Laminate, composition, and method for producing 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

Methods for manufacturing laminates, compositions, and electrochromic devices

[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.

[0002] Metallo-supramolecular polymers are coordination polymers obtained by complexing metal ions with organic ligands, and they become colored by charge-transfer absorption of the metal complex moiety. The present inventors have previously demonstrated that metallo-supramolecular polymers exhibit reversible electrochromic properties through electrochemical oxidation-reduction of metal ions (see, for example, Patent Documents 1 and 2).

[0003] Metallo-supramolecular polymers can be applied to electrode substrates in the atmosphere to form films, eliminating the need for heat resistance in the substrate, allowing flexible resin substrates to be used. This allows for the fabrication of flexible electrochromic devices. For example, electrochromic devices are expected to be next-generation glass that can effectively control sunlight, thereby contributing to reducing the energy consumed for air conditioning in indoor spaces such as offices. If electrochromic devices are flexible, they can be easily attached (attached) and removed (peeled) from existing windows as needed.

[0004] Electrochromic devices place a layer containing a metallo-supramolecular polymer (electrochromic layer) between a pair of electrode substrates, and control the coloring and decoloring of the electrochromic layer by applying a voltage. To promote 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 electrochromic device manufacturing site. Therefore, to prevent leakage to the surrounding area, it has been necessary to surround the electrolyte application area with a sealant.

[0005] Patent No. 5062712 International Publication No. 2019 / 177160

[0006] However, the adhesiveness and sealing ability of the sealing material are significantly reduced when the substrate is replaced with a flexible resin substrate, increasing the risk of liquid leakage. This has been a challenge in realizing flexible electrochromic devices. Furthermore, from the perspective of mass production of electrochromic devices, a method for forming the electrolyte layer more simply and efficiently has been desired.

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

[0008] As a result of extensive research, the present inventors have found that the above object 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 side of the electrolyte film; and a second support film laminated on the other side of the electrolyte film, wherein the electrolyte film contains a polymer, an electrolyte, and a plasticizer as a first solvent, and the average film thickness is 10 μm to 500 μm, and a polymer solution obtained by dissolving 2.0 g of the polymer in 50 mL of tetrahydrofuran has a viscosity of 10 mPa·s to 50 mPa·s at 23° C. [2] The laminate according to [1], wherein the polymer comprises 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 electrolyte contains LiClO ４ , LiBF ４ , LiAsF ６ , LiPF ６ , LiCF３ 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[5] The laminate according to any one of [1] to [4], wherein the plasticizer as the first solvent comprises 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 an ionic liquid. [6] The laminate according to any one of [1] to [5], wherein the first support film has a thickness greater than that of 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 membrane 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], comprising the polymer, the electrolyte, a plasticizer as the first solvent, and a second solvent, the composition having a viscosity of 250 mPa·s to 7,400 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 comprises 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 the laminate according to any one of [1] to [7]; forming an electrochromic layer on a first electrode substrate, the electrochromic layer including a metallo-supramolecular polymer formed by alternating linkages of metal cations and organic ligands via coordination bonds; 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 the 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 counter electrode layer has the formula: M(II)3[Fe(III)CN. ６ ] ２

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

[11] , which contains a metal hexacyanoferrate represented by the formula: (wherein M is at least one selected from Fe, Ni, and Zn).

[0010] The laminate of the present invention allows for the simple and efficient formation of an electrolyte layer (electrolyte film) in the manufacture of an electrochromic device. Furthermore, even when a flexible resin substrate is used as an electrode substrate in an electrochromic device, the risk of electrolyte leakage to the surroundings can be almost eliminated by manufacturing the electrochromic device using the laminate of the present invention.

[0011] FIG. 1 is a cross-sectional schematic diagram of a laminate according to one embodiment. FIG. 2 is a cross-sectional schematic diagram of an electrochromic device according to one embodiment. FIG. 3 is a flowchart illustrating a method for manufacturing a laminate according to one embodiment and a method for manufacturing an electrochromic device using the laminate. FIG. 4 is a diagram illustrating a method for manufacturing a laminate according to one embodiment. FIG. 5A is a diagram illustrating a method for manufacturing an electrochromic device according to one embodiment (first half). FIG. 5B is a diagram illustrating a method for manufacturing an electrochromic device according to the embodiment shown in FIG. 5A (second half). FIG. 6 is a cross-sectional schematic diagram of a laminate according to one embodiment (an example in which an adhesive is used). FIG. 7 is a photograph showing the color change due to electrochemical oxidation-reduction of the electrochromic devices produced in Examples 1-1 to 1-4 of the Examples (top: purple, bottom: transparent).

