Prussian blue-type metal complex dispersion and method for producing thin film material containing Prussian blue-type metal complex

Abstract

To provide a prussian blue type metal complex fluid dispersion capable of obtaining a thin-film material containing prussian blue type metal complex having a low haze with a membrane surface difficult to crack and also to provide a production method of a thin-film material containing prussian blue type metal complex capable of producing the thin-film material.SOLUTION: A prussian blue type metal complex fluid dispersion includes a prussian blue type metal complex, polyvinyl alcohol and latex.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a Prussian blue-type metal complex dispersion liquid that can be used for producing electrochromic devices and the like, and a method for producing a thin film material containing a Prussian blue-type metal complex using the same. [Background technology]

[0002] Prussian blue is a metal complex compound that has long been known as a blue pigment, and has a structure in which iron elements are three-dimensionally assembled via cyano groups. Compounds in which part of the iron element in Prussian blue is replaced with other metal elements are also known, and these compounds, including Prussian blue, are called Prussian blue-type metal complexes. In recent years, the application of Prussian blue-type metal complexes as electrochromic materials for electrochromic devices has been investigated.

[0003] Known electrochromic element configurations include, for example, those disclosed in Japanese Patent Laid-Open Publication No. 2018-185424 (Patent Document 1), which have electrochromic layers containing different electrochromic materials on two opposing electrodes, and an electrolyte layer containing an electrolyte (responsible for donating electrons and ions to the electrochromic material) between the electrochromic layers. When a Prussian blue-type metal complex is used in the electrochromic layer, it is necessary to form a uniform thin film containing the Prussian blue-type metal complex. One method for forming a thin film is to coat the Prussian blue-type metal complex as a nanoparticle dispersion. This method has the advantage of being able to mass-produce thin film materials containing Prussian blue-type metal complexes at low cost compared to methods such as vacuum deposition and sputtering. Methods for producing a Prussian blue-type metal complex nanoparticle dispersion are described, for example, in Japanese Patent Laid-Open No. 2006-256954 (Patent Document 2) and Akihiko Gotoh et al., "Simple Synthesis of Three Primary Color Nanoparticle Inks Prussian Blue and Its Analogues," IOP Publishing, Nanotechnology, 2007, 18, 345609 (Non-Patent Document 1), which describe that Prussian blue-type metal complex nanoparticles with excellent dispersion stability in a dispersion medium can be produced by mixing an aqueous solution containing an anionic metal cyano complex with an aqueous solution containing a metal cation, and then mixing this with a solution in which a ligand is dissolved in a solvent as a dispersant.

[0004] Furthermore, when forming a thin film material by forming a Prussian blue-type metal complex nanoparticle dispersion into a film, it is known to use a dispersion containing an appropriate binder to maintain the dispersibility of the Prussian blue-type metal complex. For example, Japanese Patent Laid-Open Publication No. 219723 / 1989 (Patent Document 3) discloses a microparticle dispersion containing a microparticle metal complex, a medium, and a water-soluble polymer, and describes the use of anion-modified polyacrylamide or anion-modified polyvinyl alcohol as the water-soluble polymer to obtain a microparticle dispersion with good dispersion stability. However, when preparing a thin film material, cracks due to drying can occur, and even if there are no cracks immediately after preparation, cracks can develop over time. Increasing the amount of binder added is an effective way to prevent such cracks, but thin film materials containing Prussian blue-type metal complexes have the problem of increasing haze when the amount of binder added increases, and improvement is desired.

