JP2011257659A - Translucent flexible dimming element and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost and high-performance flexible dimming element facilitating the control of transparency and conductivity.SOLUTION: This translucent flexible dimming element comprises: a substance defined as a counter electrode and supporting an electrode active material on a surface of metal mesh having a pitch width of 1.8 mm or less and an aperture ratio of 50% or more; a functional electrode which has a substance in which a light transmittance is reversibly changed by applying electricity; and an electrolyte layer. A method for manufacturing the same is also provided.

Description

  The present invention relates to a translucent flexible light control device using a counter electrode having high light transmittance and high conductivity, and a method for manufacturing the same.

Various transparent conductive electrodes have been developed as one of the members indispensable for manufacturing various light control elements (for example, smart windows). Among them, ITO (Indium
One obtained by depositing Tin Oxide) on a glass substrate has been selected as one of the best. Recently, as the need for flexible devices has increased, the substrate material is shifting from glass to plastic. However, several problems related to the plastic substrate have been pointed out as follows.

(1) Since the annealing temperature after depositing ITO on the plastic substrate is relatively low, the surface resistance value of the ITO-deposited plastic electrode is much larger than the surface resistance value of the ITO-deposited glass electrode. This is because, since the softening temperature of the plastic substrate is relatively low, the annealing temperature must be set low, and therefore, the degree of crystallinity during annealing of the ITO film deposited thereon does not increase. As a result, the device performance (especially response speed) is damaged. For example, when electrical connection is made between the electrode bonding pins around the outside of the cell and the external power supply, the resistance difference between the end and the center of the cell is the surface resistance value of the ITO film using a plastic substrate. Is particularly increased in the case of a large value, and as a result, the response speed of the cell is significantly slowed down.

(2) The surface resistance value of the ITO / plastic electrode is reduced by providing a metal thin film under the ITO film. By setting the film thickness of the metal thin film in the range of about several tens of millimeters, the light transmittance of the composite film obtained in this way can be kept within a range suitable for the translucent light control element. However, it is practically not easy to adjust the balance between the surface resistance value and the light transmittance in this way. This is because the light transmittance is greatly reduced by slightly increasing the thickness of the metal thin film.

  In order to solve the above problem, Patent Document 1 shows the following proposal regarding an electrochromic light control device. That is, a conductive layer having a higher electrical conductivity than that of a transparent metal oxide such as ITO is disposed in a lattice shape or a comb shape. Furthermore, it has been shown that coating an organic film thereon is effective in preventing corrosion.

  It is a fact that the switching speed can be improved by minimizing the surface resistance value of the ITO film of the element by the method of Patent Document 1. However, this effect is only observed when the ITO film is relatively thin. In other words, this effect becomes ineffective as the ITO film thickness increases. On the other hand, another problem is seen when the ITO film is thin. In an electrochromic electrode having a conductive layer above or below the ITO layer, the surface resistance value of a part of the conductive layer is overwhelmingly smaller than the surface resistance value of other areas, so only the electrochromic layer in that part Changes color in a pattern. As the ITO film thickness increases, such partial electrochromism disappears, but the switching rate decreases. However, the method of Patent Document 1 is insufficient to solve the above problem.

  Further, Patent Documents 2 and 3 propose that a nanoporous conductive material (for example, activated carbon) having a large surface area such as carbon is laminated in a dot shape on a transparent conductive substrate for the same purpose as Patent Document 1. ing. It is described that an element capable of long-term stable driving can be manufactured by combining such a highly conductive / highly transparent electrode as a counter electrode with an electrochromic electrode.

  As expected from Patent Documents 2 and 3, a nanoporous conductive material having a black or dark color, such as carbon or other conductive colored polymer, has the disadvantage of reducing the contrast of the electrochromic electrode.

  Patent Document 4 discloses the following:

(1) When an electrochromic element (hereinafter abbreviated as ECD) is used as the light control element, it is effective to use “a metal thin film laminated substrate having an opening” for one or both of two electrodes arranged opposite to each other. Is. The interval between the openings of the metal film is set to 20 μm, and the thickness of the metal film at the opening is set to 10 μm or more.

(2) In the embodiment of the invention, a double color cell comprising a combination of a WO ₃ deposition electrode and an IrOx deposition electrode is exemplified, and its light transmittance is about 30% when colored, and light transmission when decolored. The rate is 70-80%.

  Regarding the cell performance of the ECD of Patent Document 4, the following problems are pointed out:

(1) As a result of the relatively large aperture ratio of the counter electrode, there is a large difference in surface area between the two electrodes, and it is difficult to balance the electrochemical equivalents of the electrode active materials of both electrodes. If the amount of the electrode active material at the counter electrode is significantly increased from that of the other electrode, the electrochemical equivalence relationship between the two electrodes is improved, but the electrode active material used here is not electrically conductive, so the counter electrode As a result, the cell switching speed becomes slow and the driving stability in the cycle test becomes poor.

(2) When the above-described cell is applied to a translucent light control device such as a “smart window”, it is too high if the light transmittance during coloring is only about 30%.

  In patent document 5, it is supposed that the electrochemical equivalent (Coulomb balance) between an electrochromic electrode and a counter electrode can be adjusted by using a porous counter electrode. That is, an electrode having a porous structure is formed by etching an alloy composed of a metal that is not easily corroded, such as Au, Pt, or Ag, and a metal that is easily corroded, such as Al, Zn, with a corrosive liquid such as a strong alkali. be able to.

  However, if there is no electrode active material on such a counter electrode, it becomes difficult to achieve coulomb balance between the two electrodes while the ECD cell is faded and repeatedly driven, and electrochromism becomes irreversible, This leads to a reduction in cell life.

Patent Document 6 discloses an electrodeposition type display in which a redox-active metal such as Ag or Zn is deposited on a porous metal substrate obtained by, for example, anodization of Al. That is, a red-active metal such as Ag is oxidized at the counter electrode, and the Ag ⁺ ions generated are moved to the other electrode, where they are reduced and deposited to form a spot image of Ag.

  In Patent Document 6, the metal ion generated by ionization of the metal at the counter electrode moves to the other electrode. Therefore, when this is combined with the electrochromic electrode, the function such as the memory property of the cell is impaired. Therefore, such a cell design cannot be brought into the concept of the present invention in a short-circuited manner.

In Patent Document 7, it is shown that a counter electrode having a thin metal wire on a transparent insulating substrate is combined with an electrochromic electrode made of tin oxide on which WO ₃ is deposited. Specifically, using a counter electrode provided with a copper fine wire on a transparent substrate, Cu oxidation and WO ₃ reduction are coupled to form an image.

  In the cell design as in Patent Document 7, there is a problem particularly in the cell life. This is because when the electrochromic agent is reduced and colored when the electrochromic agent is reduced, the fine metal wire on the transparent substrate is simultaneously oxidized with Cu, so that the counter electrode is repeatedly driven and corroded.

