JP2000338528A - Optical device and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical element in which close adhesion property of layers consisting of conductive particles such as a carbon material is enhanced and the potential of the element is stabilized, and which reduces the energy consumption and has a longer life and high reliability, and to provide a method for its production. SOLUTION: A third layer 19 consisting of an electricity collector is formed on a glass substrate 5, on which a second layer 20 consisting of a conductive polymer layer and a first layer 18 consisting of a binder containing conductive particles are formed to constitute a counter electrode 17b. Thereby, the adhesion property between the first layer 18 and the third layer 19 is enhanced by the second layer 20 consisting of the polymer layer to stabilize the potential of the counter electrode 17b. Further, the local concentration of an electric field in the first layer 18 is decreased to suppress precipitation of inactive particulate silver.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device and a method of manufacturing the same, for example, by displaying numbers or characters or X-rays.
It is suitable for a display device for performing Y matrix display or the like, or an optical filter capable of controlling light transmittance or light reflectance in a visible light region (wavelength λ = 400 to 700 nm).

[0002]

2. Description of the Related Art Conventionally, an electrochromic display element (hereinafter, may be abbreviated as “ECD”) has been employed in a display device such as a voltage-driven digital timepiece. The ECD is a non-light-emitting type display element, and has an advantage that, as an electrochemical dimming element, the display is based on reflected light or transmitted light, so that the feeling of fatigue is small even after long-time observation.

For example, as disclosed in JP-A-59-24879, a liquid type ECD using an organic molecular viologen molecule derivative which reversibly forms a colored / decolored state as an EC material is disclosed. Are known.

However, when an EC material such as a viologen molecule derivative is used for an ECD device, there is a problem in that the response speed and the degree of shielding are insufficient. Moreover, as a light amount adjusting device, a visible light region (wavelength: 400 to 700) is used.
nm), it is necessary to be able to control the light transmittance, but sufficient properties were not obtained with the above EC materials.

Therefore, the present inventor has replaced ECD with
Focusing on dimming devices using deposition / dissolution of metal salts, and studying electrochemical dimming devices using deposition / dissolution of silver. As a result, characteristics superior to EC materials in response speed and degree of shielding. Could be obtained.

According to such an optical device, when an electrolyte solution is prepared, the solution is in the visible light range (wavelength: 400 to 400 nm).
Reversible plating which causes silver precipitation / dissolution of a silver (complex) salt having no absorption at 700 nm) and capable of substantially evenly shielding in the visible light region when colored, that is, RED (Reversible Electrode). -Deposition), and the silver (complex) salt has a high possibility of precipitation / dissolution by drive control. On the other hand, with respect to the precipitation of silver from a silver (complex) salt, a cyan-based solution used as a plating bath has been conventionally known. However, with a cyan-based solution, it is necessary to secure a safe working environment and to treat the waste liquid. There's a problem. From this point, in the present invention, it is desirable to use a non-cyanide silver salt.

Therefore, by using a reversible system for depositing / dissolving silver from a silver (complex) salt on a transparent electrode, that is, RED (Reversible E) which is a reversible plating material.
By using an electro-deposition material, an optical device such as an optical filter suitable for a non-light-emitting visible light region with low power consumption can be manufactured.

FIGS. 10 and 11 show the cell structure of this conventional electrochemical light control device.

As shown in FIGS. 10A and 11, a pair of transparent glass substrates 24 and 25 are arranged as display windows at a predetermined interval. As shown in FIG. 10A, the inner surfaces of each of the substrates 24 and 25 are made of ITO (Indium Tin Oxide).
xide: obtained by doping indium oxide with tin)
Working electrodes 22 and 23 are provided to face each other, and a silver salt solution 21 is disposed between the working electrodes 22 and 23 facing each other. Reference numeral 26 denotes a counter electrode made of a silver plate provided also as a spacer on the entire periphery between the substrates 24 and 25.

The silver salt solution 21 is, for example, a solution obtained by dissolving silver bromide in dimethyl sulfoxide (DMSO). As shown in the figure, a counter electrode 26 is used as an anode, and working electrodes 22 and 23 are used as cathodes. When a DC driving voltage is applied for a certain time, an oxidation-reduction reaction of Ag ⁺ + e ⁻ → Ag occurs in the silver salt on the cathode side, and the Ag deposits cause the working electrodes 22 and 23 on the cathode side to change from transparent to colored. . FIG. 10B is a principle view showing the operation at this time.

As described above, Ag on the working electrodes 22 and 23
Is deposited, a specific color (for example, reflected light) due to the Ag deposit is observed from the display window. The filtering action by the coloring, that is, the transmittance of visible light (or shading of the coloring) changes with the magnitude of the voltage or the application time thereof, and therefore, by controlling them, the cell is made to have a variable transmittance display element or It can function as an optical filter.

On the other hand, in this colored state, when a DC voltage is applied between the counter electrode 26 and the working electrodes 22 and 23 in a direction opposite to that described above, the working electrode 2 on which Ag is deposited is applied.
2 and 23 are now on the anode side, where a reaction of Ag → Ag ⁺ + e ⁻ occurs, and the Ag deposited on the working electrodes 22 and 23 is dissolved in the silver salt solution 21. As a result, the working electrodes 22 and 23 that were in the colored state are restored to the colored-to-transparent state.

FIGS. 12 and 13 show another conventional electrochemical light control device.

In this example, as shown in the cross-sectional view of FIG. 12, a pair of transparent glass substrates 4 and 5 constituting a cell are arranged at regular intervals, and each pair of transparent glass substrates 4 and 5 is Working electrodes 2a, 2b, 2c, 2d made of ITO
2e and 3a, 3b, 3c, 3d, 3e are provided facing each other. Counter electrodes 7a, 7 made of a silver plate are provided on the outer peripheral portions of these working electrodes 2a to 2e and 3a to 3e.
b is provided. The substrates 4 and 5 are held at a predetermined interval by a spacer 6, between which the silver salt solution 1 is sealed.

As shown in the plan view of FIG.
a to 2e, 3a to 3e and the counter electrodes 7a and 7b are formed in a concentric pattern. Each electrode 2a and 3a, 2b and 3b, 2c and 3c, 2d and 3d, 2e and 3e, 7a and 7
b denotes drive power sources 8a, 8b, 8c, 8d, 8e,
8f, wirings 9a, 9b, 9c, 9 made of a thin chrome wire or the like.
d, 9e, 9f.

In this configuration, the working electrodes 2 opposed to each other
a and 3a, 2b and 3b, 2c and 3c, 2d and 3d, 2e
And 3e at predetermined potentials (V ₁ , V ₂ , V ₃ , V ₄ , V _{4
Assume 5} . V ₆ is a reference potential at the counter electrodes 7a and 7b. )
To give a silver salt solution 1 on each electrode as a cathode.
Can be precipitated and colored. The filtering action by the coloring, that is, the transmittance of visible light (or the shading of the coloring) changes with the magnitude of the voltage or the application time.

Therefore, if V ₁ = V ₂ = V ₃ = V ₄ = V ₅ , the cell can be colored uniformly over the entire area, and the density can be changed according to the voltage or the application time. The degree can be varied uniformly. Also, for example, | V ₁
If | <| V ₂ | <| V ₃ | <| V ₄ | <| V ₅ |, the color density increases from the center to the periphery (in other words, the transmittance decreases). ). Conversely, | V ₁ |
> | V ₂ |> | V ₃ |> | V ₄ |> | V ₅ |
The transmittance increases from the center to the periphery. This configuration is useful as an optical diaphragm for a CCD (Charge Coupled Device) of a television camera or the like, and can sufficiently cope with an improvement in the integration degree of the CCD.

