Method for manufacturing a laminate, a composition, and an electrochromic device

Abstract

The present invention provides a laminate (300) for production of an electrochromic device, said laminate (300) comprising an electrolyte film (103), a first support film (10) laminated to one surface of the electrolyte film (103), and a second support film (20) laminated to the other surface of the electrolyte film (103), wherein the electrolyte film (103) contains a polymer, an electrolyte, and a first solvent, and has an average thickness of 10-500 μm, and the viscosity at 23°C of a polymer solution obtained by dissolving 2.0 g of the polymer in 50 mL of tetrahydrofuran is 10-50 mPa･s. The polymer may include at least one polymer selected from the group consisting of polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene oxide (PEO), poly(vinylidene fluoride-co-hexafluoroisopropyl) (PVdF-co-PHFP), polypropylene carbonate (PPC), polyvinyl acetal, and polyacrylonitrile (PAN).

Description

Technical Field

[0001] The present invention relates to a laminate, a composition, and a method for manufacturing an electrochromic device. More specifically, the present invention relates to a laminate for manufacturing an electrochromic device, a composition for forming an electrolyte film contained in the laminate, and a method for manufacturing an electrochromic device using the laminate.

Background Art

[0002] A metallosupramolecular polymer is a coordination polymer obtained by complex formation of a metal ion and an organic ligand, and is colored by charge transfer absorption of the metal complex part. The present inventors have previously clarified that a metallosupramolecular polymer exhibits reversible electrochromic characteristics by electrochemical oxidation-reduction of a metal ion (see, for example, Patent Documents 1 and 2).

[0003] Since a metallosupramolecular polymer can be formed into a film on an electrode substrate by coating under the atmosphere, a resin substrate having flexibility can be used without requiring heat resistance for the substrate. Thereby, it is possible to produce a flexible electrochromic device. For example, an electrochromic device is expected as a next-generation glass that contributes to reducing the energy consumption for air conditioning in indoor spaces such as offices by effectively dimming sunlight. If the electrochromic device is flexible, attachment (adhesion) and detachment (peeling) to / from an existing window can be easily performed as needed.

[0004] An electrochromic device controls the coloring and discoloring of an electrochromic layer by arranging a layer containing a metallosupramolecular polymer (electrochromic layer) between a pair of electrode substrates and applying a voltage. In order to promote the charge transfer between the electrode and the electrochromic layer, an electrolyte layer is provided between the electrode and the electrochromic layer. The electrolyte layer is formed, for example, by applying a fluid gel electrolyte or a liquid electrolyte solution at the manufacturing site of the electrochromic device. For this reason, in order to prevent liquid leakage to the surroundings, it was necessary to surround the periphery of the electrolyte application area with a sealing material.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the adhesiveness and sealing property of the sealing material are greatly reduced when the base material is replaced with a resin base material having flexibility, and the risk of liquid leakage increases. This point has been a problem in realizing a flexible electrochromic device. Also, from the viewpoint of mass-producing electrochromic devices, a method capable of forming the electrolyte layer more simply and efficiently has been demanded.

[0007] Therefore, one object of the present invention is to provide a laminate in which an electrolyte layer (electrolyte film) can be formed more simply and efficiently in the manufacture of an electrochromic device.

Means for Solving the Problems

[0008] As a result of intensive studies, the present inventors have found that the above problems can be achieved by the following configuration.

[0009] [1] A laminate for manufacturing an electrochromic device, comprising an electrolyte film, a first support film laminated on one surface of the electrolyte film, and a second support film laminated on the other surface of the electrolyte film, wherein the electrolyte film contains a polymer, an electrolyte, and a plasticizer as a first solvent, has an average film thickness of 10 μm to 500 μm, and the viscosity of a polymer solution obtained by dissolving 2.0 g of the polymer in 50 mL of tetrahydrofuran at 23°C is 10 mPa·s to 50 mPa·s. [2] The laminate according to [1], wherein the polymer contains at least one selected from the group consisting of polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene oxide (PEO), poly(vinylidene fluoride - co - hexafluoroisopropyl) (PVdF - co - PHFP), polypropylene carbonate (PPC), polyvinyl acetal, and polyacrylonitrile (PAN). [3] The laminate according to [2], wherein the polymer contains polymethyl methacrylate (PMMA). [4] The laminate according to any one of [1] to [3], wherein the electrolyte contains at least one selected from the group consisting of LiClO4, LiBF4, LiAsF6, LiPF6, LiCF3SO3, LiCF3COO, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), LiCH3COO, tetrabutylammonium perchlorate, tetraethylammonium perchlorate, KCl, NaClO3, NaCl, NaBF4, NaSCN, KBF4, Mg(ClO4)2, and Mg(BF4)2. [5] The laminate according to any one of [1] to [4], wherein the plasticizer as the first solvent contains at least one selected from the group consisting of propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, γ - butyrolactone, succinonitrile, dimethyl sulfoxide, N - methyl - 2 - pyrrolidone, and ionic liquids. [6] The laminate according to any one of [1] to [5], wherein the first support film has a larger film thickness than the second support film. [7] The laminate according to any one of [1] to [6], wherein the surface of the first support film and / or the surface of the second support film in contact with the electrolyte film is formed of a fluororesin or a silicone resin. [8] A composition for forming the electrolyte film contained in the laminate according to any one of [1] to [7], the composition comprising the polymer, the electrolyte, a plasticizer as the first solvent, and a second solvent, and having a viscosity of 250 mPa·s to 7400 mPa·s at 23°C. [9] The composition according to [8], wherein the viscosity of the composition is 250 mPa·s to 300 mPa·s.

[10] The composition according to [8] or [9], wherein the second solvent contains at least one selected from the group consisting of acetonitrile, acetone, ethyl acetate, and tetrahydrofuran.

[11] A method for manufacturing an electrochromic device, comprising: preparing a laminate according to any one of [1] to [7]; forming an electrochromic layer containing a metallosupramolecular polymer in which metal cations and organic ligands are alternately connected by coordination bonds on a first electrode substrate; forming a counter electrode layer on a second electrode substrate; peeling the second support film from the laminate to expose the other surface of the electrolyte film; bonding the exposed other surface of the electrolyte film to the counter electrode layer on the second electrode substrate; peeling the first support film from the electrolyte film bonded to the counter electrode layer to expose one surface of the electrolyte film; and bonding the exposed one surface of the electrolyte film to the electrochromic layer on the first electrode substrate.

[12] The method for manufacturing an electrochromic device according to

[11] , wherein the counter electrode layer contains a metal hexacyanoferrate represented by the formula: M(II)3[Fe(III)CN6]2 (wherein M is at least one selected from Fe, Ni, and Zn). [Advantages of the Invention]

[0010] The laminate of the present invention can form an electrolyte layer (electrolyte film) more simply and efficiently in the manufacture of an electrochromic device. Further, even when a resin substrate having flexibility is employed for an electrode substrate in an electrochromic device, by manufacturing the electrochromic device using the laminate of the present invention, the risk of liquid leakage of the electrolyte to the surroundings can be almost eliminated.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0012] Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on representative embodiments of the present invention, but the present invention is not limited to such embodiments. Within the scope of the present invention, or as long as the desired effects are achieved, elements of a part of one specific embodiment described below and elements of a part of another specific embodiment can be arbitrarily combined. In this specification, a numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value.