Japanese Patent Publication No. 6-93067 Japanese Patent No. 3315187 Japanese Patent No. 3384848 JP 2003-57685 A JP-A-57-135924 JP 2008-65028 A Japanese Utility Model Publication No. 6-76940

There are two important points that have remained unresolved in previous studies:
(1) Skillfully balance the surface resistance value and light transmittance of an electrode with fine metal wires on or under the ITO deposition substrate.
(2) Prevention of migration of metal ions generated by oxidation of fine metal wires deposited on the counter electrode.

The present invention relates to the following [1] to [14].

[1] Using a metal mesh surface having a pitch width of 1.8 mm or less and an aperture ratio of 50% or more as a counter electrode, and applying electricity thereto, the light transmittance is reversible. A translucent flexible light control element comprising a functional electrode having an electrically changing substance on its surface and an electrolyte layer.

[2] The translucent flexible light control element according to [1], wherein the metal mesh is attached to a transparent flexible plastic substrate.

[3] The material of the metal mesh is aluminum, and an electrode active material supported in a microporous structure of an aluminum oxide nanoporous structure formed by anodizing the aluminum surface is used as the counter electrode. [1] or [2].

[4] The electrode active material has a redox agent and a redox potential of +0.7 Vvs. -0.7V vs. from SCE. The translucent flexible light control element according to item [3], which is at least one compound selected from the group consisting of metals in the range of SCE.

[5] The redox potential is +0.7 Vvs. -0.7V vs. from SCE. The translucent flexible light control element according to the preceding item [4], further comprising a coating layer made of a chelating agent on a metal in the range of SCE.

[6] The translucent flexible light control device according to [4], wherein the redox agent is Prussian blue or an analog thereof.

[7] Next steps (1) to (4):
(1) Step 1: a process of attaching an aluminum sheet to a transparent plastic substrate,
(2) Step 2: a step of providing a through hole in the aluminum sheet to which the transparent plastic substrate is attached in Step 1;
(3) Step 3: a step of providing nanopores on the aluminum surface provided with through holes in Step 2, and (4) Step 4: a step of supporting an electrode active material inside the nanopores:
The manufacturing method of the translucent flexible light control element of any one of the preceding clauses [2] to [6] containing.

[8] In step 4, the redox potential is +0.7 Vvs. -0.7V vs. from SCE. The method for producing a translucent flexible light control device according to [7] above, which is a step of supporting a metal in the range of SCE.

[9] Following step 4, the following (5):
(5) Step 5: Redox potential is +0.7 Vvs. -0.7V vs. from SCE. The manufacturing method of the translucent flexible light control element of the preceding clause [8] in which the process of coat | covering a chelating agent on the metal in the range of SCE is performed.

[10] The method for producing a translucent flexible light control device according to [7], wherein the electrode active material is Prussian blue or an analog thereof.

[11] The translucent type according to [1], wherein the metal mesh is placed in a solid or quasi-solid type electrolyte layer, and the electrolyte layer is sandwiched between two functional electrodes. Flexible dimming element.

[12] The translucent flexible light control element according to [11], wherein the material of the metal mesh is one or more metals selected from the group consisting of tungsten and stainless steel.

[13] The translucent flexible light control element according to [11] or [12], wherein the electrode active material is applied almost uniformly on the surface of the metal mesh.

[14] Next steps (1) to (3);
(1) Step 1: a process of supporting an electrode active material on a metal mesh,
(2) Step 2: Step of floating the metal mesh carrying the electrode active material in Step 1 in the solid or quasi-solid type electrolyte layer, and (3) Step 3: Step 2 of floating the metal mesh in The sandwiched electrolyte layer between two functional electrodes:
The manufacturing method of the translucent flexible light control element of the preceding clause [11] containing.

  In the present invention, by adjusting parameters such as the pitch width, aperture ratio, and line width of the metal mesh used for the counter electrode of the element, the balance between the light transmittance and the conductivity of the electrode is optimized. It has become possible to optimize device performance (eg, contrast, switching speed, etc.).

  In addition, the redox agent and redox potential are +0.7 Vvs. -0.7V vs. from SCE. By supporting at least one selected from the group of electrode active materials such as metals within the SCE range and a chelating agent, if necessary, high performance and length without corrosion of metal electrodes It has become possible to manufacture a device having a lifetime. In particular, the redox potential is +0.7 Vvs. -0.7V vs. from SCE. By combining a chelating agent with a metal in the range of SCE, it is possible to prevent the metal ions generated by the oxidation of the metal on the counter electrode from diffusing into the functional electrode, and as a result, the memory performance of the device can be improved. it can.

It is a top view of a transparent flexible electrode regarding the 1st aspect of this invention. It is sectional drawing of the transparent flexible electrode of FIG. The cell of the structure where the solid or quasi-solid electrolyte layer which suspended the counter electrode which consists of a metal mesh between two functional electrodes was pinched | interposed regarding the 2nd aspect of this invention is shown. It is a conceptual diagram of the counter electrode which uses aluminum which has the layer by which the fine hole was formed in the surface by the anodic oxidation, and uses a metal layer. It is a conceptual diagram of the counter electrode by which silver was introduce | transduced inside the fine hole formed by anodizing aluminum. It is a SEM photograph of the surface plated with silver on the anodized aluminum substrate. It is drawing of a honeycomb-shaped through-hole.

  In order to solve the above-mentioned several problems, in the present invention, a functional electrode using an electrochromic material as a substance that changes light transmittance or reflectance by applying electricity, and a surface of a metal mesh. A translucent flexible dimming element comprising a counter electrode (hereinafter abbreviated as a counter electrode) carrying an electrode active material and an electrolyte layer is proposed.

Light-transmissive flexible light control device The best mode of the present invention will be exemplified below.
First, the translucent flexible light control element according to the first embodiment of the present invention will be described. The translucent flexible dimming element according to the best mode includes a functional electrode (electrochromic electrode) that is oxidized or reduced by applying electricity, and a counter electrode having an electrode active material supported on the surface of a metal mesh. And an electrochromic device (ECD) comprising an electrolyte layer. Hereinafter, each component of the ECD will be described in detail.

《Counter electrode》
The counter electrode according to the best mode is a highly translucent and highly conductive electrode having an electrode active material supported on the surface of a metal mesh having a pitch width of 1.8 mm or less and an aperture ratio of 50% or more.

Such metal mesh is roughly divided into the following two (1) to (2);
(1) A metal sheet is affixed to a substrate, and a large number of through-holes are provided on the substrate and patterned into a mesh. (2) A metal thin wire is woven by a textile process and processed into a mesh. What is manufactured by doing.

  Since the metal mesh (1) is made on a transparent flexible plastic substrate, the metal mesh (1) is used together with the substrate when it is used as an electrode. That is, the obtained electrode is a transparent flexible electrode having a laminated structure composed of a transparent flexible plastic substrate and a metal sheet having a large number of through holes.