[0018]

In the above-mentioned conventional electrochemical dimming device, a metal plate such as a solid silver plate is used as the counter electrode 26, 7a, or 7b as it is, resulting in a problem of high cost. there were. In addition, as the life of the device is prolonged, inactivated silver particles deposited on the counter electrode float in the silver salt solution, fouling the device, causing a decrease in transmittance when the device is transparent, and causing a decrease in the transmittance between the electrodes. There is also a problem that this may cause a short circuit.

For example, in the elements shown in FIGS. 12 and 13, when the working electrode is decolorized, the counter electrodes 7a and 7
At this time, as shown in FIG. 14 (7b is shown in the figure), the lines of electric force of the electric field are concentrated on the sharp corners of the electrodes. Silver grows relatively large in grains and precipitates. This granular silver A
Is not easily dissolved even when the working electrode is colored, unlike the thin-film silver B in other parts, and is separated and suspended in the silver salt solution 1 in a granular inert state as shown in the figure. . When such inert silver particles increase in the silver salt solution, the transparency of the device at the time of decoloring of the working electrode decreases, and the silver particles cause a short circuit between the electrodes.

Therefore, the present inventor has taken measures to solve this problem, for example, by collecting a layer containing at least one kind of conductive particles such as a carbon material instead of using a metal plate such as a solid silver plate as a counter electrode as it is. Consider the method of forming on the body,
An optical device such as an electrochemical dimming element and a method for manufacturing the same are proposed in Japanese Patent Application No. 10-9458 (filed on January 21, 1998).

However, according to this patent application (hereinafter, referred to as the prior application), the counter electrode can be made of a relatively inexpensive material, and inactive silver particles are hardly formed on the counter electrode. Although having performance, it was found that there is still room for improvement.

That is, when a carbon material is used as a counter electrode,
When the device is driven and a number of redox reactions of silver are repeated at the transparent electrode and the counter electrode, electric charges are supplied to the carbon material, but the counter electrode itself does not electrochemically react with the electrolytic solution, etc. The adhesion between the body and the carbon material may be reduced, and the layer of the carbon material may be separated from the current collector.

In such a state, the current collector comes into direct contact with the electrolytic solution without going through the carbon material layer, and directly participates in the reaction with the electrolytic solution. In such a case, if the current collector is made of a material in which charge transfer to the electrolyte is not performed smoothly, the interface polarization becomes extremely large.

In a material in which charge transfer to the electrolyte is performed relatively smoothly, side reactions such as precipitation of silver or a compound containing silver on the current collector or decomposition of components of the electrolyte occur. If the precipitate has an insulating property, the subsequent charge transfer will not be performed smoothly, resulting in a very large polarization. Such a large polarization not only requires a large power consumption, but also has a problem of shortening the life of the device for further promoting a side reaction.

Therefore, an object of the present invention is to improve the adhesion of a layer made of conductive particles such as a carbon material, so that the above-mentioned peeling does not occur, and the potential of the counter electrode is stabilized to enable stable driving. It is another object of the present invention to provide an optical device and a manufacturing method for realizing low power consumption and long life of an element.

Another object of the present invention is that, for example, a counter electrode of an electrochemical optical device utilizing a precipitation / dissolution reaction of silver can be made of a relatively inexpensive material, and the counter electrode is not formed on the counter electrode. An object of the present invention is to provide an optical device such as an electrochemical dimmer having a configuration in which active silver particles are hardly formed, and a method of manufacturing the same.

[0027]

That is, the present invention has a working electrode and a counter electrode, and an electrolytic solution composed of a silver salt solution is disposed in contact with both of the electrodes. In an optical device that is electrochemically modulated, the counter electrode includes a first layer made of conductive particles, a second layer made of a polymer layer, and a third layer made of a current collector. An optical device according to the present invention, wherein two layers are formed between the first layer and the third layer (hereinafter, referred to as an optical device of the present invention).

According to the optical device of the present invention, the polymer layer as the second layer joins the first layer made of the conductive particles and the third layer made of the underlying current collector to improve adhesion. Can be enhanced. As a result, the potential of the counter electrode is stabilized, and the first electrode made of conductive particles accompanying the repetition of the electrochemical reaction is obtained.
The occurrence of separation between the layer and the third layer made of the underlying current collector and the increase in polarization due to the separation can be delayed, thereby suppressing an increase in power consumption and a side reaction with the electrolyte over a long period of time. In addition, the life of the optical device can be extended.

Further, since the first layer is made of conductive particles, if the first layer is formed by printing or coating a mixture of the conductive particles and a binder, it is easy to solidify the first layer into a predetermined shape, and the counter electrode is substantially sharp. Since it can be formed in a shape without a sharp corner, local electric field concentration on the counter electrode can be relaxed, and the deposition of inactive particulate silver etc. on the counter electrode is suppressed or prevented it can. As a result, for example, it is possible to prevent the inactive silver particles from floating in the silver salt solution to lower the transparency of the device or to short-circuit the electrodes.

Further, the present invention has a working electrode and a counter electrode, and an electrolytic solution comprising a silver salt solution is disposed in contact with both electrodes, and the light is electrochemically dimmed by an electric field applied to the electrolytic solution. In the method of manufacturing an optical device to be performed, a second layer made of a polymer layer is formed on a third layer made of a current collector by electrochemical polymerization, and a first layer made of conductive particles is formed on the second layer. The present invention relates to a method for manufacturing an optical device characterized by forming a layer (hereinafter, referred to as a manufacturing method of the present invention).

According to the manufacturing method of the present invention, since the second layer of the optical device of the present invention is formed by electrochemical polymerization, a dense and uniform polymer layer can be formed, and the first layer can be formed. Since it is formed as a coating layer or the like made of conductive particles, it is possible to manufacture the optical device of the present invention having the above-described functions and effects with good reproducibility.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described.

In the above-described optical device and the manufacturing method of the present invention, at least a part of the first layer of the counter electrode includes:
It is desirable to contain at least one kind of conductive particles and at least one kind of binder.

In this case, it is desirable that the conductive particles are composed of at least one selected from the group consisting of silver and a carbon material, and the binder is a natural rubber, a cellulose, or a phenol. It is desirable to be made of at least one resin material selected from the group consisting of urethane-based and epoxy-based.

Preferably, at least a part of the first layer of the counter electrode is composed of silver particles, conductive particles other than silver, and the binder, and printing, coating or sintering of a mixture thereof. It is desirable to form at least a part of the first layer of the counter electrode.

[0036] In this case, the silver particles are used with respect to the component comprising the conductive particles other than the silver particles and the binder.
It is desirable to add 0.01 to 100 times by weight ratio from the viewpoint of stabilization of the potential of the counter electrode and ease of preparing the mixture, and the addition amount is further 0.05 to 10 times. (The same applies hereinafter).

Specifically, the silver particles have a solid content of 0.01 to 100 times (more preferably 0.05 to 10 times) the solid content of the paste composed of the conductive particles other than the silver particles and the binder.
It is desirable to add at a weight ratio of (2).

That is, in the optical device of the present invention, by forming the counter electrode with the conductive particles contained in the binder, it is possible to reduce the cost, improve the transmittance of the element, and prevent the short circuit between the electrodes. It can also be considered that the spectral characteristics attributed to the driving voltage of the element are also improved by replacing the counter electrode material.However, the conductive particles are contained in the binder or sintered to form the counter electrode. Due to the formation, silver is taken into the counter electrode during driving and shows a potential different from that of the silver plate, or the counter electrode is made of a chemically unstable material (silver precipitates and the composition of the counter electrode changes).
Therefore, drive control may be difficult.

However, by adding silver particles to a binder together with other conductive particles (or adding silver-plated or silver-deposited conductive particles to a binder or sintering, as described later). By forming at least a part of the first layer of the counter electrode (in other words, by adding silver to this electrode), the potential of the electrode can be stabilized.