[0012] The present invention will be described in detail below. The following description of the components may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. Within the scope of the present invention or as long as the desired effect is achieved, some elements of a specific embodiment described below can be arbitrarily combined with some elements of another specific embodiment. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0013] 1 , a laminate 300 according to one embodiment of the present invention includes an electrolyte membrane 103, a first support film 10 laminated on one surface 103 a of the electrolyte membrane 103, and a second support film 20 laminated on the other surface 103 b of the electrolyte membrane 103. The laminate 300 is used to manufacture an electrochromic device (e.g., the electrochromic device 100 in FIG. 2 , which will be described later). Although not particularly limited, it is preferable that the first support film 10 be laminated directly on the one surface 103 a of the electrolyte membrane 103, and / or that the second support film 20 be laminated directly on the other surface 103 b of the electrolyte membrane 103.

[0014] The electrolyte membrane 103 contains a polymer, an electrolyte (supporting electrolyte), and a plasticizer (first solvent). In the electrolyte membrane 103, the electrolyte is dissolved in the plasticizer, ionized, and dispersed in the polymer (matrix). The plasticizer penetrates between the polymer molecular chains, weakening the intermolecular forces and plasticizing the polymer (imparting flexibility). Electrolyte ions move between the polymer molecular chains together with the plasticizer, enabling charge transfer within the electrolyte membrane 103.

[0015] The polymer contained in the electrolyte membrane 103 is not particularly limited and may be appropriately selected within a range that achieves the desired effect. 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 these, polymethyl methacrylate (PMMA) is preferred because of its high transparency, and polycarbonate (PC) is preferred because of its high heat resistance. These polymers may be used alone or in combination of two or more.

[0016] The polymer contained in the electrolyte membrane 103 is characterized in that a polymer solution prepared by dissolving 2.0 g of the polymer in 50 mL of tetrahydrofuran has a viscosity of 10 mPa·s to 50 mPa·s at 23°C. The viscosity of the polymer solution depends on the molecular weight of the polymer. The viscosity of the polymer solution tends to increase as the molecular weight increases, and decreases as the molecular weight decreases. The viscosity of a polymer solution prepared by dissolving 2.0 g of the polymer in 50 mL of tetrahydrofuran at 23°C may be preferably 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 excellent film-forming and transferability can be obtained. In particular, when the viscosity of the polymer solution is equal to or greater 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 membrane 103 is prevented, and phenomena such as crystallization and precipitation of the contained electrolyte are suppressed, resulting in a more uniform film (improved film-forming properties). Furthermore, as will be described in detail later, in the manufacture of the electrochromic device 100, the electrolyte membrane 103 in a state in which the first support film 10 and the second support film 20 have been removed (peeled state) is transferred onto an electrode substrate (e.g., onto the counter electrode layer 105 on the second electrode substrate 104) (see FIGS. 5A and 5B described below). In this case, when the viscosity of the polymer solution is equal to or greater than the lower limit of the above range, the electrolyte membrane 103 is completely peeled off from the first support film 10 and / or the second support film 20 without any collapse during peeling. As a result, the transferred electrolyte membrane 103 is not deformed, wrinkled, or has no air bubbles between the transferred electrolyte membrane 103 and its adjacent layers, resulting in successful peeling (improved transferability). An electrochromic device using such an electrolyte membrane 103 with improved film-forming and / or transferability can achieve sufficient electrochromic properties (improved device characteristics). Meanwhile, while the electrolyte membrane 103 typically requires dissolving the polymer in a solvent (second solvent) during its formation, when the viscosity of the polymer solution is equal to or less than the upper limit of the above range, a sufficient amount of polymer can be dissolved in the solvent. As a result, an electrolyte membrane 103 containing a desired amount of polymer can be formed.

[0018] The electrolyte is not particularly limited as long as it is an ionizable compound (e.g., a salt), and examples thereof include LiClO ４ , LiBF ４ , LiAsF ６ , LiPF ６ , LiCF ３ SO ３ , LiCF３ 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 Among these, lithium perchlorate (LiClO) is preferred because of its ionic conductivity and ease of handling. ４ ) is preferred. These electrolytes effectively function as counter anions of the metallo-supramolecular polymer contained in the electrochromic layer (e.g., layer 102 in FIG. 2). That is, the electrolyte layer has a function of compensating for the charge (charge compensation function) with respect to the change in valence accompanying the oxidation-reduction reaction of the metal ions in the metallo-supramolecular polymer in the electrochromic layer. Note that one type of electrolyte may be used alone, or two or more types may be used in combination.

[0019] The plasticizer (first solvent) is liquid at room temperature. Examples of plasticizers include propylene carbonate (PC), ethylene carbonate, dimethyl carbonate, diethyl carbonate, γ-butyrolactone, succinonitrile, dimethyl sulfoxide, N-methyl-2-pyrrolidone, and ionic liquids. Examples of ionic liquids include 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 these, propylene carbonate (PC) is preferred as the plasticizer from the standpoints of cost and safety. Note that one type of plasticizer may be used alone, or two or more types may be used in combination. The use of a plasticizer not only makes it easier to apply the coating liquid for forming the electrolyte film, but also suppresses crystallization of the above-mentioned polymer (polymer matrix) that constitutes the electrolyte film 103, thereby preventing a decrease in response speed.