  FIG. 1 is a top view of the transparent flexible electrode according to the metal mesh (1), and FIG. 2 is a cross-sectional view of the transparent flexible electrode of FIG. In the transparent flexible electrode 1, a metal 12 is disposed on a transparent flexible plastic substrate 11, and a through hole 13 is provided in the metal 12. As can be seen from FIGS. 1 and 2, the metal sheet 12 has a large number of through holes 13. When such a metal sheet having a large number of through-holes is used as a counter electrode, the element operates skillfully without covering the entire counter electrode surface with a transparent conductive material such as ITO or FTO (fluorine-doped tin oxide). It is preferable that the pitch width of one through hole is in the range of 1.0 to 2.0 mm. Furthermore, it is more preferable that the pitch width of the through holes is in the range of 1.3 to 1.8 mm. Moreover, it is preferable that the aperture ratio (ratio of the total area of the opening part of the through-hole which occupies for the whole area) of one counter electrode is 50 to 90%. Furthermore, the line width of the fine metal wire is preferably 0.2 mm or less, more preferably 0.1 mm or less, and further preferably 0.05 mm or less. This is because a thin metal wire having a line width of 0.2 mm or more is obstructive. In addition, although a lower limit is not specifically limited, 0.01 mm or more is preferable from the need of ensuring sufficient continuity of a thin wire | line.

  On the other hand, the metal mesh (2) can be obtained by a method conventionally employed when making a metal mesh for screen printing, and a fine metal wire having a diameter in the range of 0.01 mm to 0.1 mm can be woven. .

FIG. 3 is a cross-sectional view of an ECD cell when the metal mesh (2) is used as a transparent flexible electrode as a counter electrode. The metal mesh (2) is a counter electrode comprising a metal mesh 20 carrying an electrode active material between two functional electrodes (a flexible electrode in which a transparent conductive thin film 17 and an electrochromic thin film 18 are laminated on the transparent plastic substrate 1). 5 is a structure in which a solid or quasi-solid electrolyte layer 19 is suspended. In the embodiment of FIG. 3, the electrode active material is substantially distributed over the entire surface of the metal mesh.

(Metal mesh material)
The metal material used for the metal mesh is not particularly limited as long as it has a sheet resistance value of 10Ω / □ or less, and more preferably 1Ω / □ or less. For example, in the case of the metal mesh (1), aluminum (Al), copper (Cu), silver (Ag), titanium (Ti), indium (In), tin (Sn), tungsten (W), stainless steel (SUS) And the like. Among these, aluminum is optimal when it is subjected to micropore processing as in the above-described method for producing the metal mesh (1) because chemical etching is easy and inexpensive. Here, 0.001-0.1 mm is suitable for the thickness of a metal sheet, 0.02-0.08 mm is more suitable, and 0.03-0.05 mm is still more suitable. If the thickness is less than 0.001 mm, the metal may be completely lost by etching. On the other hand, if the thickness is greater than 0.1 mm, the aspect ratio of the surface of the counter electrode is large, so that it is difficult to attach the gel electrolyte membrane to such a counter electrode. That is, a lot of bubbles remain between the gel layer and the counter electrode after the two are attached, which causes some problems in cell performance. On the other hand, in the case of the metal mesh (2), metals such as tungsten (W) and stainless steel (SUS) having excellent mechanical strength are suitable. The diameter of the fine metal wire used is basically the same as the above range.

  In both the metal mesh (1) and (2), the shape of the hole in the metal mesh is not particularly limited, and is, for example, a square, a rectangle, a hexagon, a triangle, a circle, or an ellipse. As a result of the formation of a large number of such holes on the metal sheet, a large number of fine metal wires intersect vertically, horizontally, diagonally, etc., and the intersections are electrically connected to each other, and a conductive network of a metal mesh is constructed. . In various hole shapes, a hexagonal shape (honeycomb shape) is optimal for providing a large number of regular holes in a metal sheet with a larger hole area ratio. For example, by providing a large number of hexagonal holes on a metal sheet, a homogeneous conductive network 12 as shown in FIG. 1 can be made. The electrodes made in this way work complementarily even if breaks occur in some parts of the conductive network.

By providing a large number of holes on the counter-electrode metal sheet as described above, not only such a complementary conductive network is constructed, but also high light transmission and high conductivity can be achieved side by side. That is, since the light transmittance as a counter electrode is determined by the size and number of holes on the metal sheet, it is important to make such a complementary conductive network that the light transmittance is in the range of 50 to 90%. How to optimize the size of the opening. Incidentally, the light transmittance of the counter electrode is determined as the aperture ratio of the through hole as shown in Table 1 with the line width d, the pitch width W, and the pitch lengths L ₁ and L ₂ as functions.

  Here, the size of one opening is defined by the pitch width, and the performance (for example, response speed) of the element is influenced by the pitch width. In other words, when the pitch width increases beyond a certain range, the functional electrode does not operate uniformly over the entire surface. On the other hand, since the aperture ratio decreases as the pitch width decreases, there is an appropriate range for the pitch width. That is, in the case of the translucent flexible light control device of the present invention, the pitch width is preferably in the range of 1.0 to 2.0 mm, and more preferably in the range of 1.3 to 1.8 mm. Is more preferable. When evaluating the optimum size of the opening in terms of device performance, it can be discussed based on the pitch width (particularly its upper limit) and the aperture ratio (particularly its lower limit). However, it can be said that a pitch width of 1.8 mm or less and an aperture ratio of 50% or more are preferable in terms of performance of the ECD element.

(Transparent flexible plastic substrate)
The material of the transparent flexible plastic substrate is not particularly limited as long as it is a plastic substrate having optical transparency and flexibility. The thickness, surface area, shape, and other characteristics are arbitrary and are appropriately specified according to the purpose. Here, it refers to a flexible plastic sheet having a visible part transmittance of 80% or more and a maximum bending angle of 45 degrees or more that can be bent without breaking. Generally, the thickness is in the range of about 0.05 to 0.5 mm. Moreover, as such a material, a material having heat resistance, chemical resistance and weather resistance is desirable. For example, polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polysulfone, cellulose triacetate, polycarbonate, polyimide, polyetherimide, polyethersulfone, polystyrene, polymethylpentene, Polycycloolefin and other thermoplastic resins can be exemplified.

(Metal mesh coating layer)
When an electrode active material is supported on a metal mesh, a material suitable for device performance is selected from various redox active compounds. It is necessary to select the most suitable one from the viewpoints of electrochemical compatibility with the electrochromic agent used for the functional electrode (for example, the difference in redox potential between the two), the tint of the colored state, the method of loading on the electrode surface, etc. .