[0013] [Laminate] As shown in FIG. 1, a laminate 300 according to an embodiment of the present invention includes an electrolyte film 103, a first support film 10 laminated on one surface 103a of the electrolyte film 103, and a second support film 20 laminated on the other surface 103b of the electrolyte film 103. The laminate 300 is used for manufacturing an electrochromic device (for example, the electrochromic device 100 in FIG. 2 described later). Here, although not particularly limited, it is preferable that the first support film 10 is directly laminated on one surface 103a of the electrolyte film 103, and / or it is preferable that the second support film 20 is directly laminated on the other surface 103b of the electrolyte film 103.

[0014] The electrolyte film 103 contains a polymer, an electrolyte (supporting electrolyte), and a plasticizer (first solvent). In the electrolyte film 103, the electrolyte is dissolved in the plasticizer and ionized, and is dispersed in the polymer (matrix). The plasticizer enters between the polymer molecular chains, weakens the intermolecular force, and plasticizes the polymer (imparts flexibility). Then, the electrolyte ions move together with the plasticizer between the polymer molecular chains, enabling charge transfer in the electrolyte film 103.

[0015] The polymer contained in the electrolyte film 103 is not particularly limited and may be appropriately selected within the range where the desired effect is achieved. Examples of the polymer include polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene oxide (PEO), poly(vinylidene fluoride-co-hexafluoroisopropyl) (PVdF-co-PHFP), polypropylene carbonate (PPC), polyvinyl acetal, and polyacrylonitrile (PAN). Among them, polymethyl methacrylate (PMMA) is preferable in terms of high transparency, and polycarbonate (PC) is preferable in terms of high heat resistance. These polymers may be used alone or in combination of two or more.

[0016] The polymer contained in the electrolyte film 103 is characterized in that the viscosity of a polymer solution prepared by dissolving 2.0 g of the polymer in 50 mL of tetrahydrofuran at 23°C is 10 mPa·s to 50 mPa·s. The viscosity of the polymer solution depends on the molecular weight of the polymer. The higher the molecular weight, the higher the viscosity of the polymer solution tends to be, and the lower the molecular weight, the lower the viscosity of the polymer solution tends to be. The viscosity of a polymer solution prepared by dissolving 2.0 g of the polymer in 50 mL of tetrahydrofuran at 23°C may preferably be 15 mPa·s to 45 mPa·s, more preferably 20 mPa·s to 40 mPa·s, even more preferably 20 mPa·s to 35 mPa·s, and most preferably 25 mPa·s to 30 mPa·s.

[0017] When the viscosity of the polymer solution is within the above range, a laminate 300 with both good film-forming properties and transfer properties can be obtained. In particular, when the viscosity of the polymer solution is equal to or higher than the lower limit of the above range, for example, the occurrence of fine irregularities (orange peel) and uneven drying on the surface of the electrolyte film 103 can be prevented, and phenomena such as crystallization and precipitation of the contained electrolyte can be suppressed, enabling a more uniform film to be obtained (improvement of film-forming properties). Also, although details will be described later, in the manufacture of the electrochromic device 100, the electrolyte film 103 in a state where the first support film 10 and the second support film 20 are removed (peeled off) is transferred onto the electrode substrate (for example, on the counter electrode layer 105 on the second electrode substrate 104) (see FIGS. 5A and 5B described later). At this time, since the viscosity of the polymer solution is equal to or higher than the lower limit value of the above range, a part of the electrolyte film 103 does not collapse during peeling, and it is completely peeled off from the first support film 10 and / or the second support film 20. As a result, no defective part occurs in the transferred electrolyte film 103, no wrinkles occur in the transferred electrolyte film 103, and no bubbles occur between the transferred electrolyte film 103 and the adjacent layer, and peeling can be successfully performed (improvement in transferability). By using such an electrochromic device with the electrolyte film 103 having improved film-forming properties and / or transferability, sufficient electrochromic characteristics can be obtained (improvement in device characteristics). On the other hand, in the process of forming the electrolyte film 103, it is usually necessary to dissolve a polymer in a solvent (second solvent). However, since the viscosity of the polymer solution is equal to or lower than the upper limit value of the above range, a sufficient amount of the polymer can be dissolved in the solvent. As a result, an electrolyte film 103 containing a desired amount of the polymer can be formed.

[0018] <UNK> The electrolyte is not particularly limited as long as it is an ionizable compound (e.g., a salt), and examples thereof include LiClO4, LiBF4, LiAsF6, LiPF6, LiCF3SO3, LiCF3COO, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), LiCH3COO, tetrabutylammonium perchlorate, tetraethylammonium perchlorate, KCl, NaClO3, NaCl, NaBF4, NaSCN, KBF4, Mg(ClO4)2, and Mg(BF4)2. Among them, lithium perchlorate (LiClO4) is preferred in view of ionic conductivity and ease of handling. These electrolytes effectively function as counter anions of the metallosupramolecular polymer contained in the electrochromic layer (e.g., layer 102 in FIG. 2). That is, the electrolyte layer has a function (charge compensation function) of compensating for the charge with respect to the change in valence accompanying the redox reaction of the metal ions in the metallosupramolecular polymer in the electrochromic layer. Note that the electrolyte may be used alone or in combination of two or more.

[0019] The plasticizer (first solvent) is liquid at room temperature. Examples of the plasticizer include propylene carbonate (PC), ethylene carbonate, dimethyl carbonate, diethyl carbonate, γ-butyrolactone, succinonitrile, dimethyl sulfoxide, N-methyl-2-pyrrolidone, and ionic liquids. The ionic liquid includes, for example, a combination of at least one anion selected from the group consisting of tetrafluoroborate, hexafluorophosphate, bis(trifluoromethanesulfonyl)imide, and bis(pentafluoroethylsulfonyl)imide, and at least one cation selected from the group consisting of imidazolium, pyrrolidinium, and tetraalkylammonium. Among them, propylene carbonate (PC) is preferred as the plasticizer from the viewpoints of price and safety. Note that the plasticizer may be used alone or in combination of two or more. By using the plasticizer, not only the application of the coating liquid for forming the electrolyte film is facilitated, but also the crystallization of the above-described polymer (polymer matrix) constituting the electrolyte film 103 is suppressed, and a decrease in response speed can be prevented.