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

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

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

[0023] The thickness (average thickness) d103 of the electrolyte membrane 103 is 10 μm to 500 μm, and preferably 50 μm to 100 μm. The average thickness here can be determined as the average of thicknesses measured at at least 10 arbitrary locations. When the thickness of the electrolyte membrane 103 is equal to or greater than the lower limit of the above range, handling properties are improved. On the other hand, when the thickness is equal to or less than the upper limit of the above range, removal of the solvent (second solvent) from the electrolyte membrane 103 is facilitated. The average thickness d103 of the electrolyte membrane 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, and examples thereof include polyethylene terephthalate (PET) and polypropylene (PP). The first support film 10 and the second support film 20 are peeled from the electrolyte membrane 103 at the electrochromic device manufacturing site. Therefore, from the viewpoint of ease of peeling, the surface 10 a of the first support film 10 and / or the surface 20 a of the second support film 20, which are in contact with the electrolyte membrane 103, are 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 formed entirely of a release agent such as a fluororesin or a silicone resin, or include a release agent such as a fluororesin layer or a silicone resin layer on the surface. Furthermore, 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 an average thickness and can be determined as the average of thicknesses measured at at least 10 arbitrary locations. When the first support film 10 is thicker than the second support film 20, for example, the following advantages are obtained. In manufacturing an electrochromic device, the second support film 20 is first peeled from the electrolyte film 103 to expose the other surface 103b of the electrolyte film 103, and the surface 103b is then bonded to the counter electrode layer 105 on the second electrode substrate 104. During this bonding, a thicker first support film 10 supporting the electrolyte film 103 is easier to handle and improves work efficiency. Furthermore, because thinner films tend to be peeled off with less force, a thinner second support film 20, which is peeled off first, is preferred. 4, in the production of the laminate 300, the electrolyte membrane 103 is first formed on the first support film 10, and then the second support film is laminated thereon. In the production of the laminate 300, a thicker first support film 10 also improves handling properties and work efficiency.

[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). Furthermore, 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. When any one of the thicknesses d1, d2, and the ratio (d2 / d1), or preferably two or three of these, are within the above ranges, the work efficiency in manufacturing the electrochromic device and the laminate 300 is further improved.

[0027] Furthermore, the peel load (P1) when peeling the first support film 10 from the electrolyte membrane 103 is preferably greater than the peel load (P2) when peeling the second support film 20 from the electrolyte membrane 103 (P1 > P2). As described above, in the manufacture of electrochromic devices, the second support film 20 is peeled first, leaving the first support film 10. At this time, if the peel loads satisfy the above magnitude relationship (P1 > P2), it is easy to peel only the second support film 20, leaving the first support film 10. Furthermore, in the manufacture of the laminate 300, if the peel load (P2) of the first support film 10 is relatively large (i.e., peeling is difficult), it is easy to stably hold the electrolyte membrane 103 on the first support film 10, improving work efficiency. The peel load can be adjusted, for example, by the material, configuration, thickness, etc. of the first and second support films 10 and 20. The peel load of the first support film 10 may be, for example, 100 to 300 mN / 50 mm width, and / or the peel load of the second support film 20 may be, for example, 10 to 50 mN / 50 mm width.

[0028] [Method for Manufacturing Laminate] There is no particular limitation on the method for manufacturing the laminate 300. An example of a method for manufacturing the laminate 300 will be described below with reference to Figs.

[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 liquid (composition for forming an electrolyte film), Step S2: Application of the coating liquid to a first support film 10, Step S3: Removal of a solvent (second solvent) from the coating film, and Step S4: Lamination of a second support film 20.

[0030] First, a coating liquid (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 may be the same as those 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. The solvent preferably 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, and among these, acetonitrile is preferred from the viewpoint of resin solubility. One type of solvent may be used alone, or two or more types may be mixed and used.

[0032] The coating liquid may be composed of only a polymer, an electrolyte, a plasticizer, and a solvent, or may contain other optional components such as a colorant within a range that provides the desired effect.

[0033] The coating liquid (electrolyte film-forming composition) may have a viscosity at 23°C of, for example, 250 mPa·s to 7400 mPa·s, or 250 to 300 mPa·s. When the viscosity of the coating liquid is within the above range, coating is facilitated and film-forming properties are improved. In particular, when the viscosity of the coating liquid at 23°C is 250 to 300 mPa·s, the adhesiveness (stickiness) of the resulting electrolyte film 103 can be kept low, making it easy to handle.