  When a metal mesh is made from an aluminum metal sheet by the method for producing the metal mesh (1), since aluminum corrodes easily, it is also important that the coating layer of the metal fine wire has an anticorrosive function. As a method of forming such a corrosion prevention layer, for example, a method of forming a passive layer (aluminum oxide) on the surface by anodizing aluminum is well known. Furthermore, if a redox active compound is deposited thereon, the element can be driven more smoothly without corroding the aluminum used as the counter electrode substrate material. As such a redox active compound, for example, an organic or organometallic compound, or a second metal having a redox potential on the plus side of aluminum can be cited.

  First, the organic or organometallic compound used as the redox active compound will be described. The redox active compound here is a general term for electrochemically active compounds that can accept electrons or holes. Such redox active materials have at least two oxidation and reduction states that can be altered electrochemically arbitrarily and reversibly. By placing such a redox active compound on the counter electrode, the drive voltage when driving the cell can be further reduced, and the cycle performance (life) can be improved. Examples of such redox active compounds include organic or organometallic compounds having electron-accepting or electron-donating groups represented by ferrocene, hydroquinone, quinone, catechol, viologen, phenothiazine, nicotinamide and the like. Such a compound can be easily immobilized on the surface of a metal sheet or electrode by a coating method by introducing it into the skeleton of the organic polymer through a covalent bond.

An electrochromic agent can also be applied as the redox active compound used here. For example, if the electrochromic agent used for the functional electrode is an oxidation-type coloring material (or reduction-type coloring material), another electrochromic agent used for the counter electrode is a reduction-type coloring material (or oxidation-type coloring material). By selecting, coloring and decoloring can be caused simultaneously on the surfaces of both electrodes. Such a double color development type ECD is published in the literature (K. Honda et al. J. Electrochem. Soc., 135, 3151, 1988), in which a combination system of PB or its analog and WO ₃ is used. It has been broken. By using such a double color development type ECD, the corrosion of the metal used as the electrode is prevented and at the same time the electrochromic efficiency is improved.

  Next, the second metal used as the redox active compound will be described. In order for the second metal to be oxidized in place of aluminum as the electrode wiring material, it is essential that its redox potential is on the plus side of that of aluminum. Furthermore, in order to reduce the driving voltage of the cell, the redox potential is +0.7 Vvs. SCE ~ -0.7Vvs. It is preferably in the range of SCE. Examples of such a second metal include Ag, Cu, Ni and the like.

Such a second metal can be deposited on the Al metal sheet in the following manner;
(A) A method in which a second metal (Ag, Cu, Ni, etc.) is plated directly on the Al surface or on the Al surface after Zn is underplated, or
(B) A method of plating inside an aluminum oxide nanopore provided by anodizing the Al surface (see FIG. 4); the method (B) has a larger surface area of the counter electrode covered with the second metal And more advantageous than method (A). FIG. 5 shows a conceptual diagram of the nanoporous structure produced in this way. Here, the second metal 16 is deposited inside the nanopore 15 of the aluminum oxide layer 14 formed by anodizing the surface of the Al fine metal wire 12 on the plastic substrate 11. The second metal 16 protrudes not only inside the nanopores of the aluminum oxide layer 14 but also outside.

  By depositing the second metal on the thin metal wire, not only the drive voltage of the ECD cell is lowered, but also the corrosion of the fine metal wire itself can be prevented. If such a second metal is used as a thin metal wire for the counter electrode, it is oxidized (ie, corroded) as the ECD cell is driven, so that the conductive network provided on the counter electrode is everywhere. Destroyed, causing fatal damage to the cell.

  When the “second metal” as described above is used as the redox active compound, a metal ion is generated with an oxidation reaction on the counter electrode. The metal ions generated in this manner diffuse into the electrolyte layer and reach the functional electrode, where they react with the electrochromic agent to cause reverse electron transfer. That is, the cell self-discharges, causing an undesirable electrochromism. In order to prevent such self-discharge, it is necessary to suppress diffusion of metal ions generated at the counter electrode. As a method for that purpose, for example, it is conceivable to coat a chelating agent having an action of capturing metal ions on the second metal. In particular, a polymer chelating agent is suitable because it can be easily coated on the electrode surface by a coating method. If it is difficult to apply the chelating agent directly to the electrode surface, the chelating agent can be added to the electrolyte layer. Examples of such polymer-type chelating agents include (a) a fluorine-based cation exchange resin such as Nafion (manufactured by DuPont, trademark), (b) polymethacrylic acid, polyvinyl sulfonic acid, polystyrene sulfonic acid, and the like. Vinyl polymer having an acid-dissociable group, (c) a polymer having a basic group such as polyallylamine, polyethyleneimine, polyvinylpyridine, polyvinylimidazole, or (d) a polymer compound having other chelating group (for example, On the other hand, acrylic polymers having a 2-hydroxybenzophenone skeleton manufactured by the company, ULS-633L, ULS-635L, etc.) can be exemplified.

  In the method of manufacturing the metal mesh (2), there is no concern about metal corrosion when SUS is used as the metal material. Therefore, it is necessary to take measures to prevent Al metal corrosion as in the method of manufacturing the metal mesh (1). There is no. However, it is possible to apply the same redox active compound as the electrode active material supported on the fine metal wire.

(The nature of the counter electrode)
The visible light transmittance of the counter electrode of the present invention is 50% or more, preferably 60% to 95%, more preferably 70% to 95%. Although the maximum value of the transmittance is determined by the aperture ratio provided in the metal sheet on the counter electrode and the material of the transmissive flexible plastic substrate, it is considered to be 90 to 95% in practice. Here, the “visible light transmittance” described in this specification is a spectroscope (manufactured by StellarNet, a compact spectroscope EPP2000C-UV-VIS type, a light source is a small halogen lamp, and a condenser is a quartz collimator lens. ) Is used to denote the transmittance of the electrode sample measured at a wavelength of 700 nm in an open system. The sheet resistance value of the counter electrode is preferably 10Ω / □ or less, more preferably 1Ω / □ or less. Here, the “sheet resistance value” in the present specification represents a value measured using a four-terminal resistance value measuring instrument.

《Functional electrode》
The functional electrode used in combination with the counter electrode of the present invention is an electrode having a function such that the light transmittance or reflectance is changed by applying electricity. An example of such a functional electrode is an electrode in which an electrochromic layer is deposited on an ITO / PET electrode substrate.

The electrochromic layer is formed by depositing an electrochromic agent on an electrode substrate by a coating method, an electrodeposition method, a vapor deposition method or the like. For example, (A) reductive coloring materials such as WO ₃ , MoO ₃ , V ₂ O ₅ , Nb ₂ O ₅ , viologens, phthalates, phenanthroline iron complexes, and (B) NiO, Cr ₂ O ₃ , Examples thereof include oxidative coloring materials such as MnO ₂ , CoO, IrO ₂ , Prussian blue, polyaniline, phenothiazines, diphenylamines, and styryls.