[0020] In the electrolyte film 103, the compounding amount of each component or the ratio between the components is not particularly limited and can be appropriately adjusted within the range that exhibits the desired effect. The compounding amount of each component or the ratio between the components may be, for example, within the following ranges: the total compounding amount (A + B + C) of the polymer (A), the electrolyte (B), and the plasticizer (C) is 50 to 100% by mass based on 100% by mass of the entire electrolyte film, and the compounding amount of the polymer (A) is 10% to 80% by mass; alternatively, the compounding mass ratio (B / A) of the electrolyte (B) to the polymer (A) is 0.1 to 2, and / or the compounding mass ratio (C / A) of the plasticizer (C) to the polymer (A) is 0.5 to 5.

[0021] The electrolyte film 103 may be composed only of a polymer, an electrolyte, and a plasticizer, or may contain other optional components such as a solvent (for example, the second solvent described later) different from the plasticizer (the first solvent) within the range that exhibits the desired effect. Further, the electrolyte film 103 may contain a colorant as another component in order to improve the contrast of the electrochromic device in which it is used.

[0022] The electrolyte film 103 can be formed by removing the solvent (the second solvent) from the coating film 30 of a composition (coating solution) containing a polymer, an electrolyte, a plasticizer (the first solvent), and a solvent (the second solvent) (see FIGS. 3 and 4 described later). By manufacturing an electrochromic device using the laminate 300 including such an electrolyte film 103, the solvent removal step at the manufacturing site of the electrochromic device can be omitted, and the manufacturing of the electrochromic device can be made more efficient. The content of the solvent (the second solvent) in the electrolyte film 103 may be, for example, 50% by mass or less or 40% by mass or less.

[0023] The thickness (average film thickness) d103 of the electrolyte film 103 is 10 μm to 500 μm, and preferably may be 50 μm to 100 μm. The average film thickness here can be determined as the average of the thicknesses at at least any 10 locations. When the thickness of the electrolyte film 103 is equal to or greater than the lower limit value of the above range, the handleability is improved. On the other hand, when it is equal to or less than the upper limit value of the above range, it becomes easier to remove the solvent (second solvent) from the electrolyte film 103. Incidentally, the average film thickness d103 of the electrolyte film 103 can be measured, for example, by the measurement method used in the examples.

[0024] The first support film 10 and the second support film 20 are not particularly limited as long as they are flexible resin films. For example, polyethylene terephthalate (PET), polypropylene (PP), or the like can be used. The first support film 10 and the second support film 20 are peeled off from the electrolyte film 103 at the manufacturing site of the electrochromic device. Therefore, from the viewpoint of ease of peeling, the surface 10a of the first support film 10 and / or the surface 20a of the second support film 20 that is in contact with the electrolyte film 103 is preferably formed to contain a release agent such as a fluororesin or a silicone resin. Therefore, for example, the first support film 10 and / or the second support film 20 are preferably entirely formed of a release agent such as a fluororesin or a silicone resin, or contain a release agent such as a fluororesin layer or a silicone resin layer on the surface. Further, the first support film 10 and the second support film 20 may be made of the same material or different materials.

[0025] The first support film 10 and the second support film 20 may have the same thickness (d1 = d2), or the first support film 10 may be thicker than the second support film 20 (d1 > d2). The thickness of each of the first support film 10 and the second support film 20 here refers to the average thickness and can be obtained as the average of the thicknesses at any at least 10 locations. When the first support film 10 is thicker than the second support film 20, for example, it has the following advantages. In the manufacture of an electrochromic device, first, the second support film 20 is peeled off from the electrolyte film 103 to expose the other surface 103b of the electrolyte film 103, and the surface 103b is bonded to the counter electrode layer 105 on the second electrode substrate 104. At the time of this bonding, it is easier to handle and the working efficiency is improved when the first support film 10 supporting the electrolyte film 103 is thicker. Also, since a thinner film tends to be peelable with a smaller force, it is preferable that the second support film 20 to be peeled first is thinner. Further, as shown in FIG. 4, in the manufacture of the laminate 300, first, the electrolyte film 103 is formed on the first support film 10, and then the second support film is laminated. Also in the manufacture of the laminate 300, the handling property and the working efficiency are improved when the first support film 10 is thicker.

[0026] For example, the thickness d1 of the first support film 10 may be 1 to 10 times, or 1 to 5 times the thickness d2 of the second support film (d1 / d2 = 1 to 10, or 1 to 5). Also, the thickness d1 of the first support film 10 may be, for example, 10 μm to 500 μm, or 30 μm to 200 μm, and / or the thickness d2 of the second support film 20 may be, for example, 10 μm to 300 μm, or 30 μm to 200 μm. If any one of the thicknesses d1, d2, and the ratio (d2 / d1), or preferably two or three of them, are within the above ranges, the working efficiency is further improved in the manufacture of the electrochromic device and in the manufacture of the laminate 300.

[0027] Further, the peeling load (P1) when peeling the first support film 10 from the electrolyte film 103 is preferably greater than the peeling load (P2) when peeling the second support film 20 from the electrolyte film 103 (P1 > P2). As described above, in the manufacture of the electrochromic device, only the second support film 20 is peeled first, leaving the first support film 10. At this time, if the peeling loads are in the above-mentioned magnitude relationship (P1 > P2), it is easy to peel only the second support film 20 while leaving the first support film 10. Further, also in the manufacture of the laminate 300, if the peeling load (P2) of the first support film 10 is relatively large (that is, difficult to peel), it is easy to stably hold the electrolyte film 103 on the first support film 10, improving the working efficiency. The peeling load can be adjusted, for example, by the materials, configurations, thicknesses, etc. of the first and second support films 10 and 20. The peeling load of the first support film 10 may be, for example, 100 to 300 mN / 50 mm width, and / or the peeling load of the second support film 20 may be, for example, 10 to 50 mN / 50 mm width.

[0028] [Manufacturing method of laminate] The manufacturing method of the laminate 300 is not particularly limited. With reference to FIGS. 3 and 4, an example of the manufacturing method of the laminate 300 will be described below.

[0029] The manufacturing method of the laminate 300 may include, for example, the following steps shown in FIG. 3: Step S1: Preparation of a coating solution (composition for forming an electrolyte film), Step S2: Coating of the coating solution onto the first support film 10, Step S3: Removal of the solvent (second solvent) from the coating film, and Step S4: Lamination of the second support film 20.

[0030] First, a coating solution (composition for forming an electrolyte film) containing a polymer, an electrolyte, a plasticizer (first solvent), and a solvent (second solvent) is prepared (step S1 in FIG. 3). The polymer, electrolyte, and plasticizer can use the aspects already described. The solvent (second solvent) may be simply referred to as "solvent" hereinafter.

[0031] The solvent (second solvent) is a solvent different from the plasticizer (first solvent), and is not particularly limited as long as it can dissolve the polymer and the electrolyte. It is preferable that the solvent has a lower boiling point than the plasticizer (first solvent) so that it can be easily removed in step S3. Examples of the solvent (second solvent) include acetonitrile, acetone, ethyl acetate, and tetrahydrofuran. Among them, acetonitrile is preferable from the viewpoint of the solubility of the resin. The solvent may be used alone or in combination of two or more.

