the similarity of the coloring spectra of the EC compounds.

In the region other than the sealing seal closest 13a, even in the case of changing the value of the ratio of the effective diffusion coefficient of the anodic EC compound and cathodic EC compound _{(D A '/ D C'} ), on coloration There is no change in color. As described above, both the anode and cathode electrodes are electrically connected when the EC element is driven. Therefore, the amount of reaction charge at the anode and the amount of reaction charge at the cathode are equal in the region where there is no element that inhibits the coloring reaction on the electrode surface. Therefore, in a region other than the sealing seal closest 13a, in the case of changing the value of D _A '/ D _C' also, the amount of coloring of anodic EC compound and cathodic EC compound during EC element drive The relationship is 1: 1 and the color at the time of coloring is constant.

[Method of measuring the diffusion coefficient of EC compounds]
The diffusion coefficient of electrochromic molecules can be measured by known electrochemical methods. As an example of the measurement method, the measurement by the potential step method can be mentioned. The measurement method of the diffusion coefficient by chronoamperometry is described below as a measurement example of the positive step method.

<Measurement method of diffusion coefficient by chronoamperometry>
An EC compound of about 1 mM is dissolved in a solution containing a supporting salt (for example, a solution of 0.2 M tetrabutylammonium hexafluorophosphate in propylene carbonate) and bubbling with an inert gas to remove dissolved oxygen. The above solution is introduced into a tripolar cell using a working electrode (eg, a glassy carbon electrode), a counter electrode (eg, a platinum electrode), and a reference electrode (eg, Ag / Ag + electrode). A potential sufficient to generate a colored body of the EC compound, which has been determined in advance by a cyclic voltanmogram or the like, is applied to the working electrode, and the flowing current is measured for about several tens of seconds. It is generally known that the time response i (t) of the flowing current follows the following Cottlell equation. Therefore, it is possible to plot the measured transient current against the reciprocal of the square root of the elapsed time and calculate the diffusion coefficient from the slope.

ｎ：一分子反応時に関わる電子数
Ｆ：ファラデー定数
ｃ：ＥＣ素子のバルク濃度（即ち、溶液の初期濃度
Ａ：電極面積
Ｄ：ＥＣ化合物の拡散係数
ｔ：時間

n: Number of electrons involved in single molecule reaction F: Faraday constant c: Bulk concentration of EC element (that is, initial concentration of solution A: Electrode area D: Diffusion coefficient of EC compound t: Time

[Evaluation method of color unevenness]
A method for evaluating color unevenness, which is color non-uniformity in the EC element, will be described with reference to FIG. FIG. 8A shows the components of the evaluation system and their arrangement. FIG. 8B is a diagram schematically showing the relationship between the acquired image obtained thereby and the analysis area.

The surface illumination 21 and the image pickup device 22 are arranged so that the optical axis of the transmissive EC element 1 is perpendicular to the element surface. Images are acquired over time for 24 hours immediately after the EC element 1 is driven. In the acquired image 23, the effective optical region in the region surrounded by the sealing seal 12 is defined as the analysis region 24 for which the analysis described later is performed. Here, the effective optical region is an region in the EC element 1 of the optical device in which the change in the transmittance of the EC element 1 functions to fulfill the function of the optical device.

Specifically, consider the case where the EC element 1 is incorporated as an optical filter in the camera system. At this time, the function of the camera system is to acquire an image by forming an image of light from the subject on the image sensor. Therefore, the region that passes through the EC element 1 when the light from the subject reaches the effective pixels of the image pickup device fulfills the function of dimming the EC element 1 as an optical filter in order to appropriately perform the imaging function of the camera system. It is a region, and the region is an effective optical region.

Further, specifically consider the case where the EC element 1 is incorporated as an optical filter in the dimming window system. At this time, the function of the dimming window system is to dimm the light coming from one of the two regions separated by the window through the EC element 1 as an optical filter and deliver it to the observer in the other region. .. Therefore, the region where the light coming from one of the two regions separated by the window passes through the EC element 1 when reaching the observer in the other region is the effective optical region.