≪Electrolyte layer≫
The electrolyte layer of the present invention is not particularly limited, but is selected from the group consisting of (A) liquid type, (B) solid type, and (C) gel (pseudo solid) type, for example. Here, the ion conductive material suppresses side reactions caused by redox-active impurities and moisture contained in a trace amount as much as possible, and there is no freezing in a low temperature environment or solvent evaporation in a high temperature environment, In order to proceed the electrochromic reaction smoothly, it is required to efficiently carry ions from one electrode to the other electrode.

The liquid electrolyte (A) is composed of a solvent and a salt. Examples of the solvent used include propylene carbonate (PC), ethylene carbonate (EC), sulfolane, γ-butyrolactone, dimethylformamide (DMF), and dimethyl. Mention may be made of sulfoxide (DMSO), tetrahydrofuran (THF), dimethoxyethane, 3-methoxypropionitrile and similar polar organic solvents, or mixtures thereof. The supporting salt used is (I) an alkali metal salt (NaCl, KCl, LiClO ₄ , LiI, KPF ₆ etc.) or (II) a quaternary ammonium salt (tetrabutylammonium chloride, butylpyridinium iodide, iodine 1-vinyl-3-methylimidazolium, etc.). Note that a group of quaternized imidazole compounds called ionic liquids are not only used as solvents, but also effective as supporting salts and have a specific property that they do not evaporate. It is also suitable as an ECD electrolyte.

  The solid electrolyte (B) is composed of a polymer matrix resin and a supporting salt. Examples of the polymer matrix resin used include main chain polymers (I) such as polyethylene oxide (PEO) and polysiloxane. ) And a side chain polymer (II) such as polymethacrylate having PEO in the side chain. The supporting salt added to this is the same as the supporting salt of the liquid electrolyte (A).

  The gel (pseudo-solid) type electrolyte (C) is composed of a crosslinked polymer matrix resin, a salt and a solvent, and the crosslinked polymer is crosslinked by a method such as heating and irradiation with a monomer together with a crosslinking agent. Can be synthesized. Examples of such a monomer include acrylamide, (meth) acrylate having a PEO side chain, and other vinyl compounds.

Of these various electrolytes, gel-type electrolytes are optimal for the following reasons:
(1) A cell can be easily produced by laminating a gel electrolyte sheet between two flexible electrodes by a roll-to-roll method.
(2) The risk of solvent leakage from the gel electrolyte layer is low.
(3) Since the ionic conductivity of the gel electrolyte layer can be set closer to that of the liquid type, the response speed of the device can be increased.
(4) Since it is possible to easily add additives (for example, redox agents such as ferrocyanate, ferrocene, heptyl viologen, chelating agents, etc.) to the gel layer, the cell performance can be adjusted. It is relatively easy.

Manufacturing method of translucent flexible dimming element (counter electrode manufacturing method)
The counter electrode according to this embodiment is a highly translucent and highly conductive electrode in which an electrode active material is supported on the surface of a metal mesh having a pitch width of 1.8 mm or more and an aperture ratio of 50% or more. As described above, the metal mesh (1) is obtained by attaching a metal sheet to a substrate, and providing a number of through holes on the metal sheet and patterning it into a mesh shape, and the metal mesh (2) is obtained by spinning a fine metal wire. Manufactured by a method of weaving and processing into a mesh.

Here, the manufacturing method of the metal mesh (1) includes the following steps 1 to 4;
Step 1: A process of attaching an aluminum sheet to a transparent plastic substrate,
Step 2: providing a through hole in the aluminum sheet to which the transparent plastic substrate is attached in Step 1;
Step 3: A step of providing nanopores on the aluminum surface provided with the through holes in Step 2, and Step 4: A step of supporting an electrode active material inside the nanopores.

On the other hand, the manufacturing method of a metal mesh (2) has the following steps 1-3;
Step 1: a process of supporting an electrode active material on a metal mesh,
Step 2: The step of suspending the metal mesh carrying the electrode active material in Step 1 in the solid type or quasi-solid type electrolyte layer, and Step 3: Step 2 of the two electrolyte layers having the metal mesh suspended therein Step of sandwiching between the functional electrodes.
Hereinafter, each step will be described in detail.
In step 1, a metal sheet is laminated on a transparent plastic substrate. As the method, for example, a method of laminating by the dry laminating method using an adhesive described in JP-A-2006-4306 can be applied.

  As step 2, for example, a large number of through holes can be formed in a metal sheet attached on a plastic substrate according to a photolithography technique. Here, a positive or negative photoresist having etching resistance (acid or alkaline solution) is coated on a metal sheet, and then a large number of through holes are formed in the metal sheet by applying a normal photolithography process and chemical etching. To form. It is also possible to provide through holes in the metal sheet by other techniques such as gravure printing and laser ablation.

In step 3, a nanoporous aluminum oxide thin film is formed by anodic oxidation in order to provide a corrosion prevention layer on the thin metal wire (Al) obtained in step 2. FIG. 4 schematically shows the nanopore structure of the aluminum oxide layer thus obtained: there are innumerable holes of regular size in the order of nanometers, and the side walls of the holes are made of insulating aluminum oxide. The bottom of each hole is connected to the surface of the metal aluminum via a very thin aluminum oxide dense layer (called a barrier layer) of about several tens of millimeters. Since electrons can pass through this thin barrier layer, this nanoporous cavity can be used as a field for electrochemical reactions. The pore size and properties of the aluminum oxide layer can be controlled by selecting the type of electrolyte used for the anodization of Al as follows. Examples of the electrolytic solution used here include acidic solutions such as sulfuric acid, oxalic acid, chromic acid, and phosphoric acid, and alkaline solutions. The pore size can also be controlled by the reaction conditions for anodizing Al. Generally, the hole diameter is in the range of 120-330 mm. Of the above five types of electrolytes, sulfuric acid is most commonly used. The reason is that the aluminum oxide layer has excellent properties such as transparency, corrosion resistance, wear resistance, and low cost because the process consumes less power. When processing an Al metal fine wire formed on a PET substrate, the sample is dipped in 50% nitric acid for 30 seconds to be degreased, and then washed with a sufficient amount of water and methanol and then dried. After the sample surface is cleaned in this way, it is immersed in 10-20 w / v% sulfuric acid, the liquid temperature is kept constant at 20 +/− 2 ° C., and a voltage of 10-20 V is applied to adjust the current density. set to 0.8~1.5A / dm ^2. The film thickness of the aluminum oxide increases as the total amount of current passed increases; in general, the time is 1 to 3 minutes.

  In step 4, an electrode active material is supported inside the nanopores of the aluminum oxide layer. The electrode active material used in the present invention includes the following two candidates: (A) a redox-active organic substance or organometallic compound, and (B) a redox potential of +0.7 V vs. SCE ~ -0.7Vvs. A second metal in the range of SCE.

  Among the options of (A), in this case, an electrolytic polymerization film such as polyaniline, polypyrrole, or polythiophene can be cited as the best one. The reason is that if the electrolytic polymerization method is used, the electrode active material can be deposited relatively easily by the electrolytic method inside the nanopores of the aluminum oxide layer.