[0032] The coating solution may be composed only of the polymer, the electrolyte, the plasticizer, and the solvent, or may contain other optional components such as a colorant within a range where a desired effect is achieved.

[0033] The viscosity of the coating solution (composition for forming an electrolyte film) at 23°C may be, for example, 250 mPa·s to 7400 mPa·s, or 250 to 300 mPa·s. If the viscosity of the coating solution is within the above range, coating becomes easy and the film-forming property is also improved. In particular, when the viscosity of the coating solution at 23°C is 250 to 300 mPa·s, the adhesiveness (stickiness) of the obtained electrolyte film 103 can be suppressed low and it is easy to handle.

[0034] The blending amount of each component in the coating solution is not particularly limited, and may be appropriately adjusted so that the concentration of the coating solution at 23°C is within the above range. The blending amount (concentration) of each component in the coating solution may be, for example, in the following ranges. Assuming the total coating solution is 100% by mass, the blending amount of the polymer: 2 to 20% by mass, the blending amount of the electrolyte: 1 to 10% by mass, the blending amount of the plasticizer (first solvent): 5 to 50% by mass, and the blending amount of the solvent (second solvent): 50 to 90% by mass. Also, the mass ratio (B / A) of the electrolyte (B) to the polymer (A) and / or the mass ratio (C / A) of the plasticizer (C) to the polymer (A) may be the same as each ratio in the above-described electrolyte film 103.

[0035] The method for preparing the coating solution is not particularly limited, and a polymer, an electrolyte, a plasticizer, a solvent, and, if necessary, other components (optional components) may be mixed and prepared in a uniform manner by a known method. The mixing order is not particularly limited. For example, first, (1) the polymer (e.g., powder) is dissolved in a mixed solution of the solvent and the plasticizer, and (2) the electrolyte and the optional components are added to the obtained polymer solution and further mixed (e.g., stirred). According to the above procedure, a uniform coating solution can be efficiently prepared.

[0036] Next, the coating solution is applied to the surface 10a of the first support film 10 (step S2 in FIG. 3) to form a coating film 30 (FIG. 4). The coating method is not particularly limited, and for example, a doctor blade, a bar coater, etc. can be used. The film thickness of the coating film 30 may be appropriately adjusted so that the film thickness d103 of the final electrolyte film 103 becomes the above-mentioned predetermined thickness. By applying the coating solution to the first support film 10 having a greater thickness than the second support film 20, the advantage of good handleability in subsequent steps can be obtained.

[0037] Next, the solvent (second solvent) is removed from the coating film 30 (step S3 in FIG. 3) to obtain the electrolyte film 103 (FIG. 4). The method for removing the solvent is not particularly limited. For example, the coating film 30 may be dried (the solvent is evaporated) at room temperature, or heating (warming) and blowing may be performed to accelerate drying. The drying temperature of the coating film 30 may be, for example, from room temperature to about 80°C, and the drying time may be, for example, about 5 to 120 minutes. The content of the solvent (second solvent) in the dried electrolyte film 103 may be, for example, 0 mass% or more and 50 mass% or less, or 40 mass% or less.

[0038] Next, the second support film 20 is laminated on the electrolyte film 103 in such a direction that the surface 20a contacts the electrolyte film 103 to obtain a laminate 300 (step S4 in FIG. 3). The obtained laminate may be cut into a desired size.

[0039] The laminate 300 described above can be used in the manufacture of an electrochromic device, thereby enabling the electrolyte layer (electrolyte film) to be formed more simply and efficiently. A manufacturing method according to an embodiment of the electrochromic device will be described below.

[0040] [Manufacturing Method of Electrochromic Device] <Electrochromic Device> First, an electrochromic device that can be manufactured using the laminate 300 will be described. FIG. 2 shows an electrochromic device 100 as an example. The electrochromic device 100 includes a substrate (first electrode substrate 101 including a first electrode) that includes one of a pair of electrodes arranged opposite to each other; an electrochromic layer 102 including a metallosupramolecular polymer disposed on one of the electrodes (first electrode); a substrate (second electrode substrate 104 including a second electrode) that includes the other of the pair of electrodes disposed above the electrochromic layer 102; an electrolyte layer (electrolyte film) 103 disposed between the second electrode substrate 104 and the electrochromic layer 102; and a counter electrode layer 105 disposed between the electrolyte layer 103 and the second electrode substrate 104. The electrolyte layer 103 is composed of the electrolyte film 103 included in the laminate 300. In the electrochromic device 100, the first electrode (101) and the electrochromic layer 102 function as a working electrode. Also, the second electrode (104) and the counter electrode layer 105 function as a counter electrode.

[0041] The operation of the electrochromic device 100 will be described. The first electrode of the first electrode substrate 101 and the second electrode of the second electrode substrate 104 are connected to a power source (not shown), and a predetermined voltage is applied to the electrochromic layer 102, the electrolyte layer 103, and the counter electrode layer 105. Thereby, the oxidation-reduction of the metallosupramolecular polymer in the electrochromic layer 102 can be controlled. More specifically, by applying a predetermined voltage, the oxidation-reduction reaction of the metal cations of the metallosupramolecular polymer in the electrochromic layer 102 can be controlled. As a result, the coloring and decoloring of the electrochromic device can be controlled.

[0042] The above electrochromic device is applicable to a dimming device, a display device (display element), and the like. When the electrochromic device 100 is used as a dimming device, it is preferable that both the first electrode substrate 101 and the second electrode substrate 104 are capable of transmitting external light (transparent or having a high transmittance). Further, when the electrochromic device 100 is used as a display device, at least one of the first electrode substrate 101 and the second electrode substrate 104 may be transparent (or have a high transmittance) to visible light. In the display device, it is preferable that the transparent electrode substrate side is the viewing side.

[0043] <Method for manufacturing an electrochromic device> The manufacturing method of the electrochromic device 100 may include, for example, the following steps shown in FIG. 3: Step S10: Preparation of the laminate 300; Step S20: Forming the electrochromic layer 102 on the first electrode substrate 101; Step S30: Forming the counter electrode layer 105 on the second electrode substrate 104; Step S40: Peeling the second support film 20 from the laminate 300; Step S50: Bonding the other surface 103b of the exposed electrolyte film 103 to the counter electrode layer 105 on the second electrode substrate 104; Step S60: Peeling the first support film 10 from the electrolyte film 103; Step S70: Bonding the one surface 103a of the exposed electrolyte film 103 to the electrochromic layer 102 on the first electrode substrate 101.

[0044] First, prepare the laminate 300 (step S10 in FIG. 3). The laminate 300 may be manufactured, for example, by a manufacturing method including the above steps S1 to S4.

[0045] Next, an electrochromic layer 102 is formed on the first electrode substrate 101 (step S20 in FIG. 3). The first electrode substrate 101 includes a base material and a first electrode formed thereon. Examples of the base material include a glass substrate and a resin substrate, but it is not particularly limited. The manufacturing method using the laminate 300 is particularly suitable when the base material is a flexible resin substrate. Examples of the material of the flexible resin substrate include polyethylene terephthalate (PET), polypropylene (PP), and the like. Further, the thickness of the first electrode substrate 101 is preferably, for example, 10 μm to 500 μm, or 30 μm to 200 μm.