[0034] The 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 falls within the above-mentioned range. The amount (concentration) of each component in the coating solution may be, for example, within the following ranges: When the total amount of the coating solution is taken as 100% by mass, the polymer amount is 2 to 20% by mass, the electrolyte amount is 1 to 10% by mass, the plasticizer (first solvent) amount is 5 to 50% by mass, and the solvent (second solvent) amount is 50 to 90% by mass. 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 the respective ratios in the electrolyte membrane 103 described above.

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

[0036] Next, a coating liquid 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 application method is not particularly limited, and for example, a doctor blade, a bar coater, or the like can be used. The film thickness of the coating film 30 may be appropriately adjusted so that the final film thickness d103 of the electrolyte membrane 103 is the above-mentioned predetermined thickness. Applying the coating liquid to the first support film 10, which is thicker than the second support film 20, has the advantage of providing good handling properties in subsequent processes.

[0037] Next, the solvent (second solvent) is removed from the coating film 30 (step S3 in FIG. 3 ), thereby obtaining an electrolyte membrane 103 ( FIG. 4 ). The method for removing the solvent is not particularly limited, and for example, the coating film 30 may be dried (to evaporate the solvent) at room temperature, or the drying may be accelerated by heating (warming) or blowing air. The drying temperature for 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 electrolyte membrane 103 after drying may be, for example, 0% by mass or more and 50% by mass or less, or 40% by mass or less.

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

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

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

[0041] The operation of the electrochromic device 100 will now 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. This makes it possible to control the oxidation-reduction of the metallo-supramolecular polymer in the electrochromic layer 102. More specifically, by applying a predetermined voltage, it is possible to control the oxidation-reduction reaction of the metal cations of the metallo-supramolecular polymer in the electrochromic layer 102. As a result, it is possible to control the coloring and decoloring of the electrochromic device.

[0042] The electrochromic device can be applied to a light control device, a display device (display element), and the like. When the electrochromic device 100 is used as a light control device, it is preferable that both the first electrode substrate 101 and the second electrode substrate 104 are transparent to external light (or have high transmittance). When the electrochromic device 100 is used as a display device, it is sufficient that at least one of the first electrode substrate 101 and the second electrode substrate 104 is transparent to visible light (or has high transmittance). In a display device, it is preferable that the transparent electrode substrate side is the viewing side.

[0043] <Method for manufacturing electrochromic device> A method for manufacturing the electrochromic device 100 may include, for example, the following steps shown in Figure 3: Step S10: Preparing 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 one surface 103a of the exposed electrolyte film 103 to the electrochromic layer 102 on the first electrode substrate 101.

[0044] First, the laminate 300 is prepared (step S10 in FIG. 3). The laminate 300 may be manufactured by, for example, a manufacturing method including the above-described 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 substrate and a first electrode formed thereon. Examples of the substrate include, but are not limited to, a glass substrate and a resin substrate. The manufacturing method using the laminate 300 is particularly suitable when the substrate is a flexible resin substrate. Examples of materials for the flexible resin substrate include polyethylene terephthalate (PET) and polypropylene (PP). 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, for example, SnO ２ Membrane, In ２ O ３ Membrane or In ２ O ３ and SnO ２ A transparent conductive film (transparent electrode) made of an ITO (Indium Tin Oxide) film, which is a mixture of ITO and ZnO, is preferred. The first electrode may be formed on the substrate by a known method.

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

[0048] The electrochromic layer 102 includes a metallo-supramolecular polymer formed by alternating chains of metal cations and organic ligands via coordinate bonds. The electrochromic layer 102 may be formed using, for example, the materials and formation methods disclosed in the patents and patent publications listed below. The contents of the following patents and patent publications are incorporated herein by reference: Japanese Patent No. 5062712 (Patent Document 1), International Publication No. WO 2019 / 177160 (Patent Document 2), Japanese Patent No. 6758729, and Japanese Patent No. 6713175.

[0049] The metal cation contained in the metallo-supramolecular polymer is preferably a transition metal and / or a lanthanide metal. Specific examples of metals include 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), and terbium (Tb). 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 metallo-supramolecular polymer may be commercially available or may be self-synthesized. The electrochromic layer 102 may further contain a counter anion of the metallo-supramolecular polymer. The counter anion is not particularly limited, and examples thereof include acetate ion, phosphate ion, chloride ion, phosphorus hexafluoride ion, boron tetrafluoride 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 in which a solvent-containing composition (paint) is prepared and applied to the first electrode. Examples of the solvent include polar solvents such as methanol and ethanol. Examples of application methods include spin coating, spray coating, and dip coating. Alternatively, a sheet of the electrochromic layer may be prepared and directly attached to the first electrode. Spray coating is preferred from the viewpoint of easily forming a thin, uniform coating film. Preferred conditions (application conditions) for spray coating 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, Application pitch: 0.1 mm to 5 mm, Number of repetitions: 1 to 10, Application temperature (stage temperature of the spray coater): Room temperature to 80°C.