[0005] On the other hand, Japanese Patent Laid-Open Publication No. 2009-529146 (Patent Document 4) discloses a method for manufacturing an electrochromic device by wet coating a nano-dispersion composition containing Prussian blue, a dispersant, a binder, and an organic solvent, and describes that polyacrylic, polyethyleneimine, and polyurethane dispersants can be used as dispersants, and thermoplastic resins such as acrylic polymers, styrene polymers, and vinyl chloride polymers can be used as binders. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2018-185424 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-256954 [Patent Document 3] Japanese Patent Application Publication No. 1-219723 [Patent Document 4] Japanese Patent Application Laid-Open No. 2009-529146 [Non-patent literature]

[0007] [Non-Patent Document 1] Akihiko Gotoh et al., "Simple Synthesis of three primary color nanoparticle inks Prussian blue and its analogues", IOP Publishing, Nanotechnology, 2007, 18, 345609. Summary of the Invention [Problem to be solved by the invention]

[0008] The problem to be solved by the present invention is to provide a Prussian blue-type metal complex dispersion capable of producing a thin film material containing a Prussian blue-type metal complex that has low haze and is less likely to develop cracks on the film surface, and a method for producing a thin film material containing a Prussian blue-type metal complex that is capable of producing said thin film material. [Means for solving the problem]

[0009] The object of the present invention has been achieved by the following means. (1) A Prussian blue-type metal complex dispersion containing a Prussian blue-type metal complex, polyvinyl alcohol, and latex. (2) The Prussian blue-type metal complex dispersion liquid according to (1), wherein the glass transition temperature of the latex is 0° C. or lower. (3) A method for producing a thin film material containing a Prussian blue-type metal complex, which comprises applying the Prussian blue-type metal complex dispersion liquid according to (1) or (2) to the surface of a substrate and drying the applied liquid to form a thin film containing the Prussian blue-type metal complex. [Effects of the Invention]

[0010] The present invention provides a Prussian blue-type metal complex dispersion that can provide a thin film material containing a Prussian blue-type metal complex that has low haze and is less likely to develop cracks on the film surface, and a method for producing a thin film material containing a Prussian blue-type metal complex that can produce the thin film material. DETAILED DESCRIPTION OF THE INVENTION

[0011] The Prussian blue-type metal complex dispersion of the present invention contains a Prussian blue-type metal complex. The Prussian blue-type metal complex of the present invention is a compound having a structure in which metal atoms M are assembled three-dimensionally via iron atoms and cyano groups. Note that the three-dimensional structure may contain metal substitutions, defects, and the intrusion of ions or water into voids. Examples of Prussian blue-type metal complexes include Prussian blue (M=Fe) and compounds in which the metal atom M of Prussian blue is substituted with an atom other than iron (M=Ni, Co, Cu, Zn, etc.), and the metal atom M is not particularly limited.

[0012] The synthesis of Prussian blue-type metal complexes can be achieved by the synthesis of hexacyanoferrate ions [Fe(CN)6]. m- and a solution of a metal salt containing the metal element M, but the synthesis method is not particularly limited.

[0013] Hexacyanoferrate ion [Fe(CN)6] m- means that there are six cyanide ions, CN, for one iron atom or ion. -The charge m of the entire hexacyanoferrate ion, based on the valence of the iron center, is not particularly limited, but is typically 3 or 4. Specific examples of hexacyanoferrate ions include hexacyanoferrate(II) ion and hexacyanoferrate(III) ion. Metal salts containing hexacyanoferrate ions are compounds combining hexacyanoferrate ions with various cations, and may contain hydrated water within their structure. Specific examples include, but are not limited to, potassium hexacyanoferrate(II) trihydrate (yellow ferrite), sodium hexacyanoferrate(II) decahydrate, ammonium hexacyanoferrate(II) monohydrate, and potassium hexacyanoferrate(III) (red ferrite). Metal salts containing hexacyanoferrate ions may be used alone or in combination.

[0014] The metal salt containing the metal element M is not particularly limited, and is a compound combining the metal element M with various anions, etc., and may contain hydrate water, etc., in its structure. For example, when M=Fe, examples of the metal salt include, but are not limited to, iron(III) nitrate nonahydrate, iron(III) chloride hexahydrate, and iron(II) sulfate hexahydrate. The metal salt containing the metal element M may be used alone or in combination of two or more.