[0046] The first electrode is preferably a transparent conductive film (transparent electrode) made of, for example, an SnO2 film, an In2O3 film, or an ITO (Indium Tin Oxide) film which is a mixture of In2O3 and SnO2. The first electrode may be formed on the base material by a known method.

[0047] When a flexible resin substrate is used for the first electrode substrate 101, in order to improve the handleability, as shown in FIG. 5B, the first electrode substrate 101 may be supported by the first support plate 106. For example, the first electrode substrate 101 is supported by a first support plate (for example, a glass plate) 106 via an adhesive film (not shown), and the electrochromic layer 102 is formed on the first electrode substrate 101 in that state.

[0048] The electrochromic layer 102 includes a metallosupramolecular polymer in which metal cations and organic ligands are alternately connected by coordination bonds. The electrochromic layer 102 may be formed, for example, by the materials and formation methods disclosed in the patents and patent published gazettes listed below. The contents described in the following patents and patent published gazettes are incorporated herein by reference. Japanese Patent No. 5062712 (Patent Document 1), International Publication No. 2019 / 1 77160 (Patent Document 2), Japanese Patent No. 6758729, Japanese Patent No. 6713175.

[0049] The metal cation contained in the metallosupramolecular polymer is preferably a transition metal and / or a lanthanoid metal. Specific examples of the metal include, for example, iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), europium (Eu), terbium (Tb), and the like. The organic ligand preferably contains, for example, a terpyridyl group, a bipyridyl group, a pyridyl group, a phenanthrolyl group, an acetylacetonato group, or a derivative thereof. The metallosupramolecular polymer may be a commercially available product or may be synthesized in-house. Further, the electrochromic layer 102 may further contain a counter anion of the metallosupramolecular polymer. The counter anion is not particularly limited, and examples thereof include acetate ion, phosphate ion, chloride ion, hexafluorophosphate ion, tetrafluoroborate ion, perchlorate ion, triflate ion, polyoxometalate, and the like.

[0050] The method for forming the electrochromic layer 102 is not particularly limited, but typically includes a method of preparing a composition (coating material) containing a solvent and coating it on the first electrode. Examples of the solvent include polar solvents such as methanol and ethanol. Examples of the coating method include spin coating, spray coating, dip coating, and the like. Further, a sheet of the electrochromic layer may be produced and directly attached onto the first electrode. From the viewpoint of easily forming a thin and uniform coating film, spray coating is preferable. Preferred conditions (coating conditions) for spray coating of the electrochromic layer 102 are, for example, as follows. Discharge rate: 0.1 mL / min to 10 mL / min, head speed: 10 mm / sec to 200 mm / sec, coating pitch: 0.1 mm to 5 mm, number of repetitions: 1 to 10 times, coating temperature (stage temperature of the spray coater): room temperature to 80°C.

[0051] On the second electrode substrate 104, a counter electrode layer 105 is formed (step S30 in FIG. 3). The second electrode substrate 104 includes a base material and a second electrode formed thereon. As the base material and the second electrode, the same ones as those of the first electrode substrate 101 described above can be used. When a resin base material having flexibility is used for the second electrode substrate 104, in order to improve the handleability, as shown in FIG. 5A, the second electrode substrate 104 may be supported by a second support plate 107. For example, the second electrode substrate 104 is supported by a second support plate (for example, a glass plate) 107 via an adhesive film (not shown), and the counter electrode layer 105 is formed on the second electrode substrate 104 in that state.

[0052] The counter electrode layer 105 may be formed, for example, by the materials and forming methods disclosed in International Publication No. 2019 / 177160 (Patent Document 2). The content described in Patent Document 2 is incorporated herein by reference. The counter electrode layer 105 is preferably a metal complex-based electrochromic film, and may be, for example, a film of metal hexacyanoferrate (MHCF) represented by the formula: M(II)3[Fe(III)CN6]2 (wherein M is at least one selected from Fe, Ni, and Zn). By combining a counter electrode including a counter electrode layer containing these specific materials with a working electrode including a metallosupramolecular polymer, the electrochromic device 100 can exhibit a sufficiently low driving voltage or operating potential.

[0053] ​The method for forming the counter electrode layer 105 is not particularly limited. Typically, a method of preparing a composition (coating material) containing a solvent, applying it onto the second electrode, and forming the layer can be mentioned. Examples of the solvent include solvents such as water, methanol, and tetrahydrofuran that can dissolve or disperse the counter electrode material. Examples of the coating method include spin coating, spray coating, dip coating, and the like. Also, a sheet of the counter electrode layer may be produced and directly attached onto the second electrode. From the viewpoint of easily forming a thin and uniform coating film, spray coating is preferred. The conditions (coating conditions) for spray coating the counter electrode layer 105 may be the same as the preferred conditions (coating conditions) for spray coating the electrochromic layer 102 described above.

[0054] Next, as shown in FIG. 5A, the second support film 20 is peeled off from the laminate 300 to expose the other surface 103b of the electrolyte film 103 (step S40 in FIG. 3). Then, the exposed other surface 103b of the electrolyte film 103 is bonded to the counter electrode layer 105 on the second electrode substrate 104 (step S50 in FIG. 3). At this time, if the second support film 20 is thinner than the first support film 10 (that is, if the first support film 10 is thicker than the second support film 20), it can be easily peeled off with a smaller force. And even after the second support film 20 is peeled off, the electrolyte film 103 is supported by the relatively thick first support film 10, so it is easy to handle.

[0055] Next, as shown in FIG. 5B, the first support film 10 is peeled off from the electrolyte film 103 to expose one surface 103a of the electrolyte film 103 (step S60 in FIG. 3). Then, the exposed one surface 103a of the electrolyte film 103 is bonded to the electrochromic layer 102 on the first electrode substrate 101 (step S70 in FIG. 3). Thereby, the electrochromic device 100 is obtained.

[0056] As shown in FIG. 5B, when using the first support plate 106 and the second support plate 107, after the bonding process (process S70), the first support plate 106 and the second support plate 107 are separated from the electrochromic device 100. Also, in the separation process of the first support plate 106 and the second support plate 107, separation (bubbles) may occur between the electrolyte film 103 and the electrochromic layer 102 and / or the counter electrode layer 105. Therefore, if necessary, the electrochromic device 100 may be heat-pressed to remove the bubbles (degassing).

