Composite particles, their manufacturing method, and electrochromic devices using the same

Abstract

To provide composite particles using a metallosupramolecular polymer for improving memory characteristics of an electrochromic device, a method for producing the same, and an electrochromic device using the same.SOLUTION: Composite particles contain particles of a laminar inorganic-organic covalent bond substance composed of a laminar silicate compound having an organic group and metal particles between layers, and a metallosupramolecular polymer coating the particles, wherein the organic group is represented by X1-L1, X1 is a functional group selected from a group consisting of a heterocyclic group, an amine group, an amide group, a thioether group, a sulfone group, a nitro group, a carboxyl group, a linear or branched alkyl group, a linear or branched alkylamine group, a linear or branched quaternary alkylammonium group, a quaternary aryl ammonium group, coumarin and a derivative thereof, L1 is a divalent group, and the metallosupramolecular polymer contains an organic ligand and metal ions coordinate to the organic ligand.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to composite particles, a method for producing the same, and an electrochromic device using the same, and more particularly to composite particles containing a metallo-supramolecular polymer, a method for producing the same, and an electrochromic device using the same. [Background technology]

[0002] In recent years, layered inorganic-organic composites, in which organic substances exist between layers of layered inorganic compounds, have been actively studied because they may have the properties of both inorganic and organic substances. For example, the synthesis of layered inorganic-organic composites in which a silicic acid compound and an organic group possessed by the imidazoline group are covalently bonded using an imidazoline derivative has been reported (see, for example, Non-Patent Documents 1 to 4).

[0003] Non-Patent Documents 1 to 4 disclose that the above-mentioned layered inorganic-organic composite can be obtained by adding triethoxy-3-(2-imidazolin-1-yl)propylsilane dropwise to and mixing an aqueous solution of metal acetates of nickel or magnesium or a dispersion of nickel oxide, and then heating the mixture at 80 to 170°C for 10 hours to 6 days. Such composites are expected to be used as adsorbents and luminescent materials.

[0004] Meanwhile, electrochromic materials have been attracting attention as display materials and light-modulating materials. A variety of electrochromic devices with excellent response have been developed using organic / metal hybrid polymers as electrochromic materials, which combine the advantages of conventional organic and inorganic electrochromic materials (see, for example, Patent Documents 1 and 2). Patent Documents 1 and 2 disclose organic / metal hybrid polymers in which the organic ligand is a terpyridine group or a phenanthroline group to which a metal ion is coordinated, and electrochromic devices using the same.

[0005] Furthermore, a composite has been developed in which an organic / metal hybrid polymer is intercalated into a layered silicate (see, for example, Patent Document 3). Patent Document 3 reports that adding an organic / metal hybrid polymer to an aqueous solution in which a smectite-based layered silicate is dispersed results in a composite in which the organic / metal hybrid polymer is intercalated between the layers of the layered silicate. According to Patent Document 3, by forming such a composite, the redox potential of the organic / metal hybrid polymer is reduced, thereby reducing the operating voltage of the electrochromic device and improving its memory characteristics. However, further improvements in memory characteristics are required for practical application, and power savings are expected. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-112957 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-188517 [Patent Document 3] Japanese Patent Application Publication No. 2018-90912 [Non-patent literature]

[0007] [Non-Patent Document 1] Kazuko Fujii et al., 59th Clay Science Symposium, "Synthesis and Evaluation of Layered Inorganic-Imidazoline Composites" [Non-patent document 2] K. Fujii et al., Journal of Inorganic and Organometallic Polymers and Materials (2019) 29:745-757 [Non-patent document 3] Kazuko Fujii et al., 63rd Clay Science Symposium, "Synthetic Conditions and Structure of Layered Inorganic-Imidazoline Covalent Bonds" [Non-patent document 4] Kazuko Fujii et al., 100th Annual Meeting of the Spring Meeting, Proceedings "Morphological Observation of Layered Inorganic-Imidazoline Covalent Bonds" Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a composite particle using a metallo-supramolecular polymer that improves the memory characteristics of an electrochromic device, a method for producing the same, and an electrochromic device using the same. [Means for solving the problem]