[0015] The solvents contained in the solution of the metal salt containing hexacyanoferrate ion and the solution of the metal salt containing metal element M are not particularly limited, and any known solvent capable of dissolving the respective metal salts can be used. Among these, water is preferred because of its excellent solubility for metal salts. However, known organic solvents, acids, bases, etc. may also be contained within limits that do not impair the solubility of the metal salt. Furthermore, the concentration of the metal salt in the solution is not particularly limited, but the metal salt concentration in each of the solutions of the metal salts is preferably 15% by mass or less, in order to ensure excellent dispersion stability of the resulting Prussian blue-type metal complex and to prevent the viscosity of the solution from becoming too high after mixing.

[0016] Since the synthesized Prussian blue-type metal complex contains impurities such as by-produced inorganic salts, it is preferable to purify it by washing with various known solvents. As a treatment method after washing, known methods such as centrifugation, decantation, and filtration can be used.

[0017] In the present invention, commercially available Prussian blue-type metal complexes can also be used. Examples of Prussian blue include iron(III) hexacyanoferrate(II) manufactured by Tokyo Chemical Industry Co., Ltd. and wFeHCF nanoparticle dispersion liquid manufactured by Kanto Chemical Co., Ltd.

[0018] The dispersion medium used in the Prussian blue-type metal complex dispersion of the present invention is not particularly limited. However, water is preferred, as it provides excellent solubility and dispersibility for the substances contained in the Prussian blue-type metal complex dispersion of the present invention. A water-miscible organic solvent may also be added to the extent that solubility and dispersibility are not impaired. Furthermore, it is preferable to add an appropriate dispersant to disperse the Prussian blue-type metal complex in the dispersion medium. It is preferable to prepare an ink containing a Prussian blue-type metal complex using a known dispersant such as those described in Patent Document 2 or Non-Patent Document 1, and then add polyvinyl alcohol and latex (described below) to the ink to obtain a Prussian blue-type metal complex dispersion. This allows for the production of a thin film material containing a Prussian blue-type metal complex with low haze. In particular, when water is used as the main dispersion medium, dispersants containing hexacyanoferrate ions that are easily soluble in water, such as potassium hexacyanoferrate(II) trihydrate (yellow ferrous iron), sodium hexacyanoferrate(II) decahydrate, ammonium hexacyanoferrate(II) monohydrate, and potassium hexacyanoferrate(III) (red ferrous iron), can be suitably used.

[0019] The Prussian blue-type metal complex dispersion of the present invention contains polyvinyl alcohol. Examples of polyvinyl alcohol in the present invention include common polyvinyl alcohols, as well as cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, silanol-modified polyvinyl alcohol, acetoacetyl-modified polyvinyl alcohol, and other polyvinyl alcohol derivatives. However, because acetic acid liberated over time from the acetate ester moieties derived from the vinyl acetate raw material may corrode electrode substrates such as indium tin oxide (ITO), it is preferable to use fully saponified polyvinyl alcohol with a saponification degree of 98% or higher or modified products thereof. For example, fully saponified polyvinyl alcohols manufactured by Kuraray Co., Ltd., such as 3-98 (degree of polymerization 300), 5-98 (degree of polymerization 500), 11-98 (degree of polymerization 1000), and 28-98 (degree of polymerization 1700), and modified polyvinyl alcohols such as 25-98R (degree of polymerization 1700) and RS-1713 (degree of polymerization 1300), are suitable. Among these, from the viewpoint of obtaining a Prussian blue-type metal complex-containing thin film material with low haze, it is particularly preferable to use polyvinyl alcohol with a degree of polymerization of less than 800. The polyvinyl alcohol may be used alone or in combination of two or more kinds.

[0020] The Prussian blue-type metal complex dispersion of the present invention contains latex. The term "latex" refers to a liquid in which a water-insoluble polymeric compound is dispersed in water. Examples of latex include aqueous dispersions of synthetic polymeric compounds such as vinyl acetate polymers, ethylene-vinyl acetate copolymers, (meth)acrylate polymers, styrene-(meth)acrylate copolymers, styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, isoprene polymers, chloroprene polymers, urethane polymers, and copolymers obtained by random polymerization, graft polymerization, or block polymerization of two or more of the monomers constituting these polymers, as well as natural rubber latex. These latexes may be used alone or in combination. While known latexes can be used in the present invention, when water is used as the dispersion medium, nonionic or anionic latexes are preferred to avoid impairing the dispersion state of the Prussian blue-type metal complex.