[0057] Also, in order to more surely adhere the first electrode substrate 101 and the second electrode substrate 104, an adhesive 108 or the like may be used (see FIG. 6). Thereby, the mechanical strength of the electrochromic device 100 is improved. For example, the areas of the electrolyte film 103, the electrochromic layer 102, and the counter electrode layer 105 are adjusted to be smaller than the areas of the first electrode substrate 101 and the second electrode substrate 104, and the adhesive 108 is provided at the outer edge portion of the electrochromic device 100, and in the bonding process (process S70, see FIG. 3), the first electrode substrate 101 and the second electrode substrate 104 may be adhered. The adhesive 108 may be provided, for example, on the first electrode and the second electrode (for example, ITO film) formed on each of the first electrode substrate 101 and the second electrode substrate 104. The material of the adhesive 108 is not particularly limited, and general-purpose adhesives such as ultraviolet-curable epoxy resins and ultraviolet-curable acrylic adhesives can be used.

[0058] In the method for manufacturing the electrochromic device 100 using the laminate 300 described above, it is not necessary to form the electrolyte layer 103 by coating or the like at the manufacturing site. Therefore, the preparation process of the electrolyte layer paint (fluid gel electrolyte or electrolyte solution), the installation process of the sealing material for preventing the leakage of the electrolyte to the surroundings, the coating process, the drying process, etc. at the manufacturing site can be omitted, and the electrolyte layer can be formed more simply and efficiently. In particular, when a resin base material having flexibility is used for the first electrode substrate 101 and the second electrode substrate 104, the conventional manufacturing method including the coating process has the problem of leakage of the electrolyte layer paint. On the other hand, since at least half to more than half of the solvent (second solvent) has already been removed from the electrolyte film 103 included in the laminate 300, there is no risk of liquid leakage. Thus, the laminate 300 is particularly suitable for manufacturing a flexible electrochromic device using a resin base material having flexibility.

[0059] Also, the laminate 300 is easier to store, manage quality, and transport compared to the conventional paint for forming the electrolyte layer. Furthermore, the manufactured laminate 300 can be cut into a desired size in advance.

[0060] By using the laminate 300 having the above advantages, mass production of electrochromic devices, particularly flexible electrochromic devices, can be carried out more simply and efficiently. Furthermore, since the laminate 300 has flexibility, it is also possible to manufacture (mass produce) the electrochromic device 100 by roll-to-roll using the laminate 300.

Example

[0061] The present invention will be described in more detail based on the following examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0062] [Example 1-1] 1. Preparation of the laminate 300 In this example, a laminate 300 having the configuration shown in FIG. 1 was produced according to the following procedure (see FIGS. 3 and 4).

[0063] (1) Preparation of coating solution (composition for forming electrolyte film) In this example, a coating solution was prepared using polymethyl methacrylate (PMMA) as the polymer, lithium perchlorate (LiClO4) as the electrolyte, propylene carbonate (PC) as the plasticizer (first solvent), and acetonitrile (ACN) as the solvent (second solvent). The viscosity of the polymer solution, in which 2.0 g of PMMA was dissolved in 50 mL of tetrahydrofuran (THF), at 23°C was 28 mPa·s.

[0064] First, 4g of PMMA powder was placed in a 100mL screw tube, and a mixture of 12g of PC and 42g of ACN was poured into it while stirring with a magnetic stirrer, dissolving the PMMA powder in the mixture. 1.8g of LiClO4 was then added and stirred to obtain a transparent coating solution. The viscosity of the resulting coating solution at 23°C was 7380mPa·s.

[0065] (2) Application of coating solution and removal of solvent A commercially available PET film with a silicone resin coating layer (manufactured by Nippa Corporation, product number: J2, thickness: 50 μm, peel load: 140 mN / 50 mm width) was used as the first support film 10. A coating liquid was applied to the surface 10a of the first support film 10, on which the silicone resin coating layer was formed, using a doctor blade at a speed of 10 mm / sec to form a coating film 30. The coating film 30 was then dried at room temperature for 120 minutes to remove the solvent (ACN), and an electrolyte membrane 103 was formed.

[0066] (3) Lamination of the second support film 20 As the second support film 20, a PET film with a silicone resin coating layer (manufactured by Nippa Co., Ltd., product number: JOL, thickness: 50 μm, peel load: 30 mN / 50 mm width) was used. The second support film 20 was laminated on the electrolyte film 103 in such a direction that the surface 20a provided with the silicone resin coating layer of the second support film 20 contacted the electrolyte film 103, and the laminate 300 of this example was obtained.

[0067] In addition, the average film thickness of the electrolyte film 103 in the produced laminate 300 was 80 μm. The average film thickness of the electrolyte film 103 was measured at arbitrarily 10 locations using a dial gauge, and the arithmetic mean value thereof was taken.

[0068] 2. Manufacture of electrochromic device 100 In this example, using the produced laminate 300, an electrochromic device 100 having the configuration shown in FIG. 6 was manufactured according to the following procedure (see FIGS. 3, 5A, and 5B).

[0069] (1) Formation of electrochromic layer 102 A metallosupramolecular polymer represented by the following formula (1) (manufactured by Tokyo Chemical Industry Co., Ltd., Poly(Fe-btpyb) Purple: product code P2789) was dissolved in a solvent (methanol) to prepare a metallosupramolecular polymer solution with a concentration of 8.4 mg / mL.

[0070]

Chemical formula

[0071] A first electrode substrate (100 mm in length × 100 mm in width × 150 μm in thickness) 101 with ITO (first electrode) coated on a flexible PET substrate was prepared. The first electrode substrate 101 was supported on a first support plate (glass plate, thickness: 0.7 mm) 106 via an adhesive film (not shown) (see Fig. 5B). Onto the first electrode of the first electrode substrate 101, a prepared metallosupramolecular polymer solution was spray-coated using a spray coater (manufactured by Appiros, API40RD) to form an electrochromic layer 102. The spray coating conditions were as follows: discharge rate: 2 mL / min, head speed: 100 mm / sec, coating pitch: 1 mm, number of repetitions: 2 times, stage temperature: 60°C.

[0072] (2) Formation of the counter electrode layer 105 An aqueous dispersion (concentration: 0.3 mg / mL) of NiHCF (nickel hexacyanoferrate, Ni(II)3[Fe(III)CN6]2), which is a Prussian blue nickel derivative, was prepared. As the second electrode substrate 104, an electrode substrate having the same configuration as the above-described first electrode substrate 101 was prepared and supported on a second support plate (glass plate, thickness: 0.7 mm) 107 via an adhesive film (not shown) (see Fig. 5A). Onto the second electrode of the second electrode substrate 104, the prepared NiHCF aqueous solution was spray-coated using the spray coater used for forming the electrochromic layer 102 to form a counter electrode layer 105. The spray coating conditions were as follows: discharge rate: 1 mL / min, head speed: 100 mm / sec, coating pitch: 1 mm, number of repetitions: 2 times, stage temperature: 80°C.