The potential of the counter electrode is 50 times higher than the potential of the silver electrode.
It is effective if the silver particles are added to a paste consisting of the conductive particles and the binder when the difference is positive or negative, which is not less than mV. If the counter electrode is different from the potential of the silver electrode by | 50 mV | or more, precipitation of silver,
Since the dissolution hardly occurs, the potential of the electrode is made equal to that of the silver electrode or a potential at which silver precipitation and dissolution are easily caused by the addition of the silver particles (or silver-plated or silver-deposited conductive particles described later). (The same applies hereinafter).

Further, at least a part of the first layer of the counter electrode can be formed by printing or coating a mixture of conductive particles other than silver, which has been previously subjected to silver plating or silver evaporation, and the binder.

Also in this case, the silver plated or silver-deposited silver is 0.01 to 100 times (more preferably 0.1 to 100 times) the component composed of the conductive particles other than the silver and the binder.
(0.5 to 10 times) is desirable for the reason described above.

Specifically, the silver which has been subjected to the silver plating or the silver deposition is 0.01 to 100 times (more preferably 0.05 to 100 times) the solid content of the paste comprising the conductive particles other than the silver and the binder. -10 times).

Then, at least a part of the first layer of the counter electrode is formed by printing or coating a paste obtained by pulverizing a conductive material other than silver, which has been previously silver-plated or silver-deposited, and then mixing with the binder. Is good.

The potential of the counter electrode is 50 times higher than the potential of the silver electrode.
When the difference is not less than mV and positive or negative, it is preferable to add the silver-plated or silver-deposited conductive particles to the binder.

In the above-described optical device of the present invention, for example, at least a part of the first layer of the counter electrode comprises a sintered layer of silver particles and conductive particles other than silver, and When the potential is different from the potential of the silver electrode by 50 mV or more, positively or negatively, it is desirable to form the sintered layer in terms of stabilizing the potential of the electrode.

[0047] At least a part of the first layer of the counter electrode may be formed of a sintered layer of conductive particles other than silver, which is previously silver-plated or silver-deposited.

In this case, at least a part of the first layer of the counter electrode may be formed by pulverizing a conductive material other than silver, which has been previously silver-plated or silver-deposited, after pulverizing, and further sintering. . By this preforming, a shape in which the corner of the counter electrode does not substantially already exist can be obtained.

The potential of the counter electrode is 50 times higher than the potential of the silver electrode.
If the difference is more than mV, positive or negative, the conductive material may be sintered after grinding and preforming.

Further, it is preferable that the second layer is formed of at least one kind of conductive polymer material, and this conductive polymer material is formed by an electrochemical polymerization method. Preferably, polyaniline, polypyrrole, or polythiophene is used as the conductive polymer material.

Further, the third layer of the counter electrode can be constituted by a metal foil or a conductive thin film.
The working electrode may be made of the same material.

It is important that substantially no corner exists at the edge of the counter electrode.

Thus, a pair of transparent or semi-transparent substrates disposed opposite to each other, the working electrode provided on at least one of the opposing surfaces of the pair of transparent or semi-transparent substrates, Thus, an optical device having the silver salt solution disposed between the pair of transparent or translucent substrates and the counter electrode disposed in contact with the silver salt solution can be formed.

In this case, the transparent or translucent electrode may be made of indium-tin oxide.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the drawings.

<First Embodiment> First, FIGS. 1 and 2
A first embodiment in which the present invention is applied to the same optical filter (electrochemical light control element) as described with reference to FIGS. 12 and 13 will be described with reference to FIG.

In the first embodiment, as shown in FIG. 2, a pair of transparent substrates (for example, glass substrates) 4 and 5 constituting a cell are arranged at regular intervals. 5 on the inner surface (opposing surface), a pair of working electrodes (for example, ITO electrodes) 2a, 2b, 2c, 2d, 2e and 3
a, 3b, 3c, 3d, and 3e are provided facing each other. The substrates 4 and 5 are held at a predetermined interval by a spacer 6, between which the silver salt solution 1 is sealed.

In the present embodiment, unlike the conventional examples shown in FIGS. 12 and 13, the counter electrodes 17a and 17b provided on the outer peripheral portions of the working electrodes 2a to 2e and 3a to 3e are configured as follows. are doing. That is, the counter electrode 17b in FIG.
As shown in FIG. 1, a third layer 19 made of a current collector is formed on the substrates 4 and 5, and a second layer 20 made of a polymer layer is formed thereon by electrochemical polymerization. Then, a kind of paste-like conductive paint in which conductive particles and a binder are mixed is printed or applied thereon to form the first layer 18 to form the counter electrodes 17a and 17b. The working electrodes 2a to 2e and 3a to 3e and the counter electrodes 17a, 17
The plane shape of b is substantially the same as that shown in FIG. 27a and 27b indicate reference poles.

That is, in the optical device of this embodiment, the polymer layer is interposed between the current collector and the layer made of the conductive particles, and the first layer and the third layer of the counter electrodes 17a and 17b are formed by the polymer layer.
The layers are joined to improve the adhesion.

Such a polymer layer is preferably made of a conductive polymer in order to smoothly transfer charges from the current collector to the conductive particle layer. Various methods such as a casting method and a vapor deposition method can be used to form the conductive polymer layer. Among them, an electrochemical polymerization method is preferably used. That is, in the electrochemical polymerization method, a dense polymer layer can be uniformly formed by using electrolysis.

In the electrochemical polymerization method, an object to be formed is immersed in a solution having monomer molecules, and the current is applied to the object to polymerize the monomer molecules to form a polymer on the surface of the object ( The details will be described later). The types of conductive polymers formed by this electrochemical polymerization method include polyaniline using aniline as a monomer, polypyrrole using pyrrole as a monomer, and polythiophene using thiophene as a monomer.

Further, aniline, pyrrole, thiophene, and the like are easily chemically modified, so that various derivatives are present, and derivative polymers are accordingly present. For example, in polyaniline, the derivatives N-alkylaniline, N, N
Polymers such as -dimethylaniline, 1-aminopyrene and σ-phenylenediamine; polymers such as N-methylpyrrole as derivatives of polypyrrole; alkyl groups, alkoxyl groups and allyl groups at positions 3 and 4 of thiophene in polythiophene There is a polythiophene derivative substituted with

The synthesis of a polymer by electrochemical polymerization is shown in FIG.
This is performed by a cell 46 as shown in FIG. To carry out the polymerization,
If possible, it is preferable to provide a cock 44 into which an inert gas can be introduced in order to remove oxygen from the air. Usually, a polymer obtained by polymerizing a polymer (substrate 5) is used as the positive electrode 48 and the negative electrode 47 is used.
Use an appropriate electrode material.

When an appropriate concentration of the monomer to be polymerized is dissolved in the solvent which has been deoxygenated by blowing an inert gas, and an appropriate voltage 41 is applied between the two electrodes in the electrolytic solution 49, the positive electrode 4
8 forms the desired polymer. 42 in the figure is an ammeter,
43 is a voltmeter and 45 is a lid.

For example, when aniline is electrochemically polymerized, aniline is added to an aqueous solution (pH <2) of hydrochloric acid, sulfuric acid, perchloric acid, tetrafluoroboric acid or the like in an amount of about 0.2 to 1 m.
When ol / l is melted and oxidized by applying a constant potential or a constant current of 0.7 to 1.0 V using ITO as a positive electrode and silver as a reference electrode, polyaniline is formed on the ITO on the film.

When electrochemically polymerizing pyrrole, for example, acetonitrile is used as a solvent, the concentration of pyrrole is 0.05 to 0.1 mol / l, ITO is used as a positive electrode, platinum is used as a negative electrode, and about 3 When a voltage of .5V is applied,
Polypyrrole forms on the ITO.

Further, when thiophene is electrochemically polymerized, benzonitrile, tetrahydrofuran, methylene chloride and the like are often used as a solvent in addition to acetonitrile, and platinum, nickel, graphite and the like can be used for a negative electrode. When a voltage is applied to the positive electrode as ITO, polythiophene is formed on the ITO.