[0021] The average particle size of the latex in the present invention is not particularly limited, but is preferably 1 μm or less, and particularly preferably 0.5 μm or less, in order to keep the haze of the Prussian blue-type metal complex-containing thin film material low.

[0022] The latex in the present invention preferably has a glass transition temperature of 0° C. or lower, which makes it possible to obtain a thin film material containing a Prussian blue-type metal complex having higher crack prevention performance.

[0023] As the latex in the present invention, various commercially available products can be used. For example, various emulsions (vinyl acetate-based (50M, 51, HA-10A), acrylic-based (710A, 742A, 730L, 952B, 7320, 7400, DM772), vinyl acetate / acrylic-based (760H, 761HG, LDM7582, FK-420, FK-64S, FK-66IS, FK-66N, FK-68H), styrene / acrylic-based (966A)) manufactured by Japan Coating Resins Co., Ltd., various urethane emulsions (Hydran (registered trademark)) manufactured by DIC Corporation, etc. Examples of such urethane emulsions include the Superflex (registered trademark) series manufactured by Daiichi Kogyo Seiyaku Co., Ltd. (HW-171, HW-350, HW-311, HW-312B, WLS-201, WLS-202, WLS-210, WLS-213, AP-40(F), AP-40N, APX-101H, etc.), and various urethane emulsions manufactured by Daiichi Kogyo Seiyaku Co., Ltd. (Superflex (registered trademark) series, 126, 130, 150, 150HS, 170, 210, 300, 420, 420NS, 460, 460S, 470, 500M, 740, 820, 830HS, 860, 870, E-2000, E-4800, etc.).

[0024] The total content of polyvinyl alcohol and latex in the present invention is not particularly limited, but is preferably 10% by mass or more, and particularly preferably 40% by mass or more, based on the solid content of the Prussian blue-type metal complex, to prevent cracking in the Prussian blue-type metal complex-containing thin film material. On the other hand, if the total content is too high, electrochromic performance is likely to decrease, so a practical content is 100% by mass or less, based on the solid content of the Prussian blue-type metal complex. Furthermore, if the proportion of polyvinyl alcohol is too low, cracking of the Prussian blue-type metal complex-containing thin film material is likely to occur, and if the proportion is too high, haze is likely to increase. Therefore, the polyvinyl alcohol content is preferably 5 to 25% by mass, based on the solid content of the Prussian blue-type metal complex.

[0025] In addition to the Prussian blue-type metal complex, polyvinyl alcohol, and latex, the dispersion of the present invention may contain various compounds such as a surfactant, an ultraviolet absorber, a pH adjuster, etc. As the surfactant, known anionic, cationic, zwitterionic, and nonionic surfactants can be used, and among them, nonionic surfactants are preferred because they do not affect the electrochromic performance due to ions. Examples of nonionic surfactants include the NIKKOL BT series (BT-3, BT-5, BT-7, BT-9, BT-12, etc., polyoxyethylene alkyl ether surfactants) manufactured by Nikko Chemicals Co., Ltd., the DMH series (DMH-40, etc., polyoxyethylene alkyl ether surfactants) manufactured by Nippon Nyukazai Co., Ltd., and the Olfine (registered trademark) series (D-10A, D-10PG, E1004, E1010, E1020, E1030W, PD-001, PD-002W, PD-004, PD-005, EXP.4001, EXP.4200, EXP.4123, EXP.4300, WE-001, WE-002, WE-003, etc., acetylene surfactants) manufactured by Nissin Chemical Industry Co., Ltd.