As a specific example of specifying the analysis region 24, the method specified in the examples of the present specification will be given. In the embodiment of the present specification, in the acquired image 23, a rectangular area having the maximum area within the area surrounded by the sealing seal 12 is set, and the rectangular area is determined by the following four conditions. The area was designated as an analysis area 24, which will be described later.
(I) The long side is 0.8 times (ii) The short side is 0.74 times (iii) The center of gravity is the same (iv) The long side is parallel to the long side of the original rectangle

Next, the R value, the B value, and the G value of all the pixels included in the analysis area 24 are averaged to obtain a reference RGB value. Further, the analysis region 24 is divided into a total of 256 rectangular regions of 16 vertical × 16 horizontal, and the color difference ΔE ₀₀ between the average RGB value and the reference RGB value in each region is calculated using the color difference formula based on the definition of CIEDE 2000. The color difference formula of CIEDE2000 is described in Sharma, Gaurav; Wu, Wencheng; Dalal, Edul N. et al. See "The CIEDE2000 color-difference formula: Implementation notes, supplementary test data, and mathematical observations" Color Research & Applications30 (1), 5 (1), 5 (1). _{The maximum value of the color difference ΔE 00} of each point obtained in this way is taken as the absolute value of the color unevenness at each time.

Applications of the EC element 1 of the present invention include a display device, a variable reflectance mirror, a variable transmission window, an optical filter, and the like. When color unevenness occurs in these application applications, the color balance of transmitted light or reflected light changes unintentionally at each point on the EC element surface, which is not preferable in any of the applications.

Regarding the value of ΔE ₀₀ , consider a case where the EC element 1 is used as an optical filter of a camera, particularly as an ND filter, as an example. If color unevenness occurs in the EC element 1 used as the ND filter, the color tone changes at each point of the image obtained by imaging. Specifically, when the sealing seal 12 used for the EC element 1 is an anode-priority sealing seal, the anodic compound is colored (typically red) in the region 13a closest to the sealing seal. Appears strongly. As a result, when the degree of color unevenness caused by the sealing seal 12 is large, the quality of the acquired image is significantly deteriorated, which is not preferable.

As described above, when the EC element 1 is used for an application such as an optical filter, it is required that the degree of color unevenness is suppressed. Specifically, it is preferable that the color difference ΔE ₀₀ is 3.2 or less. The reason for this is that, in general, when the color difference between the two colors is 3.2 or less, the two colors are judged to be the same color by human visual confirmation. That is, even when the EC element 1 is used as an optical filter, it _{is important that the maximum value of ΔE 00} in the plane satisfies the condition of 3.2 or less in order to maintain the quality of the acquired image. As a result, for example, it is possible to prevent an object from appearing greenish or reddish at the peripheral portion of the screen rather than the color at the central portion.

[Optical filter, lens unit, imaging device]
The EC element 1 of the present invention can be used in an optical filter. The optical filter of the present invention has an EC element 1 and an active element connected to the EC element 1. The active element is an element that adjusts the amount of light transmitted through the EC element 1, and specific examples thereof include a switching element for controlling the transmittance of the EC element 1. Examples of the switching element include a TFT and a MIM element. The TFT is also called a thin film transistor, and a semiconductor or an oxide semiconductor is used as a constituent material thereof. Specific examples thereof include amorphous silicon, low-temperature polysilicon, and semiconductors made of InGaZnO as a constituent material.

The EC element 1 of the present invention can be used in an image pickup apparatus and a lens unit. The image pickup apparatus of the present invention includes the above-mentioned optical filter having the EC element 1 and a light receiving element that receives light that has passed through the optical filter.

Further, the lens unit of the present invention includes the above-mentioned optical filter having the EC element 1 and an imaging optical system. The imaging optical system is preferably a plurality of lenses or lens groups. The optical filter may be arranged so that the light passing through the optical filter passes through the imaging optical system, or the light passing through the imaging optical system may be arranged so as to pass through the optical filter. Further, the optical filter may be arranged between a plurality of lenses. The optical filter is preferably provided on the optical axis of the lens. The amount of light that has passed through the imaging optical system or the amount of light that has passed through can be adjusted by using an optical filter.

FIG. 9 is a diagram schematically showing an example of an image pickup apparatus and a lens unit using an optical filter. FIG. 9A has an imaging device having a lens unit 42 using an optical filter 41 and an imaging unit 43, and FIG. 9B has an imaging unit 43 having an optical filter 41 and a lens unit. The imaging devices are shown respectively. As shown in FIG. 9A, the lens unit 42 is detachably connected to the image pickup unit 43 via a mount member (not shown).

The lens unit 42 is a unit having a plurality of lenses or lens groups. For example, in FIG. 9A, the lens unit 42 represents a rear-focus type zoom lens that focuses after the aperture. The lens unit 42 has a first lens group 44 having a positive refractive power, a second lens group 45 having a negative refractive power, and a third lens group 46 having a positive refractive power in order from the subject side (left side when facing the paper surface). It has four lens groups of a fourth lens group 47 having a positive refractive power. The distance between the second lens group 45 and the third lens group 46 is changed to perform magnification change, and a part of the lens groups of the fourth lens group 47 is moved to perform focusing. The lens unit 42 has, for example, an aperture diaphragm 48 between the second lens group 45 and the third lens group 46, and an optical filter between the third lens group 46 and the fourth lens group 47. Has 41. The light passing through the lens unit 42 is arranged so as to pass through each lens group 44 to 47, the aperture diaphragm 48 and the optical filter 41, and the amount of light can be adjusted by using the aperture diaphragm 48 and the optical filter 41. ..