Usually, in order to carry out electrochemical polymerization, an electrolyte is dissolved in order to conduct a sufficient current value. For example,
In the electrochemical polymerization of polyaniline, the above-mentioned hydrochloric acid or the like is added to make it acidic to about pH 1, and when the polypyrrole or polythiophene is electrochemically polymerized, bromide contained in the electrolytic solution used in the optical device of the present invention is used. In addition to silver salts such as silver, lithium salts such as lithium iodide and lithium perchlorate are used as the electrolyte. In such an electrochemically polymerized film, an anion of the electrolyte is taken in as a dopant at the same time as the polymerization, so that a film having high conductivity can be obtained.

The conditions for carrying out the electrochemical polymerization vary depending on the type of the monomer, the solvent and the driving method. In order to obtain a good film, for example, in the case of polymerization of polyaniline at a constant current, 3
mA / cm ² or less, more preferably 0.5 mA / cm ²
It is desirable that

In electrochemical polymerization, copolymerization, for example, copolymerization of pyrrole and thiophene is not possible because the oxidation potentials of the two monomers are different, but 2,2'-thienylpyrrole and 2,5-di ( By using a derivative such as 2-thienyl) -pyrrole as a monomer, a 1: 1 or 2: 1 alternating copolymer of thiophene and pyrrole can be synthesized.

The second polymer layer may be formed of an insulating polymer. In this case, if the second layer is formed thin, electric current can be passed.

As described above, after the second layer is formed by performing electrochemical polymerization on the counter electrode portion, a layer containing conductive particles is applied or printed to form the first layer.

Preferably, the thickness of the first layer is several μm to several tens μm, the thickness of the second layer is 50 to 500 nm, and the thickness of the third layer is 100 to 400 nm. The third layer,
It is provided on an insulating substrate (thickness is, for example, about 1 mm) of glass, fiber reinforced plastic (FRP), etc.
It may be made of copper, silver, gold, platinum, SUS or the like.

Examples of the carbon material used for the conductive particles include graphite (graphite), graphitizable carbon (soft carbon), non-graphitizable carbon (hard carbon), carbon black, and activated carbon.

Here, graphitizable carbon (soft carbon)
Is a carbon material that becomes graphitized when heat-treated at about 2800 to 3000 ° C., and non-graphitizable carbon (hard carbon) is a carbon material that does not become graphitized even when heat-treated at about 3000 ° C.

The graphitizable carbon can be obtained, for example, by depositing coal or pitch in a nitrogen stream at a rate of 1 to 20 ° C./min.
It is produced by baking under the conditions of about 0 to 1300 ° C and a holding time at the ultimate temperature of about 0 to 5 hours. The pitch is
It is obtained by distillation (vacuum distillation, atmospheric distillation, steam distillation, etc.), thermal polycondensation, extraction, chemical polycondensation, etc. from tars and asphalt obtained by high-temperature pyrolysis of coal tar, ethylene bottom oil, crude oil, etc. Or pitch generated during wood carbonization.

Further, the graphitizable carbon may be a polyvinyl chloride resin, polyvinyl acetate, polyvinyl butyrate,
It is also produced by carbonizing a high-molecular compound material such as 3,5-dimethylphenol resin in a nitrogen stream at 300 to 700 ° C. and then baking it under the same conditions as described above.

Further, graphitizable carbon includes naphthalene, phenanthrene, anthracene, triphenylene, pyrene,
Condensed polycyclic hydrocarbon compounds such as perylene, pentaphene, and pentacene and derivatives thereof (for example, carboxylic acids, carboxylic anhydrides, and carboxylic imides thereof);
A mixture of each of the above compounds, acenaphthylene, indole,
Condensed heterocyclic compounds such as isoindole, quinoline, isoquinoline, quinoxaline, phthalazine, carbazole, acridine, phenazine, phenanthridine and derivatives thereof are also produced by carbonization and calcination as described above.

On the other hand, non-graphitizable carbon is produced by, for example, carbonizing and calcining a furfuran resin composed of a homopolymer or copolymer of furfuryl alcohol or furfural under the same conditions as in the case of the above-mentioned graphitizable carbon. .

Further, the non-graphitizable carbon is converted into petroleum pitch having a specific H / C atomic ratio (for example, 0.6 to 0.8).
It is also produced from an organic material into which a functional group containing oxygen has been introduced (so-called oxygen crosslinking). For example, non-graphitizable carbon materials
Organic polymer compounds such as phenolic resin, acrylic resin, vinyl halide resin, polyimide resin, polyamideimide resin, polyamide resin, conjugated resin, cellulose and derivatives thereof having an H / C atomic ratio of 0.6 to 0.8. And condensed polycyclic hydrocarbon compounds such as naphthalene, phenanthrene, anthracene, triphenylene, pyrene, perylene, pentaphene, and pentacene, and derivatives thereof (for example, carboxylic acids, carboxylic anhydrides, and carboxylic imides thereof); Various pitches containing a mixture of each compound as a main component, acenaphthylene, indole, isoindole, quinoline, isoquinoline, quinoxaline, phthalazine, carbazole, acridine, phenazine, phenazine, fused heterocyclic compounds and derivatives thereof, as described above Under the conditions of charcoal And it is generated by firing.

The above-described carbonization and calcination may be performed after adding a phosphorus compound to the starting material or precursor of the graphitizable carbon and the non-graphitizable carbon described above.

When the conductive particles of the present invention are made of graphite (graphite), natural graphite or, for example, the above-mentioned graphitizable carbon is used as a precursor and artificial graphite is heat-treated at a high temperature of 2000 ° C. or more. Can be used.

The following table shows the characteristics of graphite (graphite), graphitizable carbon (soft carbon), non-graphitizable carbon (hard carbon) and activated carbon in comparison.カ ー ボ ン Carbon species Crystallinity Density Porosity Firing temperature Conductivity ─ ─────────────────────────────────── Graphite High High Large Small High High High Soft carbon ↓ ↓ ↑ ↓ ↓ Hard carbon ↓ ↓ ↑ ↓ ↓ Activated carbon low small large large low low low ───────────────────────────────── ───

In the present invention, the binder used by mixing with the above-mentioned conductive particles may be any one which has resistance to the silver salt solution 1. For example, a natural rubber type, a cellulose type, a phenol type, a urethane type or an epoxy type may be used. A system resin can be used. The mixing ratio of the binder to the conductive particles is preferably in the range of about 80:20 to about 99: 1 by weight, and more preferably in the range of about 90:10 to about 99: 1. If the mixing ratio is less than 80:20, the strength of the resulting film may be too weak. On the other hand, if the mixing ratio is more than 99: 1, the conductive particles may be relatively small and may be required. Conductivity may not be obtained.

As described above, the counter electrodes 17a and 17b are provided between the first layer 18 composed of the mixture of the conductive particles and the binder and the third layer 19 composed of the current collector.
By interposing a layer, the first layer 18
Can be prevented from peeling off.

The conductive particles constituting the mixture of the conductive particles and the binder contain at least one kind of carbon material, but may also contain other metals or alloys such as silver and copper or nickel, or compounds. Can be used alone or in combination. Among them, silver particles are particularly preferably used in order to have an effect of stabilizing the potential of the counter electrode.

The particle size of the conductive particles is preferably from several μm to several tens μm. If the particle size is too small or too large, the conductive particles are uniformly dispersed in the binder. And the electrical resistance of the film may be too high.

For the current collector constituting the third layer, a material having electron conductivity and being electrochemically stable is used. Examples of current collector materials that can be used for the electrolytic solution used in the light control device of the present embodiment include Group 4A and Group 6A of the periodic table.
Examples include at least one metal material selected from Group 8 and Group 1B and alloys thereof, and metal oxides such as ITO.