[0051] A counter electrode layer 105 is formed on the second electrode substrate 104 (step S30 in FIG. 3 ). The second electrode substrate 104 includes a base material and a second electrode formed thereon. The base material and the second electrode may be the same as those of the first electrode substrate 101 described above. When a flexible resin base material is used for the second electrode substrate 104, the second electrode substrate 104 may be supported on a second support plate 107 as shown in FIG. 5A to improve handling. For example, the second electrode substrate 104 is supported on a second support plate (e.g., 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 this state.

[0052] The counter electrode layer 105 may be formed using the materials and forming methods disclosed in, for example, International Publication No. 2019 / 177160 (Patent Document 2). The contents of Patent Document 2 are incorporated herein by reference. The counter electrode layer 105 is preferably a metal complex-based electrochromic film, for example, a metal complex-based electrochromic film represented by the formula: M(II) ３ [Fe(III)CN ６ ] ２ (wherein M is at least one selected from Fe, Ni, and Zn) The combination of a working electrode containing a metallo-supramolecular polymer with a counter electrode containing a counter electrode layer containing these specific materials allows the electrochromic device 100 to exhibit a sufficiently low driving voltage or operating potential.

[0053] The method for forming the counter electrode layer 105 is not particularly limited, but a typical example is a method in which a composition (paint) containing a solvent is prepared and applied to the second electrode. Examples of the solvent include water, methanol, tetrahydrofuran, and other solvents that can dissolve or disperse the counter electrode material. Examples of application methods include spin coating, spray coating, and dip coating. Alternatively, a sheet of the counter electrode layer may be prepared and directly attached to the second electrode. Spray coating is preferred from the viewpoint of easily forming a thin, uniform coating film. The conditions (application conditions) for spray coating the counter electrode layer 105 may be the same as the preferred conditions (application 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 ). The exposed other surface 103b of the electrolyte film 103 is then 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 (i.e., if the first support film 10 is thicker than the second support film 20), it can be easily peeled off with less force. Furthermore, even after the second support film 20 is peeled off, the electrolyte film 103 is supported by the relatively thick first support film 10, making it 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). The exposed surface 103a of the electrolyte film 103 is then bonded to the electrochromic layer 102 on the first electrode substrate 101 (step S70 in Fig. 3). This completes the electrochromic device 100.

[0056] 5B , when the first support plate 106 and the second support plate 107 are used, the first support plate 106 and the second support plate 107 are separated from the electrochromic device 100 after the bonding step (step S70). Furthermore, in this step of separating the first support plate 106 and the second support plate 107, separation (air bubbles) may occur between the electrolyte membrane 103 and the electrochromic layer 102 and / or the counter electrode layer 105. For this reason, the electrochromic device 100 may be heated and pressed to degas (remove air bubbles) as needed.

[0057] Furthermore, to ensure tight adhesion between the first electrode substrate 101 and the second electrode substrate 104, an adhesive 108 or the like may be used (see FIG. 6 ). This improves the mechanical strength of the electrochromic device 100. For example, the areas of the electrolyte film 103, the electrochromic layer 102, and the counter electrode layer 105 may be adjusted to be smaller than the areas of the first electrode substrate 101 and the second electrode substrate 104, and the adhesive 108 may be provided on the outer edge of the electrochromic device 100. Then, in the bonding step (step S70, see FIG. 3 ), the first electrode substrate 101 and the second electrode substrate 104 may be bonded together. The adhesive 108 may be provided, for example, on the first electrode and the second electrode (e.g., ITO film) formed on the first electrode substrate 101 and the second electrode substrate 104, respectively. The material of the adhesive 108 is not particularly limited, and a general-purpose adhesive such as a UV-curable epoxy resin or a UV-curable acrylic adhesive may be used.

[0058] The above-described manufacturing method for the electrochromic device 100 using the laminate 300 eliminates the need to form the electrolyte layer 103 by coating or other methods at the manufacturing site. This eliminates the need for processes at the manufacturing site, such as preparing the electrolyte layer paint (a fluid gel electrolyte or electrolyte solution), applying a sealant to prevent electrolyte leakage to the surrounding area, coating, and drying. This allows for simpler and more efficient formation of the electrolyte layer. In particular, when flexible resin substrates are used for the first electrode substrate 101 and the second electrode substrate 104, conventional manufacturing methods that include a coating step have a problem with leakage of the electrolyte layer paint. In contrast, the electrolyte film 103 included in the laminate 300 has already had at least half to a majority of the solvent (second solvent) removed, eliminating the risk of leakage. Thus, the laminate 300 is particularly suitable for manufacturing flexible electrochromic devices using flexible resin substrates.