Further, the configuration inside the lens unit 42 can be changed as appropriate. For example, the optical filter 41 can be arranged in front of (subject side) or behind (imaging unit 43 side) of the aperture diaphragm 48, or may be arranged before the first lens group 44, and may be arranged in front of the first lens group 44, and may be arranged in front of the first lens group 44. It may be placed after 47. If it is arranged at a position where light converges, there is an advantage that the area of the optical filter 41 can be reduced. Further, the form of the lens unit 42 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 any other 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.

The image pickup unit 43 includes a glass block 49 and a light receiving element 50. The glass block 49 is a glass block such as a low-pass filter, a face plate, or a color filter. Further, the light receiving element 50 is a sensor unit that receives light that has passed through the lens unit 42, and an image pickup element 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 light intensity or wavelength information can be appropriately used.
When the optical filter 41 is incorporated in the lens unit 42 as shown in FIG. 9A, the driving means such as the active element may be arranged inside the lens unit 42 or outside the lens unit 42. good. When it is arranged outside the lens unit 42, the EC element 1 inside and outside the lens unit 42 and the driving means are connected through wiring to control the driving.

As shown in FIG. 9B, the image pickup apparatus itself may have an optical filter 41. The optical filter 41 may be arranged at an appropriate position inside the image pickup unit 43, and the light receiving element 50 may be arranged so as to receive light that has passed through the optical filter 41. In FIG. 9B, for example, the optical filter 41 is arranged immediately before the light receiving element 50. When the image pickup device itself has an optical filter 41 built-in, the connected lens unit 42 itself does not have to have the optical filter 41, so that it is possible to configure a dimmable image pickup device using an existing lens unit. It becomes.

Such an imaging device can be applied to a product having a combination of light intensity adjustment and a light receiving element. For example, it can be used for cameras, digital cameras, video cameras, and digital video cameras, and can also be applied to products with a built-in imaging device such as mobile phones, smartphones, PCs, and tablets.
By using the optical filter of the present invention as a dimming member, the amount of dimming can be appropriately changed by one filter, which has advantages such as reduction in the number of members and space saving.
According to the optical filter, the lens unit, and the image pickup apparatus of the present invention, it is possible to suppress color unevenness caused by the sealing seal in the EC element. Therefore, it is possible to suppress deterioration of the quality of the image obtained by imaging the light transmitted or reflected by the optical filter.

[Window material]
The window material of the present invention has an EC element 1 of the present invention and an active element connected to the EC element 1. 10A and 10B are views schematically showing an example of the window material of the present invention, FIG. 10A is a perspective view, and FIG. 10B is a sectional view taken along the line AA'of FIG. 10A.

The window material 61 of FIG. 10 is a dimming window, and is composed of an EC element 1, transparent plates 61a and 61b sandwiching the EC element 1, and a frame 62 that surrounds and integrates the whole. The active element (not shown) is an element that adjusts the amount of light transmitted through the EC element 1, and may be directly connected to the EC element 1 or indirectly connected to the EC element 1. Further, the active element may be integrated in the frame 62, or may be arranged outside the frame 62 and connected to the EC element 1 through wiring.

The transparent plates 61a and 61b are not particularly limited as long as they are materials having high light transmittance, and are preferably glass materials in consideration of use as windows. In FIG. 10, the EC element 1 is a component independent of the transparent plates 61a and 61b, but for example, the substrates 10a and 10b of the EC element 1 may be regarded as the transparent plates 61a and 61b.

The frame 62 may be made of any material, but any material that covers at least a part of the EC element 1 and has an integrated form may be regarded as a frame.

Such a dimming window can also be called a window material having an electronic curtain, and when the EC element 1 is in the decolorized state, a sufficient amount of transmitted light can be obtained with respect to the incident light, and in the colored state, the incident light is reliably blocked and blocked. Modulated optical properties are obtained. The window material of the present invention can be applied to, for example, an application for adjusting the amount of sunlight incident into a room during the daytime. Since it can be applied to adjust the amount of heat as well as the amount of sunlight, it can be used to control the brightness and temperature of a room. It can also be applied as a shutter to block the view from the outside to the inside. Such dimming windows can be applied not only to glass windows for buildings, but also to windows for vehicles such as automobiles, trains, airplanes, and ships, and filters for display surfaces of clocks and mobile phones.