  Said (B) can also be carry | supported inside nanopore comparatively easily by the plating method. For example, when Ag is plated inside the nanopore of an aluminum oxide layer formed by anodizing Al for 1.5A in 20% sulfuric acid for 2 minutes, 7-9wt% potassium cyanide, 2-3wt% cyanide When a current of 3 A is passed in a plating bath containing silver for different times, a counter electrode having a surface state as shown in FIG. 6 can be produced. The photograph on the left side of the figure is for the case where the energization amount is 40C, and the photograph on the right side is for the case of 80C. What appears to be fine particles on the surface are silver fine particles protruding from the inside of the nanopore of the aluminum oxide layer to the surface. Thus, the Ag coverage of the entire electrode surface is increased by increasing the energization amount. Further, the sheet resistance value on the electrode surface tends to decrease as the Ag coverage increases, and in the present invention, the Ag coverage is required to be at least 30%.

On the other hand, the manufacturing method of a metal mesh (2) has the following steps 1-3;
Step 1: a process of supporting an electrode active material on a metal mesh,
Step 2: a step of suspending the metal mesh carrying the electrode active material obtained in Step 1 in a solid or quasi-solid type electrolyte layer, and Step 3: two electrolyte layers obtained in Step 2 A process of sandwiching between functional electrodes.

Hereinafter, each step will be described in detail.
As Step 1, the electrode active material carried on the metal mesh is basically the same as that used in Step 4 in the method for producing the metal mesh (1). However, in this case, a corrosion-resistant metal (for example, SUS) can be used as the metal constituting the metal mesh, so that the electrode active material can be directly supported on the metal surface.

  As the step 2, there are several approaches as a means for floating the metal mesh in the solid or quasi-solid electrolyte layer as follows.

(A) When the matrix of the solid type or quasi-solid type electrolyte used here is a crosslinked organic polymer, a monomer or a prepolymer, a crosslinking agent and / or a polymerization initiator, a solvent, other additives (for example, A method of heating, irradiating, etc. after placing a polymerization composition solution comprising a thickener, etc., floating a metal mesh from above so that the solution penetrates into the mesh, and further placing a cover layer thereon The monomer is cross-linked and solidified. As the monomer or prepolymer used here, the above-mentioned monomer or oligomer thereof (low polymerization degree polymer) can be applied.

(B) A low molecular oil gelling agent can be used as a matrix of the solid type or quasi-solid type electrolyte used here. Low molecular weight oil gelling agent is a three-dimensional structure formed by relatively weak non-covalent forces such as electrostatic interaction, hydrogen bond, van der Waals force by external stimuli such as heating, cooling, irradiation, and stirring. A compound having the ability to take a liquid such as an organic solvent or oil into a network structure (gel) and make it quasi-solid. Examples of such oil gelling agents include 2,4-dibenzylidene-D-sorbitol, N-lauroyl-L-glutamic acid-bis-n-butyramide, benzoylgluconamide derivatives, O-methyl-4,6-benzylidene- D-galactose, 2,3-O-isopropylideneglycerin aldehyde derivative, L-isoleucine derivative, L-valyl-L-valine derivative, diamide and diurea derivative synthesized from trans-1,2-cyclohexanediamine, double-headed amino acid Derivatives, L-lysine derivatives and the like. Among these gelling agents, an optimum material can be selected from the viewpoints of mechanical strength, electrical characteristics, light transmittance, weather resistance, cost, and the like. When a gelling agent is used, steps such as heating and irradiation as required in the above case (A) are not required for solidification. This is because when the metal mesh is suspended, the temperature can be once raised to a fluid state, and then the gelling agent can be solidified by lowering the temperature of the gelling agent to a melting point or lower.

(C) It has been reported in Japanese Patent Application Laid-Open No. 2004-178885 and the like that a liquid electrolyte can be quasi-solidified by adding fine particles having a large number of hydroxyl groups on the surface thereof such as silica and titania. Such a method can also be applied to the present invention. For example, the electrolyte can be solidified in a gel state by adding about 20 to 40 wt% of such transparent solid fine particles to the electrolyte solution.

  As step 3, when the functional electrode is attached to the surface of the solid-type or quasi-solid-type electrolyte, it is important not to introduce bubbles between the functional electrode surface and the electrolyte layer. This is because the presence of bubbles inside the cell increases the electrical resistance at the interface between the functional electrode and the electrolyte layer. In the case of mass production, since the electrolyte layer and the functional electrode are pasted by a roll-to-roll method, defects due to such bubbles can be minimized. In addition, in the step 2, when producing a solid type or quasi-solid type electrolyte in which a metal mesh is suspended, if two functional electrodes are used for the substrate and the cover layer, the two electrodes can be obtained without the risk of bubble generation as described above. Can be directly attached to the electrolyte layer.

Manufacturing method of translucent flexible dimming element (whole)
Next, the manufacturing method of the whole translucent flexible light control element which concerns on this best form is demonstrated. Since the method for manufacturing the counter electrode has been described above, first, the method for manufacturing the functional electrode will be described. The manufacturing method of the functional electrode is as follows. That is, an electrochromic thin film can be deposited on the surface of a transparent conductive electrode according to several methods as follows:
(A) depositing a conductive polymer such as polyaniline, polythiophene, or polypyrrole by electrolytic polymerization;
(B) depositing a soluble polymer by spin coating;
(C) Prussian blue (PB) or its analog is deposited according to the method described in the paper (K. Itaya et al., J. Am. Chem. Soc., 1982, 104, 4767).
(D) Paper for PB ink (T. Kawamoto, et al., Jpn. J. Appl. Phys., 2007, 46, L945; ibid.,
2008, 47, 1242), or (E) an electrochromic metal oxide (for example, WO ₃ etc.) is deposited by sputtering.

  When the gel type is used as the electrolyte layer, the functional electrode and the counter electrode can be attached to the gel surface by utilizing the adhesiveness of the gel. In particular, when the counter electrode is floating in the gel layer, a double color cell can be constructed by attaching two functional electrodes to the gel. Such a cell has the advantage that the contrast can be doubled compared to other normal single color cells.

  The translucent flexible light control device of the present invention can be applied to a window for the purpose of blocking the heat rays of sunlight. These windows are called “smart windows” and can be installed on houses, cars, trains, airplanes, or other windows of various sizes, and are used to save energy, especially in the summer. Is done. The translucent flexible light control element of the present invention is used for other applications, for example, an office partition, a home curtain as an interior design, or a display.