[0059] Furthermore, compared to conventional electrolyte layer-forming paints, the laminate 300 is easier to store, control quality, transport, etc. Furthermore, the fabricated laminate 300 can be cut to a desired size in advance.

[0060] The use of the laminate 300 having the above advantages allows for easier and more efficient mass production of electrochromic devices, particularly flexible electrochromic devices. Furthermore, because the laminate 300 is flexible, it is also possible to manufacture (mass-produce) the electrochromic device 100 by roll-to-roll processing using the laminate 300.

[0061] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate 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 Laminate 300 In this example, a laminate 300 having the structure shown in FIG. 1 was prepared according to the following procedure (see FIGS. 3 and 4).

[0063] (1) Preparation of Coating Solution (Composition for Forming Electrolyte Film) In this example, polymethyl methacrylate (PMMA) was used as the polymer, and lithium perchlorate (LiClO ４ A coating solution was prepared using propylene carbonate (PC) as a plasticizer (first solvent) and acetonitrile (ACN) as a solvent (second solvent). The viscosity of a polymer solution prepared by dissolving 2.0 g of PMMA in 50 mL of tetrahydrofuran (THF) at 23°C was 28 mPa s.

[0064] First, 4 g of PMMA powder was placed in a 100 mL screw tube, and a mixture of 12 g of PC and 42 g of ACN was poured into the tube while stirring with a magnetic stirrer, to dissolve the PMMA powder in the mixture. ４ The resulting coating solution had a viscosity of 7,380 mPa·s at 23°C.

[0065] (2) Application of Coating Liquid and Solvent Removal 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. The coating liquid was applied to the surface 10a of the first support film 10, on which the silicone resin coating layer was provided, 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) from the coating film 30, and an electrolyte membrane 103 was formed.

[0066] (3) Lamination of Second Support Film 20 A PET film with a silicone resin coating layer (manufactured by Nippa Corporation, product number: JOL, thickness: 50 μm, peel load: 30 mN / 50 mm width) was used as the second support film 20. The second support film 20 was laminated on the electrolyte membrane 103 such that the surface 20 a of the second support film 20 provided with the silicone resin coating layer was in contact with the electrolyte membrane 103, thereby obtaining the laminate 300 of this example.

[0067] The average thickness of the electrolyte membrane 103 in the produced laminate 300 was 80 μm. The average thickness of the electrolyte membrane 103 was determined by measuring 10 random locations using a dial gauge and calculating the arithmetic mean value.

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

[0069] (1) Formation of Electrochromic Layer 102 A metallo-supramolecular 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 metallo-supramolecular polymer solution with a concentration of 8.4 mg / mL.

[0070]

[0071] A first electrode substrate (100 mm long x 100 mm wide x 150 μm thick) 101 was prepared, which consisted of a flexible PET substrate coated with ITO (first electrode). 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 ). The prepared metallo-supramolecular polymer solution was spray-coated onto the first electrode of the first electrode substrate 101 using a spray coater (API40RD, manufactured by Apiros) 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, and stage temperature: 60°C.

[0072] (2) Formation of Counter Electrode Layer 105: A Prussian blue nickel derivative, NiHCF (nickel hexacyanoferrate, Ni(II) ３ [Fe(III)CN ６ ] ２An aqueous dispersion (concentration: 0.3 mg / mL) of NiHCF was prepared. An electrode substrate having the same configuration as the first electrode substrate 101 described above was prepared as the second electrode substrate 104, and was supported on a second support plate (glass plate, thickness: 0.7 mm) 107 via an adhesive film (not shown) (see FIG. 5A ). The prepared NiHCF aqueous solution was spray-coated onto the second electrode of the second electrode substrate 104 using the spray coater used to form the electrochromic layer 102, to form the 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, stage temperature: 80°C.

[0073] (3) Bonding of the Electrolyte Membrane 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 103 b of the electrolyte membrane 103. The other surface 103 b was then bonded to the counter electrode layer 105 on the second electrode substrate 104 (see FIG. 5A ). The areas of the electrolyte membrane 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 the electrolyte membrane 103 and the counter electrode layer 105 were bonded together, the electrolyte membrane 103 and the counter electrode layer 105 were not present on the surface of the outer peripheral portion of the second electrode substrate 104, and there was a region where the ITO film (second electrode) on the surface of the second electrode substrate 104 was exposed. An ultraviolet-curing acrylic adhesive (XVL-90T3, manufactured by Kyoritsu Chemical Co., Ltd.) 108 was applied to this region by printing (the adhesive 108 is not shown in FIG. 5A, see FIG. 6).