When the pastes are printed or applied to form the counter electrodes 17a and 17b, for example,
As shown in FIG. 1 (a), which is an enlarged view of a portion b, and FIG. 1 (b), which is an enlarged view thereof, the corners of the edges are rounded due to the fluidity and surface tension of the material, and substantially, The counter electrodes 17a and 17b having no corners are formed. Therefore, the electric field concentration as described with reference to FIG. 14 is alleviated, and as a result, silver deposited from the silver salt solution 1 is prevented from being formed in a relatively large granular form. That is, in the first embodiment, inactive silver particles floating in the silver salt solution 1 and causing a decrease in the transparency of the element when the working electrode is decolored or a short circuit between the electrodes. Is prevented from being formed on the counter electrodes 17a and 17b.

As described above, by forming the counter electrodes 17a and 17b in a laminated structure with a layer of a mixture of conductive particles and a binder, a polymer layer, and a layer of a current collector as a base, a conventional silver plate or the like is used. An optical device having stable characteristics can be formed without floating silver particles, as compared with a case where a metal plate is used.

Providing a reference electrode in the above-described optical device is effective for performing stable control of the working (transparent) electrode and the counter electrode.

That is, as shown in FIG. 2, the reference pole 27a,
By providing 27b in the electrolytic solution 1, accurate potentials of the working electrode and the counter electrode in the electrolytic solution are obtained, and the working electrodes 2a to
2e, 3a to 3e and the potential of the counter electrodes 17a and 17b can be controlled with high precision, and a limiter that controls an external power supply so that the potential difference between the working electrode or the counter electrode and the reference electrode is kept within a predetermined range. With the provision, excessive polarization of the working electrode or the counter electrode can be prevented, and deterioration of the element can be suppressed.

As the metal used for the current collector, tantalum, niobium, etc. can be used in addition to the metal shown at the counter electrode. Tantalum and niobium do not use tantalum and niobium because they have a higher specific resistance than others, so if they are used for the current collector of the counter electrode, the polarization will increase.However, only a small current is used for the reference electrode to monitor the potential. Since they do not flow and the potential of the reference electrode hardly changes, these metals can also be used for the current collector of the reference electrode.

Specifically, the configuration of such an optical device is such that a pair of transparent or semi-transparent substrates disposed opposite to each other and a pair of transparent or semi-transparent substrates are provided on opposing surfaces thereof. At least one pair of transparent or translucent electrodes (particularly, a transparent electrode such as ITO having a light transmittance of 70% or more in the visible light region) disposed so as to face each other and the at least one pair of transparent or translucent electrodes. And a counter electrode having a stacked structure and being in contact with the electrolytic solution and having a silver salt.

In the first embodiment, as the silver salt solution 1, a solution in which silver halide such as silver bromide, silver chloride, silver iodide or the like is dissolved in water or a non-aqueous solvent can be used. . At this time, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), diethylformamide (DEF), N, N-dimethylacetamide (DMAA), N-methylpropionamide (MPA), N-methyl Pyrrolidone (MP), propylene carbonate (PC), acetonitrile (AN), 2
-Methoxyethanol (MEOH), 2-ethoxyethanol (EEOH) and the like can be used.

The concentration of silver halide in the silver salt solution is preferably from 0.03 to 2.0 mol / l,
More preferably, it is 0.05 to 2.0 mol / l.

It is preferable to add a supporting salt (supporting electrolyte) capable of supplying bromine and other halogens for increasing the conductivity of the silver salt solution and dissolving the silver halide. For example, sodium halide, potassium halide, calcium halide, quaternary ammonium halide, and the like can be used for this purpose. Such a supporting salt is preferably added in a concentration range of about 1/2 to 5 times the silver halide.

Further, by chemically or physically modifying an ITO electrode, which is a working electrode for depositing or dissolving silver, for example, the polarization value required for depositing silver on the ITO electrode is reduced, and Deposition can be facilitated, and electrical damage to the ITO electrode and the solution itself can be reduced.

As a chemical modification method in this case, it is preferable to perform a surface treatment (chemical plating) of the ITO electrode with palladium or the like by a two-liquid treatment method of a tin solution and a palladium solution. That is, as a surface activation treatment of the ITO electrode with palladium, the activity on the surface of the ITO electrode is increased by depositing a palladium nucleus on the ITO-only substrate.

In this case, the tin solution may be tin chloride (Sn
Cl ₂ ) 0.10 to 1.0 g in a concentration of 0.010 to 0.1
Palladium chloride (PdCl ₂ ) 0.10 to 0% dissolved in 1 liter of HCl.
1.0 g of a concentration of 0.010 to 0.10% and 1 liter of HC
1 can be used.

As a physical modification method, a method of depositing a metal or the like, which is nobler than silver, on the ITO electrode can be adopted.

<Second Embodiment> Next, a second embodiment of the present invention will be described.
In the second embodiment, the element structure of the second embodiment is substantially the same as that of the first embodiment shown in FIGS. 1 and 2. The embodiment will also be described with reference to FIGS.

In the second embodiment, the counter electrode 17a,
17b is formed by sintering conductive particles. Other configurations are the same as those of the above-described first embodiment.

As the conductive particles, as in the first embodiment described above, silver and other metals or alloys, graphite (graphite), easily graphitizable carbon (soft carbon), and non-graphitizable carbon ( Hard carbon), carbon black, activated carbon and other carbon materials can be used alone or in combination. The particle size of the conductive particles is preferably several μm to several tens μm. If the particle size is smaller than this range, the amount of the conductive particles used for the required film thickness is relatively large and the cost is high. On the other hand, if the particle size is larger than the above range, the voids in the film obtained by sintering become too large, and the mechanical strength of the film becomes weak, or the electric resistance may become too high. There is.

In the second embodiment, when sufficient mechanical strength is obtained by sintering, it is not particularly necessary to mix a binder with the conductive particles. Of course, the mixture may be sintered after the binder is mixed. In that case, the binder described in the first embodiment can be used as the binder.

In the second embodiment, conductive particles such as metal and carbon material are preformed and sintered to form a counter electrode 17a.
Since 17b is formed and fixed to the substrate by bonding or the like, the amount of material used can be reduced as compared with the case where a dense metal plate or the like is used, and as a result, the counter electrodes 17a, 17b
Material cost can be reduced.

The counter electrode 17 obtained by sintering the powder
The shapes of a and 17b are formed into a powder layer of a predetermined shape by preliminary molding before sintering, and are obtained by sintering, so that the shapes of the powder layers are substantially equal to the shape of the powder layer. Therefore, for example, FIG.
And (b), the counter electrodes 17a and 17b having substantially no corners are formed. Therefore, the electric field concentration as described with reference to FIG. 14 is alleviated, and as a result, silver deposited from the silver salt solution 1 is prevented from being formed in a relatively large granular form. That is, also in the second embodiment, inactive silver particles floating in the silver salt solution 1 and causing a decrease in the transparency of the element when the working electrode is decolored or a short circuit between the electrodes. Is prevented from being formed on the counter electrodes 17a and 17b.

[0108]

EXAMPLES Hereinafter, examples of the optical filter manufactured according to the preferred embodiment of the present invention will be described. Embodiment 1 First, referring to FIG. 2, an embodiment in which the present invention is applied to an optical filter (electrochemical dimmer) similar to that described in FIGS. 12 and 13 will be described.

In this embodiment, as shown in FIG. 2, a pair of transparent substrates 4 and 5 made of glass constituting a cell are arranged at regular intervals, and an inner surface (opposing surface) of each of the substrates 4 and 5 is ITO.
Working electrodes 2a, 2b, 2c, 2d, 2
e and 3a, 3b, 3c, 3d, and 3e were provided to face each other. The substrates 4 and 5 are held at predetermined intervals by spacers 6, and the silver salt solution 1 is sealed between them.