[0026] The dispersion of the present invention can be produced using known dispersion treatment methods. For example, after dissolving a dispersant in a desired dispersion medium, the Prussian blue-type metal complex, polyvinyl alcohol, latex, and surfactant are added, followed by known dispersion treatment using a stirrer, propeller stirring, turbine stirring, homomixer stirring, media mill, pressure disperser, ultrasonic disperser, micromixer, static mixer, or the like. In particular, the method of mixing and dispersing a dispersant and a dispersion medium, as described in Patent Document 2 and Non-Patent Document 1, to prepare a dispersion containing nanoparticles of a Prussian blue-type metal complex is preferred for producing thin film materials with uniform thicknesses using known coating and printing methods. The solids concentration in the dispersion is not particularly limited, but a high solids concentration increases the viscosity of the coating liquid, making it difficult to form a uniform layer. Therefore, a solids concentration of 20% by mass or less is preferred, more preferably 15% by mass or less. The lower limit is preferably 0.1% by mass or more.

[0027] The substrate on which the dispersion of the present invention is formed into a film is not particularly limited, but in order to use the Prussian blue-type metal complex-containing thin film material as an electrochromic material, it is preferable that the substrate has optical transparency and electrical conductivity. Examples of substrates include glass and films on which a conductive metal oxide film such as tin oxide, indium tin oxide (ITO), antimony-doped tin oxide (ATO), zinc oxide, indium zinc oxide (IZO), or antimony-doped zinc oxide (AZO) is laminated.

[0028] The method for forming a film from the dispersion of the present invention is not particularly limited, and examples thereof include known coating methods such as bar coating, spin coating, slit coating, die coating, blade coating, gravure coating, curtain coating, spray coating, and kiss coating, and known printing methods such as gravure printing, flexographic printing, inkjet printing, screen printing, offset printing, gravure offset printing, dispenser printing, and pad printing. Furthermore, the dispersion coated or printed by these methods can be dried by known methods such as hot air drying, infrared drying, and natural drying to obtain a Prussian blue-type metal complex-containing thin film material. [Example]

[0029] The present invention will be described in detail below using examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention. In addition, percentages in the description are by mass unless otherwise specified.

[0030] <Synthesis of Prussian Blue> 215 g (533 mmol) of iron(III) nitrate nonahydrate was dissolved in 2000 g of distilled water to obtain an aqueous solution of iron(III) nitrate. Next, 194 g (400 mmol) of sodium hexacyanoferrate(II) decahydrate was dissolved in 2000 g of distilled water to obtain an aqueous solution of sodium hexacyanoferrate(II). Subsequently, while the aqueous solution of iron(III) nitrate was being stirred with a propeller at a rotation speed of 50 rpm, the aqueous solution of sodium hexacyanoferrate(II) was added dropwise to the aqueous solution of iron(III) nitrate using an EYELA MP-2000A microtube pump. After the entire amount of the aqueous solution of sodium hexacyanoferrate(II) was added dropwise, the mixture was stirred with the propeller at a rotation speed of 50 rpm for 5 minutes. The resulting slurry containing Prussian blue was diluted to approximately 20 L with distilled water and allowed to stand. After Prussian blue precipitated, the supernatant was removed. Similarly, the slurry was diluted to approximately 20 L, allowed to settle naturally, and the supernatant was removed. This procedure was repeated four more times. After removing the supernatant, the remaining slurry was centrifuged and the supernatant was removed, yielding 1,680 g of Prussian blue, a dark blue solid containing water.

[0031] <Preparation of Prussian blue ink> 58 g (119 mmol) of sodium hexacyanoferrate(II) decahydrate was dissolved in 200 g of distilled water, and the entire amount of Prussian blue (including water) was added to the solution. The mixture was stirred with a propeller at 300 rpm for 15 minutes at room temperature to obtain a Prussian blue ink. A small amount of this ink was dried at 120°C, and the solids concentration was determined to be 8.5% by mass based on the weight change before and after drying.