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

[Manufacturing of EC element]
An EC element 1 having the structure shown in FIG. 1 was manufactured by the following method.
Two transparent conductive glass substrates (10a, 10b) on which an indium-doped tin oxide (ITO) film (electrodes 11a, 11b) was formed were prepared. Two through holes (not shown) were formed on one of the substrates. Next, using a thermosetting epoxy resin (manufactured by Mitsui Chemicals, “Structbond HC-1850”) containing gap control particles (50 μm), two substrates were attached so that the electrodes (11a, 11b) face each other. I matched it.

Next, the cathodic EC compound (viologen derivative) represented by the following structural formulas 1 and 2 and the anodic EC compound (dihydrophenazine derivative) represented by the following structural formula 3 are dissolved in propylene carbonate at the concentrations shown in Table 1. , A total of 12 kinds of EC solutions were prepared. Note that the D _A '/ D _C' in Table 1 shows the ratio of the effective diffusion coefficient of the anodic EC compound and cathodic EC compound as described above. The characteristics of the EC compounds used are shown in Table 2. The values of the diffusion coefficient shown in Table 2 are measured by using the above-mentioned chronoamperometry method.

Next, the EC solutions 1 to 12 were filled in the space partitioned by the opposing electrodes (11a, 11b) and the sealing seal 12 via the above-mentioned through holes to obtain the EC layer 13. Next, the through holes were sealed with an ultraviolet curable acrylic resin to obtain an EC element 1.

[Evaluation of color unevenness]
The EC element was arranged so that the element surface was horizontal. Next, as shown in FIG. 8, an image pickup device 22 (Canon Eos kiss x5) was arranged above the EC element 1 and a surface illumination 21 was arranged below the element 1 so that the optical axis was perpendicular to the element surface. .. The EC element 1 was driven by applying a voltage of 0.7 V between the anode and the cathode, and images were acquired at intervals of 30 minutes for 24 hours immediately after the EC element was driven. The R value, B value, and G value of all the pixels included in the analysis area 24 described above were averaged to obtain a reference RGB value. Further, the analysis area 24 is divided into a total of 256 rectangular areas of 16 vertical × 16 horizontal, and the color difference ΔE ₀₀ between the average RGB value and the reference RGB value in each area is obtained by using the color difference formula based on the definition of CIEDE2000. Calculated. _{The maximum value of the color difference ΔE 00} of each point obtained in this way was taken as the absolute value of the color unevenness at each time, and the evaluation was performed with the absolute value of the color unevenness after 24 hours.

〔Evaluation results〕
First, a voltage was applied to the EC element 1 filled with the solution 1 to bring it into a colored state, and then the coloring spectra of the element central portion 15 and the sealing seal nearest neighbor 13a were acquired. From the obtained spectral shape, it was confirmed that the anodic EC compound was preferentially colored in the vicinity 13a of the sealing seal. Further, when the polarity of the voltage applied to the EC element 1 was reversed and the coloring spectrum of 13a closest to the sealing seal was confirmed again, the preferential coloring of the anodic EC compound was confirmed as before the inversion. From the above results, it was confirmed that the sealing seal of the example was an anode-priority sealing seal.

Figure 11 is a graph showing the value of D _A '/ D _C' which is the ratio of the effective diffusion coefficient of the anodic EC compound and cathodic EC compound, the relationship between Delta] E ₀₀ is an indicator of color unevenness. From Figure 11, in the _{0.8 ≦ D A '/ D C} '<1 range, it was confirmed that the color unevenness satisfies the conditions of the aforementioned Delta] E ₀₀ ≦ 3.2 is remarkably suppressed, in _{particular, 0.951 ≦ D a '/ D} C'< be further uneven color in one range is highly inhibited was confirmed.
From this example, the following effects were confirmed.
A EC element complementary in EC element tight seal 12 is an anode preferentially tight seal, anodic EC compound and an effective diffusion coefficient of the cathodic EC compound ratio D _A '/ D _C' is 0. the _{8 ≦ D a '/ D C} ' satisfy the <1, it is possible to highly suppress the color unevenness caused by the tight seal 12.
Furthermore, by D _A '/ D _C' satisfies _{0.951 ≦ D A '/ D C} '<1, can be more highly suppressed color unevenness caused by the tight seal 12.
The _{0.8 ≦ D A '/ D C} '<1 or _{0.951 ≦ D A '/ D C} '<EC element satisfying 1, even at concentrations higher than 0.1 mol / L concentration of EC compound, Color unevenness caused by the sealing seal 12 can be highly suppressed.
The same effect was confirmed in the EC element in which the sealing seal 12 is a cathode-priority sealing seal.