[0074] (4) Bonding of Electrolyte Film 103 and 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 on the surface of the outer peripheral edge of the first electrode substrate 101 where the ITO film (first electrode) on the surface of the first electrode substrate 101 is exposed. When bonding the electrolyte film 103 and the electrochromic layer 102, the ultraviolet-curable acrylic adhesive 108 applied to the second electrode substrate 104 comes into contact with 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. The surface 103a was then 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 together via the adhesive 108. The adhesive 108 was then cured by irradiating the backsides of the first electrode substrate 101 and the second electrode substrate 104 with ultraviolet light (the adhesive 108 is not shown in FIG. 5B ; see FIG. 6 ). Next, the first support plate 106 and the second support plate 107 were separated from the first electrode substrate 101 and the second electrode substrate 104, respectively, to obtain the electrochromic device 100 of this example. In this example, the resulting electrochromic device 100 was further heat-pressed using a heating laminator to remove any internal air bubbles.

[0076] [Examples 1-2 to 1-4] In Examples 1-2 to 1-4, laminates 300 were produced in the same manner as in Example 1-1, except that the composition of the coating solution (the blending amount of each component) was changed as shown in Table 1. The viscosity of the coating solution and the average film thickness of the obtained electrolyte film in each example are shown in Table 1. In Examples 1-2 to 1-4, electrochromic devices 100 were further produced in the same manner as in Example 1-1 using the produced laminates 300.

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

[0078] [Evaluation] The following evaluations were carried out for Examples 1-1 to 1-4 and 2. The results are shown in Table 1.

[0079] 1. Film Formability In the production of the laminate 300 of Examples 1-1 to 1-4 and 2, the film formability of the electrolyte membrane 103 formed on the first support film 10 was evaluated according to the following evaluation criteria. If the overall evaluation result of the film formability below is A or B, it can be determined that the film formability is good. In the evaluation criteria below, "smoothness" was evaluated by visually observing the surface of the electrolyte membrane 103. "Adhesion" was evaluated by the ease with which the second support film 20 could be peeled from the electrolyte membrane 103. The easier the peeling, the less sticky the electrolyte membrane 103 felt, and the higher the evaluation of "adhesion" was determined to be. In the evaluation criteria below, if the evaluation result of "adhesion" is A or B, it can be determined that the fluidity of the electrolyte membrane 103 is kept low, the electrolyte membrane 103 has high self-supporting properties as a membrane, and is easy to handle.

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

[0081] (2) Evaluation criteria for smoothness G: No fine irregularities (citrus peel, orange peel), drying irregularities, or electrolyte precipitation (crystallization) are observed on the surface of the electrolyte membrane 103. NG: Any of fine irregularities (citrus peel, orange peel), drying irregularities, or electrolyte precipitation (crystallization) is observed on the surface of the electrolyte membrane 103.

[0082] (3) Evaluation criteria for adhesiveness A: When the second support film 20 is peeled off, there is little stickiness and the shape of the electrolyte membrane 103 can be maintained over 95% or more of the area. B: When the second support film 20 is peeled off, the shape of the electrolyte membrane 103 can be maintained over 95% or more of the area, but there is a somewhat large stickiness. C: When the second support film 20 is peeled off, peeling failure occurs over more than 5% of the area.

[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 was A or B, it could be determined that the transferability was good.

[0084] <Evaluation criteria for transferability> A: None of defects, wrinkles, or bubbles (bubbles between the electrolyte membrane 103 and the counter electrode layer 105) were found in the electrolyte membrane 103. That is, the area of ​​the region where any of defects, wrinkles, or bubbles existed (hereinafter referred to as the "area of ​​the defective region") was 0% of the area of ​​the electrolyte membrane 103. B: Any of defects, wrinkles, or bubbles was found in the electrolyte membrane 103, but the area of ​​the defective region was 10% or less of the area of ​​the electrolyte membrane 103. C: The area of ​​the defective region was more than 10% and less than 50% of the area of ​​the electrolyte membrane 103. D: The area of ​​the defective region was more than 50% of the area of ​​the electrolyte membrane 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 decoloring / coloring operations. As shown in FIG. 7 , the electrochromic device 100 was confirmed to exhibit a color change from purple (potential 0 V, reduced state Fe(II)) to colorless (potential 1.5 V, oxidized state Fe(III)), i.e., electrochromic characteristics (EC characteristics). The display state of the devices fabricated in each example was evaluated according to the following evaluation criteria. If the evaluation result was A or B, it can be determined that the device characteristics were good. Note that the presence of areas in the electrochromic device 100 where decoloring / coloring operations could not be confirmed is presumed to be due to the presence of areas (defective areas) in the electrolyte film 103 where any of missing parts, wrinkles, and air bubbles existed.

[0086] <Evaluation criteria for device characteristics> A: The area of ​​the region where the decoloring / coloring operation was confirmed was 95% or more of the area of ​​the electrochromic device 100. B: The area of ​​the region where the decoloring / coloring operation was confirmed was 80% or more but less than 95% of the area of ​​the electrochromic device 100. C: The area of ​​the region where the decoloring / coloring operation was confirmed was less than 80% of the area of ​​the electrochromic device 100. D: The transferability of the electrolyte film 103 was poor (transferability evaluation result: D), so assembly of the electrochromic device was impossible ().