The working electrodes 2a-2e and 3a-3
The counter electrodes 17a and 17b provided on the outer peripheral portion of e were configured as follows. That is, an ITO film was formed to a thickness of about 200 nm on the substrates 4 and 5 by sputtering to form a current collector layer. The plane shapes of the working electrodes 2a to 2e and 3a to 3e and the counter electrodes 17a and 17b are substantially the same as those shown in FIG.

Thereafter, using the apparatus shown in FIG. 3, the substrate was immersed in an aqueous solution of aniline, and electricity was applied to the ITO portions corresponding to the counter electrodes 17a and 17b, whereby polyaniline was electrochemically polymerized on the ITO surface. .

The aqueous solution of aniline used above was prepared by mixing 5 ml of aniline with 10 ml of hydrochloric acid and 35 ml of pure water. The electrochemical polymerization of polyaniline was performed at a constant current of 0.5 mA / cm ² for 2 minutes.

After the polyaniline is electrochemically polymerized on the ITO surface in this manner, it is sufficiently washed with water and dried, and a paste obtained by mixing conductive particles and a binder is printed thereon, and the counter electrodes 17a, 17b Was formed.

Also, the polyaniline was not electrochemically polymerized, and only the paste was printed on ITO at a thickness of about 20 μm to produce counter electrodes 17a and 17b of Comparative Example 1.

Silver salt solution 1 contains 500 mM of silver bromide and 750 mM of sodium iodide in dimethyl sulfoxide (DM
The light control devices of Example 1 and Comparative Example 1 were assembled using a solution dissolved in a mixed solvent of (SO) / acetonitrile (AN) = 55/45.

The working electrode of these light control elements, ITO,
Electrodes 2a, 2b, 2c, 2d, 2e and 3a, 3b, 3
c, 3d, and 3e were passed through a constant current between the counter electrodes 17a and 17b to precipitate and dissolve silver on the ITO electrode. The current density was 18 mA / cm ^{2 at the} ITO electrode. Electricity was applied for 2 seconds for both dissolution. This is one cycle of silver precipitation and dissolution.

By repeating the above oxidation-reduction cycle, 2
At 10,000 times or more, in Comparative Example 1, the electrolytic solution turned yellow, whereas in Example 1, no discoloration of the electrolytic solution was observed.

In order to investigate the cause, a transparent electrode 5 similar to that used in Example 1 and Comparative Example 1 was obtained by using a silver plate 53 as a reference electrode by a beaker cell 46 shown in FIG.
4 and the counter electrode 52, the change in the potential difference (cell voltage) of the ITO electrode with respect to the counter electrode when the oxidation-reduction cycle was repeated so that the current density at the transparent electrode became 18 mA / cm ² as described above, and the silver plate 53 (Reference pole)
Changes in the potential of the TO electrode and the counter electrodes 17a and 17b were measured. In the figure, 42 is an ammeter, 50 is a voltmeter, and 51 is a constant current source.

In the beaker cell 46 shown in FIG. 4, the counter electrode 52 is formed by forming an ITO film on a rectangular glass substrate, electrochemically polymerizing polyaniline, and printing a carbon paste.
By adjusting the immersion area, a predetermined current density was applied.

FIG. 5 shows the change over time of the potential of the counter electrode of Example 1 during the oxidation-reduction cycle, and FIG. 6 shows the change over time of the potential of the counter electrode of Comparative Example 1. According to FIGS. 5 and 6, the potential of the transparent electrode does not show a large change in the polarization potential even when the oxidation-reduction cycle is repeated, but the polarization potential of the counter electrode gradually increases as the number of oxidation-reduction cycles increases. You can see it rises.

FIG. 7 shows the results obtained in Example 1 and Comparative Example 1.
The maximum value of the polarization during the counter-electrode oxidation in the redox cycle is plotted and shown. According to this, in Example 1, the maximum value of the polarization during oxidation was suppressed to about 1.5 V even when the number of oxidation-reduction cycles reached 30,000, whereas Comparative Example 1
When the oxidation-reduction cycle exceeds 20,000 times, the maximum value of the polarization during oxidation becomes 2 V or more.

In such a case, for example, it is considered that the main cause is that the iodine ion I ⁻ ionized from the sodium iodide as the supporting electrolyte dissolved in the electrolytic solution is oxidized. Changes such as yellowing of the liquid occur. Such discoloration of the electrolytic solution adversely affects the spectral characteristics of the optical element.

Thus, according to Example 1, the electrolyte solution did not turn yellow and good spectral characteristics were maintained even after many oxidation-reduction cycles, so that the life of the optical element was extended. .

Example 2 In this example, the counter electrodes 17a, 17a, 17a and 17b were formed in the same manner as in Example 1 except that polypyrrole was electrochemically polymerized instead of polyaniline in Example 1.
b. That is, the substrate was immersed in a solution containing pyrrole, and electricity was passed through ITO serving as a base for the counter electrodes 17a and 17b, polypyrrole was electrochemically polymerized, and then a carbon paste was printed.

The pyrrole solution used above is prepared by using acetonitrile, which has been deoxygenated by blowing an inert gas, as a solvent, at a pyrrole concentration of 0.1 mol / l, and lithium iodide as a supporting electrolyte. . When the substrate is immersed in this solution and a potential of about 3.5 V is applied to ITO serving as a base of the counter electrode, polypyrrole is generated on the ITO.

[0127] By sufficiently washing with acetonitrile and then drying, polypyrrole doped with iodine ion as an electrolyte anion can be obtained. The method of assembling and evaluating the bonded cells in each of the following examples is the same as in the first embodiment.

In the bonded cell of this example, even when the oxidation-reduction cycle accompanying the precipitation and dissolution reaction of silver was repeated 30,000 times, yellowing of the electrolytic solution as in the comparative example was not observed. Further, as in Example 1, the polarization potential of the counter electrode was examined using a beaker cell. FIG. 8 shows the result.

According to this, the maximum value of the polarization potential during oxidation of the counter electrode gradually increases as the number of redox cycles increases, but is suppressed to about 1.5 V with respect to silver even after repeating 30,000 times. However, unlike the comparative example, the electrolyte does not yellow. Accordingly, in the second embodiment, similarly to the first embodiment, it is possible to realize a longer life of the optical element.

Example 3 In this example, the counter electrodes 17a, 1a and 1a were used in the same manner as in Example 1 except that polythiophene was electrochemically polymerized instead of polyaniline in Example 1.
7b. That is, the substrate is immersed in a solution containing thiophene, and ITO as a base for the counter electrodes 17a and 17b is
, The polythiophene was electrochemically polymerized, and then a carbon paste was printed.

The thiophene solution used in the above was prepared by using acetonitrile, which had been deoxygenated by blowing an inert gas, as a solvent, with a thiophene concentration of 0.1 mol / l, and lithium iodide dissolved as a supporting electrolyte. .
When the substrate is immersed in this solution and a potential of about 3.5 V is applied to ITO serving as a base of the counter electrode, polythiophene is formed on the ITO. If sufficiently washed with acetonitrile and dried, polythiophene doped with iodide ions, which are electrolyte anions, can be obtained.

In the bonded cell of this example, even if the oxidation-reduction cycle accompanying the precipitation and dissolution reaction of silver was repeated 30,000 times, yellowing of the electrolytic solution as in Comparative Example 1 was not observed. Further, as in Example 1, the polarization potential of the counter electrode was examined using a beaker cell. FIG. 9 shows the result.

According to this, the maximum value of the polarization potential during oxidation of the counter electrode gradually increases as the number of redox cycles increases, but is suppressed to about 1.5 V with respect to silver even after repeating 30,000 times. However, unlike the comparative example, the electrolyte does not yellow. Accordingly, in the third embodiment, similarly to the first embodiment, it is possible to realize a longer life of the optical element.