(Prototype of counter electrode: Examples 1-6)
An aluminum sheet (thickness: about 0.05 mm) is adhered to a polyethylene terephthalate (PET) substrate (thickness: about 0.05 mm) by a dry laminating method, and a vinyl chloride-vinyl acetate resist ink is gravure printed on the aluminum. The circuit pattern as shown in FIG. 1 was applied, and the entire substrate was immersed in a ferric chloride aqueous solution to dissolve and remove the aluminum portion not covered with the resist. Thereafter, the resist was removed with a solvent to produce a transparent flexible electrode having through holes of a predetermined shape. Here, the through-holes were formed in a honeycomb shape, and the through-holes having different pitch widths were manufactured. Table 2 shows the size and aperture ratio of each through hole. In addition, various AC in Table 2 and A'-C 'are the length (unit: mm) of the part shown in FIG.

(Transmittance measurement)
About the transparent conductive flexible electrode of Prototype Examples 1-6, the transmittance | permeability of each 700 nm light was measured. The results are shown in Table 3. The “actual value” in the table is a value measured according to the measurement method described in the “visible light transmittance”, and the “calculated value” is the aperture ratio in Table 2 (however, rounded off after the decimal point).

(Resistance measurement)
The sheet resistance value of the aluminum part of the transparent conductive flexible electrode (PET substrate with aluminum mesh) obtained as described above was 0.5Ω / □ or less.

Examples 1 to 2 and Comparative Examples 1 to 2 The PET substrate with an aluminum mesh (hereinafter referred to as Al / PET) used in the trial production examples 1 and 3 of the translucent flexible dimming element is used as it is (Comparative Example 1). And Comparative Example 2) or surface modification (Examples 1 and 2) were used as counter electrodes. Before use, Al / PET was immersed in 50% nitric acid for 30 seconds, then washed with water and replaced with methanol and dried. As the surface modification of Example 1, anodic oxidation and silver plating were performed under the following conditions; anodic oxidation was conducted in 20% sulfuric acid at a constant current value of 1.5 A for 120 seconds, and then potassium cyanide: 7 to 9 wt. %, Silver cyanide: Silver plating was carried out by applying electricity at a constant current value of 3 A for 30 seconds in a plating bath of 2 to 3 wt%. In Example 2, a chelate polymer (ULS-635L, manufactured by one company) was further applied to the surface of the silver / plated Al / PET electrode substrate produced in Example 1 to form a film having a thickness of about 0.1 mm. A laminate of thick chelate layers was used as the counter electrode.

  As the functional electrode, a functional electrode in which PB (Prussian blue) is electrodeposited on an ITO-deposited PET substrate (hereinafter referred to as ITO / PET), a sheet resistance value of 25 to 60Ω / □, and a transmittance of 80 to 85% at 700 nm ( Hereinafter, PB / ITO / PET) was prepared; as PB electrodeposition conditions, ITO / PET (surface area, 55 cm × 90 cm) was immersed in an electrolytic solution having the following composition, and the constant current mode (5 mA) was performed. : Ferrous chloride: 2.75 g / L, potassium ferricyanide: 4.25 g / L, hydrochloric acid: 0.85 ml / L. The PB electrodeposition amount (film thickness) is defined by the energization amount. Actually, a PB / ITO / PET electrode having a transmittance at 700 nm of 2 to 6% was used.

As an electrolyte layer sandwiched between the above two electrodes, a gel sheet prepared as follows was used; acryloylmorpholine as a monomer: 30.2 wt%, oxyethylene dimethacrylate as a cross-linking agent: 0.5 wt%, as a solvent A gel compound composition comprising propylene carbonate: 61.3 wt% and KPF ₆ : 8 wt% as a supporting salt is polymerized to form transparent ions having a film thickness of 0.3 mm and an ionic conductivity of approximately 2.0 × 10 ⁻⁴ S / cm. A conductive gel sheet was obtained.

  Table 4 shows the surface treatment conditions of the counter electrodes of Examples 1-2 and Comparative Examples 1-2 and the performance of the ECD cell. Comparative Example 1 uses Al / PET without surface modification (aluminum wire pitch width W = 1.0), Comparative Example 2 uses aluminum wire pitch width W = 1.6, and Example 1 uses Comparative Example 2. Example 2 shows the respective ECD characteristics when a chelate polymer (ULS-635L manufactured by one company) is laminated on the Ag surface of the counter electrode of Example 1 when the surface of the aluminum wire is anodized and silver-plated. It was.

Summarizing the characteristics of each cell shown in Table 4, the following conclusion is reached:
(1) As shown in Comparative Example 1, when the cell was constructed without the surface modification of aluminum, the driving voltage of the ECD cell was +/− 3.5 V at the time of color disappearance. At this time, the transmittance was 12% during coloring and 29% during decoloring, and a very large contrast was not obtained.

(2) As shown in Comparative Example 2, the transmittance at the time of decoloration increased from 29% to 55% by increasing the aluminum pitch width by 1.6 times. Thus, the transmittance at the time of coloring was not influenced by the pitch width. On the other hand, the contrast of the cell of Comparative Example 2 (the rate of change in transmittance during color erasing) was significantly increased as compared to the cell of Comparative Example 1. Note that the response time and the drive voltage were comparable to those of Comparative Example 1.

(3) As shown in Example 1, by modifying the aluminum surface, the driving voltage (absolute value) at the time of fading was reduced from 3.5 V to 1.5 V, which was half or less. This is thought to be due to the difference between the redox potential of aluminum and that of silver. That is, it is considered that the redox potential of Ag used as the electrode active material has a value closer to that of the electrochromic agent (PB) than that of the metal (Al) constituting the electrode wiring.

(4) Examples 1 and 2 having a corrosion prevention layer showed better repeated driving performance than Comparative Examples 1 and 2. That is, when repeating the color erasing with the setting of the driving voltage and response time shown in Table 4, in Comparative Examples 1 and 2, performance degradation was recognized in about 100 cycles, whereas Example 1 In 2 and 2, the performance degradation was slight even when the number of cycles was 1,000 times or more.

(5) In Example 2 in which the corrosion prevention layer includes a chelate layer, the memory property was superior to Comparative Examples 1 and 2 and Example 1. That is, by applying a chelate polymer to the Ag surface, it is possible to prevent the diffusion of silver ions generated by the oxidation of Ag to the functional electrode, resulting in a transmittance retention time (memory performance) in an open circuit state in a decolored state It was observed that the length was several times longer than when no chelate polymer was applied.

Example 3 Trial Manufacture of Translucent Flexible Light Control Element After anodizing an Al / PET substrate (W = 1.6 mm) according to the above method, it was immersed in a sulfamine nickel plating bath having the following composition, and 50 ° C. In a constant current mode, cathode electrolysis was performed for 3 minutes, the total energization amount was set to 165 C, and Ni was plated inside the nanopores of the anodized aluminum: nickel plating bath composition; Ni (NH ₂ SO ₃ ) ₂ -4H ₂ O : 40 w / v%, NiCl: 1.5 w / v%, H ₃ BO ₃ : 4 w / v%. Using the electrode thus prepared as a counter electrode and the PB / ITO / PET electrode prepared by the above method as a functional electrode, these two electrodes were attached to the gel sheet prepared by the above method to prepare a cell. The ECD characteristics of the obtained cell were as follows; that is, the response time at the time of decoloring when the driving voltage was set to +/− 2 V was about 60 seconds. The transmittance at 700 nm was 5 to 9% during coloring and 45 to 50% during decoloring.