[0073] (3) Lamination of the electrolyte film 103 and the counter electrode layer 105 First, the laminate 300 was cut to a size of 9.4 cm × 9.2 cm. The second support film 20 was peeled off from the cut laminate 300 to expose the other surface 103b of the electrolyte film 103. Then, the other surface 103b and the counter electrode layer 105 on the second electrode substrate 104 were bonded together (see Fig. 5A). The areas of the electrolyte film 103 and the counter electrode layer 105 were adjusted to be smaller than the area of the second electrode substrate 104. As a result, even after bonding the electrolyte film 103 and the counter electrode layer 105, there is no electrolyte film 103 and counter electrode layer 105 on the surface of the peripheral portion of the outer edge of the second electrode substrate 104, and there is a region where the ITO film (second electrode) on the surface of the second electrode substrate 104 is exposed. An ultraviolet curable acrylic adhesive (manufactured by Kyoritsu Chemical Co., Ltd., XVL-90T3) 108 was applied to this region by printing (the adhesive 108 is not shown in Fig. 5A, see Fig. 6).

[0074] (4) Bonding of the electrolyte film 103 and the electrochromic layer 102 The area of the electrochromic layer 102 was adjusted to be smaller than the area of the first electrode substrate 101. As a result, there is a region where the ITO film (first electrode) on the surface of the first electrode substrate 101 is exposed on the surface of the peripheral portion of the outer edge of the first electrode substrate 101. When bonding the electrolyte film 103 and the electrochromic layer 102, the ultraviolet curable acrylic adhesive 108 applied to the second electrode substrate 104 contacts this region (around the electrochromic layer 102) to form a good adhesive layer (the adhesive 108 is not shown in Fig. 5B, see Fig. 6).

[0075] The first support film 10 was peeled off from the electrolyte film 103, exposing one surface 103a of the electrolyte film 103. Then, the surface 103a was bonded to the electrochromic layer 102 on the first electrode substrate 101 (see Fig. 5B). At the same time, the first electrode substrate 101 and the second electrode substrate 104 were bonded via the adhesive 108. Then, ultraviolet rays were irradiated from the back surfaces of the first electrode substrate 101 and the second electrode substrate 104 to cure the adhesive 108 (the adhesive 108 is not shown in Fig. 5B, see Fig. 6). Next, each of the first support plate 106 and the second support plate 107 was separated from the first electrode substrate 101 and the second electrode substrate 104, obtaining the electrochromic device 100 of this example. In this example, further, the obtained electrochromic device 100 was heat-pressed with a heat laminator to extrude internal bubbles.

[0076] [Examples 1-2 to 1-4] In Examples 1-2 to 1-4, the laminate 300 was produced in the same manner as in Example 1-1, except that the composition of the coating solution (the blending amounts of the respective components) was changed as shown in Table 1. The viscosities of the coating solutions and the average film thicknesses of the obtained electrolyte films in each example are shown in Table 1. In Examples 1-2 to 1-4, further, using the produced laminate 300, the electrochromic device 100 was produced in the same manner as in Example 1-1.

[0077] [Example 2] In Example 2, PMMA with a different molecular weight was used from Examples 1-1 to 1-4. The viscosity at 23 °C of the polymer solution prepared by dissolving 2.0 g of PMMA used in this example in 50 mL of tetrahydrofuran (THF) was 8.4 mPa·s. Otherwise, the laminate 300 was produced in the same manner as in Example 1-1, and then the electrochromic device 100 was manufactured using this laminate 300. The viscosities of the coating solutions and the average film thicknesses of the obtained electrolyte films are shown in Table 1.

[0078] [Evaluation] Regarding Examples 1-1 to 1-4 and 2, the following evaluations were performed. The results are shown in Table 1.

[0079] 1. Film-forming property In the production of the laminates 300 of Examples 1-1 to 1-4 and 2, the film-forming property of the electrolyte film 103 formed on the first support film 10 was evaluated according to the following evaluation criteria. If the comprehensive evaluation result of the film-forming property below is A or B, it can be determined that the film-forming property is good. In the following evaluation criteria, "smoothness" was evaluated by visually observing the surface of the electrolyte film 103. "Adhesiveness" was evaluated by the ease of peeling of the second support film 20 from the electrolyte film 103. The easier the peeling, the smaller the stickiness of the electrolyte film 103, and it was determined that the evaluation of "adhesiveness" was high. In the following evaluation criteria, if the evaluation result of "adhesiveness" is A or B, it can be determined that the fluidity of the electrolyte film 103 is low, the self-supporting property of the electrolyte film 103 as a film is high, and it is easy to handle.

[0080] <Evaluation Criteria for Film-Forming Property> (1) Comprehensive Evaluation Criteria for Film-Forming Property A: The evaluation result of the smoothness described below is G (good), and the evaluation result of the adhesiveness is A. B: The evaluation result of the smoothness described below is G (good), and the evaluation result of the adhesiveness is B. C: Regardless of the evaluation result of the adhesiveness described below, the evaluation result of the smoothness is NG (bad).

[0081] (2) Evaluation Criteria for Smoothness G: In the electrolyte film 103, none of the fine irregularities (peach skin, orange peel) on the surface, uneven drying, and precipitation (crystallization) of the electrolyte are observed. NG: In the electrolyte film 103, any of the fine irregularities (peach skin, orange peel) on the surface, uneven drying, and precipitation (crystallization) of the electrolyte are observed.

[0082] (3) Evaluation Criteria for Adhesiveness A: When the second support film 20 is peeled off, the stickiness is small, and the shape of the electrolyte film 103 can be maintained in an area of 95% or more. B: When the second support film 20 is peeled off, the shape of the electrolyte film 103 can be maintained with an area of 95% or more, but the stickiness is slightly large. C: When the second support film 20 is peeled off, peeling failure occurs in an area exceeding 5%.

[0083] 2. Transferability In the manufacturing process of the electrochromic devices 100 of Examples 1-1 to 1-4 and 2, after the first support film 10 was peeled off from the electrolyte film 103, the electrolyte film 103 transferred onto the counter electrode layer 105 was visually observed, and the transferability of the electrolyte film 103 was evaluated according to the following evaluation criteria. If the evaluation result is A or B, it can be determined that the transferability is good.

[0084] <Evaluation Criteria for Transferability> A: No defects, wrinkles, or bubbles (bubbles between the electrolyte film 103 and the counter electrode layer 105) were observed in the electrolyte film 103. That is, the area of the region where any of the defect portion, wrinkles, and bubbles exist (hereinafter referred to as the "area of the defective region") was 0% of the area of the electrolyte film 103. B: Any of a defect portion, wrinkles, and bubbles was observed in the electrolyte film 103, but the area of the defective region was 10% or less of the area of the electrolyte film 103. C: The area of the defective region exceeded 10% and was 50% or less of the area of the electrolyte film 103. D: The area of the defective region exceeded 50% of the area of the electrolyte film 103.

[0085] 3. Device Characteristics The electrochromic devices 100 fabricated in Examples 1-1 to 1-4 were connected to a DC power supply (1.5 V) to perform a bleaching / coloring operation. As shown in FIG. 7, it was confirmed that the electrochromic device 100 exhibited a color change from purple (potential 0 V, reduced state Fe(II)) to colorless (potential 1.5 V, oxidized state Fe(III)), that is, electrochromic characteristics (EC characteristics). The display states of the devices fabricated in each example were evaluated according to the following evaluation criteria. If the evaluation result is A or B, it can be determined that the device characteristics are good. In the electrochromic device 100, it is presumed that the reason for the existence of a region where the bleaching / coloring operation cannot be confirmed is that there is a region (defective region) where any of a defect, a wrinkle, and a bubble exists in the electrolyte film 103.