[0032] "Preparation of thin film material 1 containing Prussian blue-type metal complexes" Toyobo Co., Ltd.'s transparent conductive film CosmoCrysta 300R (PET film with ITO film) (surface resistance 250 Ω / □, thickness 125 μm, total light transmittance 86%, haze 1.0%), Prussian blue dispersion 1 having the following composition was applied to the ITO film surface with a bar coater at a wet coating rate of 15 g / m 2 The coating was dried at 25 to 30° C., thereby obtaining a thin film material 1 containing a Prussian blue-type metal complex.

[0033] <Prussian blue-type metal complex dispersion liquid 1> 15g of Prussian blue ink prepared as above 3-98 (Kuraray Co., Ltd., fully saponified polyvinyl alcohol, degree of polymerization 300) 0.13g 742A (Japan Coating Resin Co., Ltd. acrylic nonionic latex, Tg 45°C, solids concentration 50%, average particle size 0.01 μm) 1.3 g NIKKOL BT-7 (surfactant manufactured by Nikko Chemicals Co., Ltd.) 30mg 1.4g distilled water

[0034] "Preparation of thin film materials containing Prussian blue-type metal complexes 2" A Prussian blue-type metal complex-containing thin film material 2 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 2 described below.

[0035] <Prussian blue-type metal complex dispersion liquid 2> 15g of Prussian blue ink prepared as above 3-98 0.13g 730L (Japan Coating Resin Co., Ltd. acrylic nonionic latex, Tg -13°C, solids concentration 46%, average particle size 0.03μm) 1.4g NIKKOL BT-7 30mg 1.4g distilled water

[0036] "Preparation of thin film material 3 containing Prussian blue-type metal complexes" A Prussian blue-type metal complex-containing thin film material 3 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 3 described below.

[0037] <Prussian blue-type metal complex dispersion 3> 15g of Prussian blue ink prepared as above 3-98 0.13g Superflex 170 (Dai-ichi Kogyo Seiyaku Co., Ltd. urethane-based anionic latex, Tg 75°C, solid content 33%, average particle size 0.01 μm) 1.9 g NIKKOL BT-7 30mg 1.4g distilled water

[0038] "Preparation of thin film materials containing Prussian blue-type metal complexes 4" A Prussian blue-type metal complex-containing thin film material 4 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 4 described below.

[0039] <Prussian blue-type metal complex dispersion liquid 4> 15g of Prussian blue ink prepared as above 3-98 0.13g Superflex 420 (Dai-ichi Kogyo Seiyaku Co., Ltd. urethane-based anionic latex, Tg -10°C, solids concentration 32%, average particle size 0.01 μm) 2.0 g NIKKOL BT-7 30mg 1.4g distilled water

[0040] "Preparation of thin film material 5 containing Prussian blue-type metal complex" A Prussian blue-type metal complex-containing thin film material 5 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 5 described below.

[0041] <Prussian blue-type metal complex dispersion liquid 5> 15g of Prussian blue ink prepared as above 3-98 0.13g 1.8g of Hydran WLS-201 (DIC Corporation urethane-based anionic latex, Tg -50°C, solids concentration 35%, average particle size 0.05μm) NIKKOL BT-7 30mg 1.4g distilled water

[0042] "Preparation of thin film materials containing Prussian blue-type metal complexes 6" A Prussian blue-type metal complex-containing thin film material 6 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 6 described below.

[0043] <Prussian blue-type metal complex dispersion liquid 6> 15g of Prussian blue ink prepared as above 3-98 0.13g 1.8g of Hydran WLS-202 (DIC Corporation urethane-based anionic latex, Tg -50°C, solids concentration 35%, average particle size 0.05μm) NIKKOL BT-7 30mg 1.4g distilled water

[0044] "Preparation of thin film materials containing Prussian blue-type metal complexes 7" A Prussian blue-type metal complex-containing thin film material 7 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 7 described below.

[0045] <Prussian blue-type metal complex dispersion liquid 7> 15g of Prussian blue ink prepared as above 3-98 0.13g 1.8g of Hydran WLS-210 (DIC Corporation urethane-based anionic latex, Tg -15°C, solids concentration 35%, average particle size 0.05μm) NIKKOL BT-7 30mg 1.4g distilled water

[0046] "Preparation of thin film materials containing Prussian blue-type metal complexes 8" A Prussian blue-type metal complex-containing thin film material 8 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 8 described below.