Example 4 Trial Manufacture of Translucent Flexible Dimming Element An ethyl acetate solution of a chelate polymer (ULS-635L, manufactured by one company) was applied to the surface of the Ni / Plated Al substrate produced in Example 3 with a film thickness. A cell was fabricated under the same conditions as in Example 3 except that the electrode coated to have a thickness of about 0.17 mm was used as the counter electrode. The ECD characteristics of the obtained cell were almost the same as the results of Example 3 with respect to the driving voltage and response time, but a significant difference was observed in the memory characteristics. That is, as a result of examining the relationship between the transmittance and the holding time in the open circuit state in the decolored state, when the ULS-635L is not applied (in the case of Example 3), the transmittance attenuates with time and When the time to reach 80% of the initial value (hereinafter referred to as “memory retention time”) was about 60 minutes, memory was retained when ULS-635L was applied (in the case of Example 4). The time was about 300 minutes.

  The reason why the memory characteristics are improved by applying ULS-635L in this way is considered as follows. That is, since ULS-635L is an acrylic polymer having a 2-hydroxybenzophenone skeleton in the side chain, it has a function of capturing metal ions (chelating action), and as a result, it is considered that such an effect was expressed. Ni on the counter electrode itself reduces and oxidizes in response to the oxidation and reduction of the PB of the functional electrode, but the nickel ions generated by the oxidation dissolve into the electrolyte gel layer and diffuse to the functional electrode It is thought that the cell self-discharges and the memory function is deteriorated. Since this diffusion is prevented by capturing the nickel ions generated at the counter electrode by ULS-635L, it is considered that the memory retention time in Example 4 was increased.

Example 5 Trial Manufacture of Translucent Flexible Light Control Element Polyethylene glycol (PEG) system containing SUS metal mesh (line width 30 μm, aperture ratio 75%), propylene carbonate (PC) as solvent, and KPF ₆ as supporting salt A counter electrode suspended in the cross-linked gel was prepared as follows. That is, first, nickel plating was performed on the SUS surface by the method described in Example 3. Next, a polymer (PEG-Im) having quaternized imidazole groups introduced at both ends of PEG was synthesized according to the literature (JY Kim, et al., J. Power Sources, 2008, 175, 692-697) This was dissolved with KPF ₆ to have the following composition: PEG-Im: 30 wt%, KPF ₆ : 8 wt%, PC: 62 wt%. The polymer solution thus obtained was cast on a PB / ITO / PET electrode, placed so that the solution penetrates into the mesh from above and the SUS mesh floats in the solution, and another gel solution is placed on the gel surface. A functional electrode, PB / ITO / PET, was attached to produce a cell. The ECD characteristics of the obtained cell were not significantly different in driving voltage and response speed compared with the cell produced in Example 3, but significant in contrast (difference in transmittance during decoloring). The difference was recognized.

1: Transparent flexible electrode,
11: Transparent flexible plastic substrate,
12: Metal thin wire,
13: a through hole provided in the metal sheet,
14: Aluminum oxide layer,
15: Aluminum oxide nanopore,
16: second metal deposited inside the nanopore of aluminum oxide,
17: Transparent conductive thin film,
18: Electrochromic thin film,
19: solid or quasi-solid electrolyte layer,
20: a metal mesh carrying an electrode active material,
W: pitch width,
L ₁ , L ₂ : pitch length,
d: line width of the fine metal wire,
A, A ′, B, B ′, C, C ′: length of each part of one honeycomb pattern

Claims (14)

  Using a metal mesh surface with a pitch width of 1.8 mm or less and an aperture ratio of 50% or more as a counter electrode, the light transmittance is reversibly changed by applying electricity to the counter electrode. A light-transmitting flexible dimming element comprising a functional electrode and an electrolyte layer having a surface to be treated.   The translucent flexible light control element according to claim 1, wherein the metal mesh is attached to a transparent flexible plastic substrate.   The material of the metal mesh is aluminum, and a material in which an electrode active material is supported inside a microporous structure of an aluminum oxide nanoporous structure formed by anodizing the aluminum surface is used as a counter electrode. The translucent flexible light control element as described.   The electrode active material has a redox agent and a redox potential of +0.7 Vvs. -0.7V vs. from SCE. 4. The translucent flexible light control element according to claim 3, which is at least one compound selected from the group consisting of metals in the range of SCE.   The redox potential is +0.7 Vvs. -0.7V vs. from SCE. The translucent flexible light control element according to claim 4, further comprising a coating layer made of a chelating agent on a metal in the range of SCE.   The translucent flexible light control element according to claim 4, wherein the redox agent is Prussian blue or an analog thereof. Next steps (1) to (4):
(1) Step 1: a process of attaching an aluminum sheet to a transparent plastic substrate,
(2) Step 2: a step of providing a through hole in the aluminum sheet to which the transparent plastic substrate is attached in Step 1;
(3) Step 3: a step of providing nanopores on the aluminum surface provided with through holes in Step 2, and (4) Step 4: a step of supporting an electrode active material inside the nanopores:
The manufacturing method of the translucent type flexible light control element of any one of Claim 2 to 6 containing these.   The electrode active material has a redox potential of +0.7 Vvs. -0.7V vs. from SCE. The method for producing a translucent flexible light control element according to claim 7, wherein the metal is in the range of SCE. Following the step 4, the following step (5):
(5) Step 5: Redox potential is +0.7 Vvs. -0.7V vs. from SCE. The manufacturing method of the translucent flexible light control element of Claim 8 with which the process of coat | covering a chelating agent on the metal in the range of SCE is performed.   The method for manufacturing a translucent flexible light control element according to claim 7, wherein the electrode active material is Prussian blue or an analog thereof.   2. The translucent flexible light control element according to claim 1, wherein the metal mesh is placed in a solid or quasi-solid electrolyte layer, and the electrolyte layer is sandwiched between two functional electrodes. .   The translucent flexible light control element according to claim 11, wherein a material of the metal mesh is one or more metals selected from the group consisting of tungsten and stainless steel.   The translucent flexible light control element according to claim 11, wherein the electrode active material is applied to the entire surface of the metal mesh. Next steps (1) to (3);
(1) Step 1: a process of supporting an electrode active material on a metal mesh,
(2) Step 2: Step of floating the metal mesh carrying the electrode active material in Step 1 in the solid or quasi-solid type electrolyte layer, and (3) Step 3: Step 2 of floating the metal mesh in The sandwiched electrolyte layer between two functional electrodes:
The manufacturing method of the translucent flexible light control element of Claim 11 containing this.