1: EC element, 11a: 1st electrode, 11b: 2nd electrode, 12: Sealing seal, 13: EC layer, 41: Optical filter, 42: Lens unit, 44-47: Lens group, 50: Light receiving element

Claims (12)

The first electrode, the second electrode, the sealing seal arranged between the first electrode and the second electrode, the first electrode, the second electrode, and the sealing. It has an electrochromic layer, which is arranged in a space partitioned by a stop seal, and has.
The electrochromic layer is an electrochromic device having an anodic electrochromic compound and a cathodic electrochromic compound.
The sealing seal is an anode-priority sealing seal in which the oxidation reaction of the anodic electrochromic compound is prioritized in the vicinity of the sealing seal.
The electrochromic the effective diffusion coefficient D _A of the anodic electrochromic compound in electrochromic layer ', the electrochromic the effective diffusion coefficient D _C of the cathodic electrochromic compounds in electrochromic layer', and when, the following equation (I) An electrochromic element characterized by satisfying.
_{0.8 ≦ D A '/ D C} '<1 (I)
[D _A ': the electrochromic anodic electrochromic compound total value across all the anodic electrochromic compound contained the product in the electrochromic layer of the individual concentrations and the diffusion coefficient of the anodic electrochromic compound in electrochromic layer The value obtained by dividing by the sum of the concentrations of.
D _C ': the cathodic electrochromic compound total value of over all cathodic electrochromic compound contained the product in the electrochromic layer of the individual concentrations and the diffusion coefficient of the cathodic electrochromic compounds in the electrochromic layer The value obtained by dividing by the total concentration. ] The electrochromic device of claim 1, wherein the D _A 'and the D _C' is characterized by satisfying the following formula (II).
_{0.951 ≦ D A '/ D C} '<1 (II) The first electrode, the second electrode, the sealing seal arranged between the first electrode and the second electrode, the first electrode, the second electrode, and the sealing. It has an electrochromic layer, which is arranged in a space partitioned by a stop seal, and has.
The electrochromic layer is an electrochromic device having an anodic electrochromic compound and a cathodic electrochromic compound.
The sealing seal is a cathode-priority sealing seal in which the reduction reaction of the cathodic electrochromic compound is prioritized in the vicinity of the sealing seal.
The electrochromic the effective diffusion coefficient D _C of the cathodic electrochromic compounds in electrochromic layer ', the electrochromic the effective diffusion coefficient D _A of the anodic electrochromic compound in electrochromic layer', and when, the following equation (III) An electrochromic element characterized by satisfying.
_{0.8 ≦ D C '/ D A} '<1 (III)
[D _C ': cathodic electrochromic compound total value of over all cathodic electrochromic compound contained the product in the electrochromic layer of the individual concentrations and the diffusion coefficient of the cathodic electrochromic compounds in the electrochromic layer The value obtained by dividing by the sum of the concentrations of.
D _A ': the electrochromic anodic electrochromic compound total value across all the anodic electrochromic compound contained the product in the electrochromic layer of the individual concentrations and the diffusion coefficient of the anodic electrochromic compound in electrochromic layer The value obtained by dividing by the total concentration. ] The electrochromic device of claim 3, wherein the D _C 'and the D _A' is characterized by satisfying the following formula (IV).
_{0.951 ≦ D C '/ D A} '<1 (IV) Any one of claims 1 to 4, wherein the sum of the concentration of the anodic electrochromic compound and the concentration of the cathodic electrochromic compound in the electrochromic layer is 0.1 mol / L or more. The electrochromic element described in the section. Any one of claims 1 to 4, wherein the sum of the concentration of the anodic electrochromic compound and the concentration of the cathodic electrochromic compound in the electrochromic layer is 0.3 mol / L or more. The electrochromic element described in the section. The electrochromic device according to any one of claims 1 to 6, wherein the electrochromic layer further has a solvent. The electrochromic device according to any one of claims 1 to 7, wherein the anodic electrochromic compound and the cathodic electrochromic compound are organic compounds. An optical filter comprising the electrochromic element according to any one of claims 1 to 8 and an active element connected to the electrochromic element and driving the electrochromic element. A lens unit comprising the optical filter according to claim 9 and a plurality of lenses or lens groups. An image pickup apparatus comprising the optical filter according to claim 9 and a light receiving element that receives light transmitted through the optical filter. A window material comprising the electrochromic element according to any one of claims 1 to 8 and an active element connected to the electrochromic element.

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