[0047] <Prussian blue-type metal complex dispersion liquid 8> 15g of Prussian blue ink prepared as above 3-98 0.13g 1.8g of Hydran WLS-213 (DIC Corporation urethane-based anionic latex, Tg -15°C, solids concentration 35%, average particle size 0.05μm) NIKKOL BT-7 30mg 1.4g distilled water

[0048] "Preparation of thin film material 9 containing Prussian blue-type metal complex" A Prussian blue-type metal complex-containing thin film material 9 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 9 described below.

[0049] <Prussian blue-type metal complex dispersion liquid 9> 15g of Prussian blue ink prepared as above 5-98 (Kuraray Co., Ltd., fully saponified polyvinyl alcohol, degree of polymerization 500) 0.13g Hydran WLS-213 1.8g NIKKOL BT-7 30mg 1.4g distilled water

[0050] "Preparation of thin film materials containing Prussian blue-type metal complexes 10" A Prussian blue-type metal complex-containing thin film material 10 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 10 described below.

[0051] <Prussian blue-type metal complex dispersion liquid 10> 15g of Prussian blue ink prepared as above 25-98R (Kuraray Co., Ltd., silanol-modified polyvinyl alcohol, polymerization degree 1700) 0.13 g Hydran WLS-213 1.8g NIKKOL BT-7 30mg 1.4g distilled water

[0052] "Preparation of thin film materials containing Prussian blue-type metal complexes 11" A Prussian blue-type metal complex-containing thin film material 11 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 11 described below.

[0053] <Prussian blue-type metal complex dispersion liquid 11> 15g of Prussian blue ink prepared as above 3-98 0.38g Hydran WLS-213 1.8g NIKKOL BT-7 30mg 3.7g distilled water

[0054] "Preparation of thin film material 12 containing Prussian blue-type metal complexes" A Prussian blue-type metal complex-containing thin film material 12 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 12 described below.

[0055] <Prussian blue dispersion 12> 15g of Prussian blue ink prepared as above 3-98 0.26g Hydran WLS-213 1.8g NIKKOL BT-7 30mg 2.6g distilled water

[0056] "Preparation of thin film material 13 containing Prussian blue-type metal complexes" A Prussian blue-type metal complex-containing thin film material 13 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 13 described below.

[0057] <Prussian blue dispersion 13> 15g of Prussian blue ink prepared as above 3-98 64mg Hydran WLS-213 1.8g NIKKOL BT-7 30mg 0.84g distilled water

[0058] "Preparation of thin film material 14 containing Prussian blue-type metal complexes" A Prussian blue-type metal complex-containing thin film material 14 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 14 described below.

[0059] <Prussian blue-type metal complex dispersion liquid 14> 15g of Prussian blue ink prepared as above 3-98 38mg Hydran WLS-213 1.8g NIKKOL BT-7 30mg 0.61g distilled water

[0060] "Preparation of thin film materials containing Prussian blue-type metal complexes 15" A Prussian blue-type metal complex-containing thin film material 15 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 15 described below.

[0061] <Prussian blue-type metal complex dispersion liquid 15> 15g of Prussian blue ink prepared as above 3-98 0.13g Hydran WLS-213 2.6g NIKKOL BT-7 30mg 1.4g distilled water

[0062] "Preparation of thin film materials containing Prussian blue-type metal complexes 16" A Prussian blue-type metal complex-containing thin film material 16 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 16 described below.

[0063] <Prussian Blue Dispersion 16> 15g of Prussian blue ink prepared as above 3-98 0.13g Hydran WLS-213 1.1g NIKKOL BT-7 30mg 1.4g distilled water

[0064] "Preparation of thin film materials containing Prussian blue-type metal complexes 17" A Prussian blue-type metal complex-containing thin film material 17 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 17 described below.