According to each of the above-described embodiments, the third layer made of the current collector and the first layer made of the conductive particles are joined to each other. In the case where the second layer composed of a molecular layer is formed by an electrochemical polymerization method, the polarization of the counter electrode can be performed regardless of whether polyaniline, polypyrrole, or polythiophene is used as the conductive polymer even if the redox cycle reaches 30,000 times. The potential does not fluctuate greatly, is suppressed to about 1.5 V, and the electrolyte does not yellow. However, when electrochemical polymerization is not performed (when the second layer made of a conductive polymer is not provided), the polarization potential of the counter electrode rapidly increases when the number of oxidation-reduction cycles exceeds 20,000, and is 2 V or more. At the same time, since the electrolytic solution turns yellow, the optical filter according to the present embodiment can maintain good spectral characteristics and extend the life of the element.

The embodiments described above can be variously modified based on the technical concept of the present invention.

For example, each of the above-described three-layer counter electrode layers may be formed of a plurality of layers. For example, the second
When the layer is composed of two layers, the upper layer uses a material compatible with the first layer made of an organic material, and the lower layer uses a material compatible with the third layer made of an inorganic material. In the case where the first layer is composed of two layers, a layered structure in which the silver-containing binder layer is coated with silver can improve the conductivity while maintaining the roundness of the corners of the first layer. . Of course, at least the surface of the first layer on the silver salt solution side of the counter electrode may be formed of a layer containing conductive particles by coating or the like. (In this case, the base may be made of a normal metal.)

In addition to the first to third layers, a fourth or higher layer structure having a different function may be employed. In addition, the above-described conductive particles are not limited to the same type, and a plurality of types may be mixed (combined), or the above-described second layer may be formed of a mixture of a plurality of types of conductive polymers.

The electrode pattern is not limited to concentric circles, but can be variously changed, such as stripes and grids.
Further, a different cell can be provided for each divided electrode.

The optical device described above can be used in combination with other known filter materials (for example, organic electrochromic materials, liquid crystals, electroluminescent materials, etc.).

Further, the above-described optical device can be widely applied to light amount adjustment of various optical systems such as an optical communication device of an electrophotographic copying machine, including an optical diaphragm of a CCD. Further, in addition to the optical filter, the present invention can be applied to various image display devices for displaying characters and images.

[0140]

As described above, the present invention has a working electrode and a counter electrode, and an electrolyte composed of a silver salt solution is disposed in contact with both electrodes, and the electric field is applied by an electric field applied to the electrolyte. In a chemically dimmed optical device, the counter electrode is:
A first layer made of conductive particles, a second layer made of a polymer layer, and a third layer made of a current collector, wherein the second layer is located between the first layer and the third layer. Since it is formed, the polymer layer that is the second layer includes the first layer made of conductive particles,
The adhesiveness can be increased by bonding the third layer made of the base current collector. As a result, the potential of the counter electrode is stabilized, and peeling between the first layer made of conductive particles and the third layer made of the underlying current collector occurs due to repetition of the electrochemical reaction, and the accompanying peeling occurs. Since an increase in polarization can be delayed, an increase in power consumption and a side reaction with an electrolytic solution can be suppressed for a long time, and the life of the optical device can be extended.

Further, since the first layer is made of conductive particles, if the first layer is formed by printing or coating a mixture of the conductive particles and a binder, it is easy to solidify into a predetermined shape, and the counter electrode is substantially formed. Since it can be formed in a shape without sharp corners, local electric field concentration on the counter electrode can be relaxed, and suppression of deposition of inactive particulate silver or the like on the counter electrode can be suppressed or Can be prevented. As a result, for example, it is possible to prevent the inactive silver particles from floating in the silver salt solution to lower the transparency of the device or short-circuit between the electrodes, thereby improving the reliability.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a counter electrode of an optical filter according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of an optical filter according to an embodiment of the present invention.

FIG. 3 is a schematic diagram showing an apparatus for electrochemical polymerization.

FIG. 4 is a schematic diagram showing a beaker cell.

FIG. 5 is a graph showing changes over time of a counter electrode potential and a current value when a silver precipitation / dissolution cycle is performed according to Example 1 of the present invention.

FIG. 6 is a graph showing a change over time of a counter electrode potential and a current value when a silver precipitation / dissolution cycle is performed in Comparative Example 1.

FIG. 7 is a graph plotting the maximum value of the polarization potential of the counter electrode when the cycle of depositing and dissolving silver is repeated at the counter electrode of Example 1 and Comparative Example 1.

FIG. 8 is a graph plotting the maximum value of the polarization potential of the counter electrode when the cycle of depositing and dissolving silver is repeated at the counter electrode of Example 2 and Comparative Example 1.

FIG. 9 is a graph plotting the maximum value of the polarization potential of the counter electrode when the cycle of depositing and dissolving silver is repeated at the counter electrode of Example 3 and Comparative Example 1.

FIG. 10 is a cross-sectional view showing a configuration and an operation principle of a conventional electrochemical light control device.

11 is an external perspective view of the device shown in FIG.

FIG. 12 is a cross-sectional view illustrating a configuration of another conventional electrochemical light control device.

FIG. 13 is a schematic plan view of the device shown in FIG.

FIG. 14 is a conceptual diagram showing a conventional problem.

[Explanation of symbols]

1, 21 ... Silver salt solution, 2a-2e, 3a-3e, 22,
23 ... working electrode (ITO electrode), 4, 5, 24, 25 ...
Glass substrate, 6 spacer, 7a to 7b, 17a, 1
7b: counter electrode, 18: conductive particle layer, 19: underlying conductive layer,
20: polymer layer, 26: counter electrode and spacer, 27a, 2
7b, 53: Reference electrode, 41: Power supply, 42: Ammeter, 43
... voltmeter, 44 ... two-way cock, 45 ... stopper, 46 ... beaker, 47 ... negative electrode, 48 ... positive electrode, 49 ... solution, 50 ... voltmeter, 51 ... constant current source, 52 ... counter electrode

Claims (58)