[0087] The abbreviations used in the table have the following meanings: PMMA: polymethyl methacrylate LiClO ４ : Lithium perchlorate PC: Propylene carbonate ACN: Acetonitrile THF: Tetrahydrofuran

[0088] As shown in Table 1, in Examples 1-1 to 1-4, in which the viscosity of the polymer solution obtained by dissolving 2.0 g of polymer (PMMA) in 50 mL of THF was 28 mPa s at 23° C., the evaluation results for film-formability, transferability, and device characteristics were all good. Among these, in Examples 1-2 to 1-4, in which the viscosity of the coating liquid (electrolyte film-forming composition) was 250 to 300 mPa s, the evaluation results for film-formability were superior (film-formability evaluation result: A).

[0089] On the other hand, in Example 2, in which the viscosity at 23 °C of the polymer solution obtained by dissolving 2.0 g of polymer (PMMA) in 50 mL of THF was less than 10 mPa·s, both film-forming and transferability were poor. Furthermore, since a laminate 300 with sufficient transferability could not be produced, an electrochromic device 100 could not be produced in Example 2 (device characteristic evaluation result: D). One of the reasons for the poor film-forming ability in Example 2 is presumed to be that the viscosity of the coating solution (electrolyte film-forming composition) was low due to the small molecular weight of the polymer, which resulted in the coating drying faster. Another reason for the poor transferability in Example 2 is presumed to be that the adhesion of the electrolyte film 103 was low due to the small molecular weight of the polymer, which prevented sufficient adhesion to the counter electrode layer 105, resulting in poor peeling of the second support film 20.

[0090] The polymer viscosity in these examples was measured as follows. All of the polymer viscosity values ​​described in this specification and the appended claims are measured by this method. Viscosity measurement device: Brookfield digital viscometer (B-type viscometer) for low viscosity "LVDVE" (manufactured by AMETEK Brookfield, compliant with JIS Z8803). Viscosity measurement conditions: Probe: LV5, rotation speed: 60 rpm

[0091] By using the above laminate, an electrolyte layer (electrolyte film) of an electrochromic device can be formed more simply and efficiently. Furthermore, even when a flexible resin substrate is used as the electrode substrate in an electrochromic device, the risk of electrolyte leakage to the surroundings can be almost eliminated by manufacturing the electrochromic device using the laminate of the above embodiment. The electrochromic device manufactured in this manner can be used for a variety of applications, such as light-control glass devices and display devices.

[0092] REFERENCE SIGNS LIST 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. 1. A laminate for manufacturing an electrochromic device, comprising: Electrolyte film, a first support film laminated on one surface of the electrolyte membrane; and a second support film laminated on the other surface of the electrolyte membrane; The electrolyte membrane includes a polymer, an electrolyte, and a plasticizer as a first solvent, and has an average thickness of 10 μm to 500 μm; A laminate, wherein a polymer solution obtained by dissolving 2.0 g of the polymer in 50 mL of tetrahydrofuran at 23° C. has a viscosity of 10 mPa·s to 50 mPa·s.

2. 2. The laminate of claim 1, wherein the polymer comprises 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 of claim 2 , wherein the polymer comprises 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 includes 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 an ionic liquid.

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

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

8. A composition for forming the electrolyte membrane contained in the laminate according to any one of claims 1 to 7, The polymer, the electrolyte, a plasticizer as the first solvent, and a second solvent are included, A composition having a viscosity of 250 mPa·s to 7400 mPa·s at 23°C.

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

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

11. 1. A method for manufacturing an electrochromic device, comprising the steps of: Providing a laminate according to any one of claims 1 to 7; forming an electrochromic layer on a first electrode substrate, the electrochromic layer including a metallo-supramolecular polymer formed by alternating metal cations and organic ligands linked together by coordinate bonds; forming a counter electrode layer on a second electrode substrate; peeling off the second support film from the laminate to expose the other surface of the electrolyte membrane; bonding the exposed other surface of the electrolyte film to the counter electrode layer on a second electrode substrate; peeling off a first support film from the electrolyte film bonded to the counter electrode layer to expose the one surface of the electrolyte film; and A method for manufacturing an electrochromic device comprising: laminating the exposed surface of the electrolyte film to the electrochromic layer on a first electrode substrate.

12. The counter electrode layer is represented by the formula: M(II) 3 [Fe(III)CN ６ ] ２ The method for producing an electrochromic device according to claim 11, comprising a metal hexacyanoferrate represented by the formula: (wherein M is at least one selected from Fe, Ni, and Zn).