[0065] <Prussian blue dispersion 17> 15g of Prussian blue ink prepared as above 3-98 0.13g Hydran WLS-213 0.73g NIKKOL BT-7 30mg 1.4g distilled water

[0066] "Preparation of thin film materials containing Prussian blue-type metal complexes 18" A Prussian blue-type metal complex-containing thin film material 18 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 18 described below.

[0067] <Prussian Blue Dispersion 18> 15g of Prussian blue ink prepared as above 3-98 0.13g Hydran WLS-213 0.18g NIKKOL BT-7 30mg 1.4g distilled water

[0068] "Preparation of thin film material 19 containing Prussian blue-type metal complexes" A Prussian blue-type metal complex-containing thin film material 19 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 19 described below.

[0069] <Prussian blue-type metal complex dispersion liquid 19> 15g of Prussian blue ink prepared as above 3-98 0.13g Hydran WLS-213 0.11g NIKKOL BT-7 30mg 1.4g distilled water

[0070] "Preparation of thin film material 20 containing Prussian blue-type metal complexes" A Prussian blue-type metal complex-containing thin film material 20 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 20 described below.

[0071] <Prussian blue-type metal complex dispersion liquid 20> 15g of Prussian blue ink prepared as above 3-98 0.13g NIKKOL BT-7 30mg 1.4g distilled water

[0072] "Preparation of thin film material 21 containing Prussian blue-type metal complexes" A Prussian blue-type metal complex-containing thin film material 21 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 21 described below.

[0073] <Prussian blue-type metal complex dispersion liquid 21> 15g of Prussian blue ink prepared as above 3-98 0.77g NIKKOL BT-7 30mg 7.2g distilled water

[0074] "Preparation of thin film material 22 containing Prussian blue-type metal complexes" A Prussian blue-type metal complex-containing thin film material 22 was prepared in the same manner as in the preparation of the Prussian blue-type metal complex-containing thin film material 1, except that the Prussian blue-type metal complex dispersion liquid 1 was changed to the Prussian blue-type metal complex dispersion liquid 22 described below.

[0075] <Prussian Blue Dispersion 22> 15g of Prussian blue ink prepared as above Hydran WLS-213 2.2g NIKKOL BT-7 30mg 0.27g distilled water

[0076] <Haze measurement> The haze of the Prussian blue-type metal complex-containing thin film materials 1 to 22 obtained as described above was measured using a haze meter HZ-V3 manufactured by Suga Test Instruments Co., Ltd. The average value of measurements taken at three locations is shown in Table 1.

[0077] <Crack evaluation> The film surfaces of Prussian blue-type metal complex-containing thin film materials 1-22 were observed immediately after preparation using a Keyence VHX-5000 digital microscope (magnification: 500x). No cracks were observed on the surface of any of the Prussian blue-type metal complex-containing thin film materials. Next, Prussian blue-type metal complex-containing thin film materials 1-22 were heated in a dryer at 120°C for 1 day (24 hours), and then the film surfaces of the Prussian blue-type metal complex-containing thin films were observed using a Keyence VHX-5000 digital microscope (magnification: 500x). This procedure was repeated, and the total number of heating days until cracks appeared was recorded as the durability period. The results are shown in Table 1.

[0078] [Table 1]

[0079] Table 1 shows the effects of the present invention.

Claims

1. The ink contains a Prussian blue-type metal complex, polyvinyl alcohol, and latex, the total content of the polyvinyl alcohol and the latex is 10 to 100% by mass based on the solid content of the Prussian blue-type metal complex; A Prussian blue-type metal complex dispersion liquid, characterized in that the content of the polyvinyl alcohol is 5 to 25 mass % relative to the solid content of the Prussian blue-type metal complex.

2. 2. The Prussian blue-type metal complex dispersion according to claim 1, wherein the glass transition temperature of the latex is 0° C. or lower.

3. 3. A method for producing a thin film material containing a Prussian blue-type metal complex, comprising applying the Prussian blue-type metal complex dispersion liquid according to claim 1 or 2 to a substrate surface and drying the coating to form a thin film containing a Prussian blue-type metal complex.

Images