[Claims] 1. An optical device having a working electrode and a counter electrode, an electrolytic solution made of a silver salt solution being disposed in contact with both of these electrodes, and being electrochemically dimmed by an electric field applied to the electrolytic solution. In the above, the counter electrode is a first layer made of conductive particles,
An optical element comprising a second layer made of a polymer layer and a third layer made of a current collector, wherein the second layer is formed between the first layer and the third layer. apparatus. 2. The optical device according to claim 1, wherein at least a part of the first layer of the counter electrode contains at least one kind of conductive particles and at least one kind of binder. 3. The conductive particles are composed of at least one selected from the group consisting of silver and a carbon material.
The optical device according to claim 1. 4. The optical device according to claim 1, wherein the binder is made of at least one resin material selected from the group consisting of natural rubber, cellulose, phenol, urethane and epoxy. apparatus. 5. The optical device according to claim 1, wherein at least a part of the first layer of the counter electrode includes silver particles, conductive particles other than silver, and the binder. 6. The method according to claim 1, wherein the silver particles are present in an amount of 0.01 to the component comprising the conductive particles other than the silver particles and the binder.
The optical device according to claim 5, wherein the optical device is added in a weight ratio of 1 to 100 times. 7. The method according to claim 6, wherein the silver particles are added in a weight ratio of 0.01 to 100 times the solid content of the paste composed of the conductive particles other than the silver particles and the binder. Optical device. 8. The potential of the counter electrode is 5 times lower than the potential of the silver electrode.
The optical device according to claim 5, wherein the silver particles are added to a paste composed of the conductive particles and the binder when the difference is positive or negative at 0 mV or more. 9. The optical device according to claim 2, wherein at least a part of the first layer of the counter electrode is made of conductive particles other than silver, which have been previously silver-plated or silver-deposited, and the binder. 10. The silver plated or silver-deposited silver,
The optical device according to claim 9, wherein the optical device is added in a weight ratio of 0.01 to 100 times the component consisting of the conductive particles other than silver and the binder. 11. The method according to claim 11, wherein the silver plated or silver-deposited silver is
The optical device according to claim 10, wherein the optical device is added in a weight ratio of 0.01 to 100 times the solid content of the paste composed of the conductive particles other than silver and the binder. 12. The method according to claim 12, wherein at least a part of the first layer of the counter electrode is formed of a paste obtained by pulverizing a conductive material other than silver, which has been previously silver-plated or silver-deposited, and then mixing the material with the binder. Item 10. The optical device according to Item 9. 13. The optical device according to claim 9, wherein the conductive particles are added to the binder when the potential of the counter electrode is positively or negatively different from the potential of the silver electrode by 50 mV or more. 14. The optical device according to claim 1, wherein the first layer of the counter electrode is made of a sintered body of conductive particles. 15. The optical device according to claim 14, wherein at least a part of the first layer of the counter electrode is formed of a sintered layer of silver particles and conductive particles other than silver. 16. The optical device according to claim 14, wherein the sintered layer is formed when the potential of the counter electrode is positively or negatively different from the potential of the silver electrode by 50 mV or more. 17. The optical device according to claim 14, wherein at least a part of the first layer of the counter electrode is formed of a sintered layer of conductive particles other than silver, which is previously silver-plated or silver-deposited. 18. The method according to claim 18, wherein at least a part of the first layer of the counter electrode is formed by pulverizing a conductive material other than silver, which has been previously silver-plated or silver-deposited, after pre-forming, and further sintering. Item 18. An optical device according to Item 17. 19. The conductive material is sintered after grinding and preforming when the potential of the counter electrode is positively or negatively different from the potential of the silver electrode by 50 mV or more.
7. The optical device according to 7. 20. The optical device according to claim 1, wherein the second layer is formed of at least one kind of a conductive polymer material. 21. The optical device according to claim 20, wherein the conductive polymer material is formed by an electrochemical polymerization method. 22. The optical device according to claim 21, wherein polyaniline is used as the conductive polymer material. 23. The optical device according to claim 21, wherein polypyrrole is used as the conductive polymer material. 24. The optical device according to claim 21, wherein polythiophene is used as the conductive polymer material. 25. The optical device according to claim 1, wherein the third layer of the counter electrode is made of a metal foil or a conductive thin film. 26. The optical device according to claim 1, wherein the third layer is made of the same material as the working electrode. 27. The optical device according to claim 1, wherein the edge of the counter electrode has substantially no corner. 28. A pair of transparent or translucent substrates disposed to face each other, the working electrode provided on at least one of the opposing surfaces of the pair of transparent or translucent substrates, The optical device according to claim 1, further comprising: the silver salt solution disposed between the pair of transparent or translucent substrates; and the counter electrode disposed in contact with the silver salt solution. 29. The optical device according to claim 28, wherein the working electrode is made of indium-tin oxide. 30. An optical device having a working electrode and a counter electrode, an electrolytic solution made of a silver salt solution being disposed in contact with both electrodes, and being electrochemically dimmed by an electric field applied to the electrolytic solution. In the method for producing the above, a second layer made of a polymer layer is formed on a third layer made of a current collector by electrochemical polymerization, and a first layer made of conductive particles is formed on the second layer. A method for manufacturing an optical device, comprising: 31. The method according to claim 30, wherein the first layer is formed by printing, coating, or sintering. 32. The method according to claim 30, wherein at least a part of the first layer of the counter electrode contains at least one kind of conductive particles and at least one kind of binder. 33. The method according to claim 30, wherein the conductive particles are made of at least one selected from the group consisting of silver and a carbon material. 34. The optical device according to claim 30, wherein the binder is made of at least one resin material selected from the group consisting of natural rubber, cellulose, phenol, urethane, and epoxy. Production method. 35. The method of manufacturing an optical device according to claim 30, wherein at least a part of the first layer of the counter electrode is made of silver particles, conductive particles other than silver, and the binder. 36. The silver particles are mixed with a component comprising conductive particles other than the silver particles and the binder in an amount of 0.0
The method for manufacturing an optical device according to claim 35, wherein the addition is performed at a weight ratio of 1 to 100 times. 37. The method according to claim 36, wherein the silver particles are added in a weight ratio of 0.01 to 100 times the solid content of the paste composed of the conductive particles other than the silver particles and the binder.
3. The method for manufacturing an optical device according to item 1. 38. The method according to claim 38, wherein the silver particles are added to a paste comprising the conductive particles and the binder when the potential of the counter electrode is positively or negatively different from the potential of the silver electrode by 50 mV or more. 35. The method for manufacturing an optical device according to 35. 39. The manufacturing of the optical device according to claim 32, wherein at least a part of the first layer of the counter electrode is formed of conductive particles other than silver, which have been previously silver-plated or silver-deposited, and the binder. Method. 40. The silver plated or silver-deposited silver,
A component consisting of the conductive particles other than silver and the binder is added in a weight ratio of 0.01 to 100 times,
A method for manufacturing an optical device according to claim 39. 41. The silver-plated or silver-deposited silver,
41. The method of manufacturing an optical device according to claim 40, wherein the weight ratio is 0.01 to 100 times the solid content of the paste composed of the conductive particles other than silver and the binder. 42. At least a part of the first layer of the counter electrode is formed of a paste obtained by pulverizing a conductive material other than silver, which has been previously silver-plated or silver-deposited, and then mixing the material with the binder. 3. The method for manufacturing an optical device according to item 1. 43. The production of the optical device according to claim 39, wherein the conductive particles are added to the binder when the potential of the counter electrode is positively or negatively different from the potential of the silver electrode by 50 mV or more. Method. 44. The method of manufacturing an optical device according to claim 30, wherein at least a part of the first layer of the counter electrode is formed of a sintered layer of silver particles and conductive particles other than silver. 45. The method of manufacturing an optical device according to claim 30, wherein the sintered layer is formed when the potential of the counter electrode is positively or negatively different from the potential of the silver electrode by 50 mV or more. 46. The manufacturing of the optical device according to claim 30, wherein at least a part of the first layer of the counter electrode is formed of a sintered layer of conductive particles other than silver, which is previously plated with silver or silver deposited. Method. 47. At least a portion of the first layer of the counter electrode is formed by pulverizing a conductive material other than silver which has been previously silver-plated or silver-deposited, pre-formed, and then sintered. 3. The method for manufacturing an optical device according to item 1. 48. When the potential of the counter electrode is positively or negatively different from the potential of the silver electrode by 50 mV or more, the conductive material is sintered after being crushed and preformed.
3. The method for manufacturing an optical device according to item 1. 49. The method according to claim 30, wherein the second layer is formed of at least one kind of a conductive polymer material. 50. The method for manufacturing an optical device according to claim 49, wherein the conductive polymer material is formed by an electrochemical polymerization method. 51. The method for manufacturing an optical device according to claim 50, wherein polyaniline is used as the conductive polymer material. 52. The method according to claim 50, wherein polypyrrole is used as the conductive polymer material. 53. The method according to claim 50, wherein polythiophene is used as the conductive polymer material. 54. The method according to claim 30, wherein the third layer of the counter electrode is made of a metal foil or a conductive thin film. 55. The method according to claim 30, wherein the third layer is made of the same material as the working electrode. 56. The method for manufacturing an optical device according to claim 30, wherein substantially no corner exists at the edge of the counter electrode. 57. A pair of transparent or translucent substrates disposed to face each other, the working electrode provided on at least one of the opposing surfaces of the pair of transparent or translucent substrates, 31. The method according to claim 30, wherein the silver salt solution disposed between the pair of transparent or translucent substrates and the counter electrode disposed in contact with the silver salt solution are formed. 58. The method according to claim 57, wherein the working electrode is made of indium-tin oxide.