[0086] <Evaluation Criteria for Device Characteristics> A: The area of the region where the bleaching / coloring operation was confirmed was 95% or more of the area of the electrochromic device 100. B: The area of the region where the bleaching / coloring operation was confirmed was 80% or more and less than 95% of the area of the electrochromic device 100. C: The area of the region where the bleaching / coloring operation was confirmed was less than 80% of the area of the electrochromic device 100. D: Due to poor transferability of the electrolyte film 103 (transferability evaluation result: D), the assembly of the electrochromic device was impossible ().

[0087]

Table 1

[0088] As shown in Table 1, in Examples 1-1 to 1-4 where the viscosity of the polymer solution obtained by dissolving 2.0 g of the polymer (PMMA) in 50 mL of THF was 28 mPa·s at 23°C, all of the film-forming property, transferability, and device characteristics had good evaluation results. Among them, in Examples 1-2 to 1 where the viscosity of the coating solution ( Composition for forming an electrolyte film) was 250 to 300 mPa·s In Example -4, the film - forming property evaluation result was better (film - forming property evaluation result: A).

[0089] On the other hand, in Example 2 where the viscosity of a polymer solution prepared by dissolving 2.0 g of polymer (PMMA) in 50 mL of THF was less than 10 mPa·s at 23°C, both the film - forming property and the transfer property were poor. Also, since a laminate 300 with sufficient transfer property could not be produced, an electrochromic device 100 could not be produced in Example 2 (device property evaluation result: D). In Example 2, one of the reasons for the low film - forming property is presumably that because the molecular weight of the polymer is small, the viscosity of the coating solution (the composition for forming the electrolyte film) also becomes low, and the drying of the coating film is accelerated. It is speculated. Also, in Example 2, one of the reasons for the low transfer property is presumably that because the molecular weight of the polymer is small, the adhesiveness of the electrolyte film 103 is low, and sufficient adhesion to the counter electrode layer 105 cannot be obtained. For this reason, the peeling of the second support film 20 was not successful.

[0090] [[ID=!4]]Note that the measurement of the polymer viscosity in these examples was carried out as follows. Also, all the numerical values of the polymer viscosity described in this specification and the appended claims are measured by this method. · Viscosity measuring device Brookfield digital viscometer (Model B viscometer) for low viscosity, "LVDVE" (manufactured by AMETEK Brookfield, compliant with JIS Z8803) · Viscosity measurement conditions Probe: LV5, Rotation speed: 60 rpm

Industrial applicability

[0091] By using the above laminate, the electrolyte layer (electrolyte film) of an electrochromic device can be formed more simply and efficiently. Further, even when a resin substrate having flexibility is employed for the electrode substrate in an electrochromic device, by manufacturing the electrochromic device using the laminate of the above embodiment, the risk of liquid leakage of the electrolyte to the surroundings can be almost eliminated. The electrochromic device thus manufactured can be used for various applications such as a dimming glass device and a display device.

Explanation of Signs

[0092] 10 First support film 20 Second support film 30 Coating film 100 Electrochromic device 101 First electrode substrate 102 Electrochromic layer 103 Electrolyte layer (electrolyte film) 104 Second electrode substrate 105 Counter electrode layer 106 First support plate 107 Second support plate 108 Adhesive 300 Laminate

Claims

1. A laminate for manufacturing an electrochromic device, comprising: an electrolyte film, a first support film laminated on one surface of the electrolyte film, and a second support film laminated on the other surface of the electrolyte film, wherein the electrolyte film contains a polymer, an electrolyte, and a plasticizer as a first solvent, and has an average film thickness of 10 μm to 500 μm, and a viscosity of a polymer solution obtained by dissolving 2.0 g of the polymer in 50 mL of tetrahydrofuran at 23°C is 10 mPa·s to 50 mPa·s.

2. The laminate according to claim 1, wherein the polymer contains at least one selected from the group consisting of polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene oxide (PEO), poly(vinylidene fluoride-co-hexafluoroisopropyl) (PVdF-co-PHFP), polypropylene carbonate (PPC), polyvinyl acetal, and polyacrylonitrile (PAN).

3. The laminate according to claim 2, wherein the polymer contains polymethyl methacrylate (PMMA).

4. The electrolyte is LiClO ４ , LiBF ４ , LiAsF ６ , LiPF ６ , LiCF ３ SO ３ , LiCF ３ COO, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), LiCH ３ COO, tetrabutylammonium perchlorate, tetraethylammonium perchlorate, KCl, NaClO ３ , NaCl, NaBF ４ , NaSCN, KBF ４ , Mg(ClO ４ ), ２ , and Mg(BF ４ ), ２ The laminate according to claim 1, comprising at least one selected from the group consisting of.

5. The laminate according to claim 1, wherein the plasticizer as the first solvent contains at least one selected from the group consisting of propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, γ-butyrolactone, succinonitrile, dimethyl sulfoxide, N-methyl-2-pyrrolidone, and ionic liquids.

6. The laminate according to claim 1, wherein the first support film has a greater thickness than the second support film.

7. The laminate according to claim 1, wherein a surface of the first support film and / or a surface of the second support film in contact with the electrolyte film is formed of a fluororesin or a silicone resin.

8. A composition for forming the electrolyte film included in the laminate according to any one of claims 1 to 7, comprising: the polymer, the electrolyte, the plasticizer as the first solvent, and a second solvent, wherein a viscosity of the composition at 23°C is 250 mPa·s to 7400 mPa·s.

9. The composition according to claim 8, wherein the viscosity of the composition is 250 mPa·s to 300 mPa·s.

10. The composition according to claim 8, wherein the second solvent contains at least one selected from the group consisting of acetonitrile, acetone, ethyl acetate, and tetrahydrofuran.

11. A method for manufacturing an electrochromic device, comprising: preparing a laminate according to any one of claims 1 to 7; forming an electrochromic layer containing a metallosupramolecular polymer in which metal cations and organic ligands are alternately connected by coordination bonds on a first electrode substrate; forming a counter electrode layer on a second electrode substrate; peeling a second support film from the laminate to expose the other surface of the electrolyte film; bonding the exposed other surface of the electrolyte film to the counter electrode layer on the second electrode substrate; peeling a first support film from the electrolyte film bonded to the counter electrode layer to expose one surface of the electrolyte film; and bonding the exposed one surface of the electrolyte film to the electrochromic layer on the first electrode substrate.

12. wherein the counter electrode layer has the formula: M(II) 3 [Fe(III)CN ６ ２ (wherein M is at least one selected from Fe, Ni, and Zn), and the method for manufacturing an electrochromic device according to claim 11, which contains a metal hexacyanoferrate.​

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