[0009] The composite particles according to the present invention contain particles of a layered inorganic-organic covalent bond in which a silicate compound and an organic group are covalently bonded, and a metallo-supramolecular polymer coating the particles, wherein the organic group is represented by X1-L1, where X1 is a functional group selected from the group consisting of a heterocyclic group, an amine group, an amide group, a thioether group, a sulfone group, a nitro group, a carboxyl group, a linear or branched alkyl group, a linear or branched alkylamine group (including primary, secondary, and tertiary groups), a linear or branched quaternary alkylammonium group, a quaternary arylammonium group, coumarin, and derivatives thereof, and L1 is a divalent group, and the metallo-supramolecular polymer contains an organic ligand and a metal ion coordinated to the organic ligand, thereby solving the above-mentioned problem. The mass ratio of the metallo-supramolecular polymer to the particles may be in the range of 0.1 to 40. The mass ratio of the metallo-supramolecular polymer to the particles may be in the range of 0.6 to 30. The X1 may be an imidazoline group. The layered inorganic-organic covalent bond may be represented by chemical formula (1): (M 1 x1 n+ ,mH2O)(M 2 x2 M 3 x3 )R z (Si k M 4 x4 )Op (OH) q (1) where M 1 is at least one element selected from the group consisting of alkali metal elements, Group 2 elements, and transition metal elements, and M 2 is the M 1 is an element selected from the group consisting of alkali metal elements, Group 2 elements, and transition metal elements, which is different from or identical to M 3 is the M 1 and the above M 2 Group 2 elements, Group 3 elements and transition metal elements, which are different from or identical to M 4 is the M 1 , said M 2 and the above M 3 is at least one element selected from the group consisting of alkali metal elements, Group 2 elements, Group 3 elements, and transition metal elements, which is different from or the same as M 1 where m, x1, x2, x3, x4, z, k, p, and q satisfy 0≦m≦100, 0≦x1≦4, 0≦x2≦2, 2≦x3≦4, 0≦x4≦3, 2.2≦z≦4.5, 2≦k≦5, 9≦p≦11, and 1.5≦q≦8, respectively. The layered inorganic-organic covalent composite may contain metal particles between the layers. The layered inorganic-organic covalent bond may be represented by chemical formula (2). (M y NP )(M 1 x1 n+ ,mH2O)(M 2 x2 M 3 x3 )R z (Si k M 4 x4 )O p (OH) q (2) where M NP are metal particles located between layers, and M 1is at least one element selected from the group consisting of alkali metal elements, Group 2 elements, and transition metal elements, and M 2 is the M 1 is an element selected from the group consisting of alkali metal elements, Group 2 elements, and transition metal elements, which is different from or identical to M 3 is the M 1 and the above M 2 Group 2 elements, Group 3 elements and transition metal elements, which are different from or identical to M 4 is the M 1 , said M 2 and the above M 3 is at least one element selected from the group consisting of alkali metal elements, Group 2 elements, Group 3 elements, and transition metal elements, which is different from or identical to M NP is the M 1 , said M 2 , said M 3 and the above M 4 wherein R is the organic group, and n is the M 1 and m, x1, x2, x3, x4, z, k, p, and q satisfy 0≦m≦100, 0≦x1≦3, 0≦x2≦2, 2≦x3≦3, 0≦x4≦2, 1≦y≦10, 2.2≦z≦4.5, 2≦k≦5, 9≦p≦11, and 1.5≦q≦8, respectively. The particle size of the composite particles may be in the range of 0.5 nm to 35 μm. The surface of the composite particle may be smooth. The organic ligand may be at least one selected from the group consisting of a terpyridine group, a phenanthroline group, a bipyridine group, an imino group, and derivatives thereof. The metal ion may be at least one selected from the group consisting of Pt, Cu, Ni, Pd, Ag, Mo, Fe, Co, Ru, Rh, Eu, Zn, Os, Cr, and Mn. The metallo-supramolecular polymer may be at least one type represented by a general formula selected from the group consisting of general formulas (I), (II) and (III). [ka] In the formula (I), M represents a metal ion, X represents a counter anion, S represents a spacer containing a carbon atom and a hydrogen atom or a spacer directly connecting two terpyridine groups, and R 1 ~R 4 each independently represents a hydrogen atom or a substituent, and n is an integer of 2 or more that represents the degree of polymerization, In the formula (II), M 1 ~M N (N is an integer of 2 or more) each independently represents a metal ion having a different redox potential, and X 1 ~X n (n is an integer of 2 or more) each independently represents a counter anion, and S 1 ~S N (N is an integer of 2 or more) each independently represent a spacer containing a carbon atom and a hydrogen atom or a spacer directly connecting two terpyridine groups, and R 1 1~R 1 N , R 2 1~R 2 N , R 3 1~R 3 N , R 4 1~R 4 N (N is an integer of 2 or more) each independently represents a hydrogen atom or a substituent, and n 1 ~n N are each independently an integer of 2 or more indicating the degree of polymerization, In the formula (III), M represents a metal ion, X represents a counter anion, A represents a spacer containing a carbon atom and a hydrogen atom or a spacer directly connecting two phenanthroline groups, and R 1 ~R 4 each independently represents a hydrogen atom or a substituent, and n is an integer of 2 or more that represents the degree of polymerization. The method for producing the above-mentioned composite particles according to the present invention comprises the steps of: preparing a particle dispersion in which particles of a layered inorganic-organic covalent bonded body in which a silicic acid compound and an organic group are covalently bonded are dispersed in at least one dispersion medium selected from the group consisting of methanol, ethanol, and water; preparing a polymer solution containing a metallo-supramolecular polymer; mixing and stirring the particle dispersion and the polymer solution; and removing the solvent, wherein the organic group is represented by X1-L1, where X1 is a functional group selected from the group consisting of a heterocyclic group, an amine group, an amide group, a thioether group, a sulfone group, a nitro group, a carboxyl group, a linear or branched alkyl group, a linear or branched alkylamine group (including primary, secondary, and tertiary), a linear or branched quaternary alkylammonium group, a quaternary arylammonium group, coumarin, and derivatives thereof; and L1 is a divalent group, and the metallo-supramolecular polymer contains an organic ligand and a metal ion coordinated to the organic ligand, thereby solving the above-mentioned problem. The mixing and stirring may involve mixing the particle dispersion and the polymer solution so that the mass ratio of the metallo-supramolecular polymer to the particles is in the range of 0.1 or more and 40 or less. The concentration of the particles in the particle dispersion may be in the range of 0.05 mg / mL to 10 mg / mL. The concentration of the metallo-supramolecular polymer in the polymer solution may be in the range of 2 mg / mL to 4 mg / mL. The method may further include coating the mixture obtained by mixing and stirring prior to removing the solvent. The electrochromic device according to the present invention comprises a first electrode, an electrochromic layer located on the first electrode and containing the above-mentioned composite particles, an electrolyte layer located on the electrochromic layer, and a second electrode located on the electrolyte layer, thereby solving the above-mentioned problem. [Effects of the Invention]

[0010] The composite particles of the present invention contain particles of a layered inorganic-organic covalent bond in which the above-mentioned silicic acid compound and an organic group are covalently bonded, and a metallo-supramolecular polymer coating the particles. Because the organic group is covalently bonded to the silicic acid compound, the organic group does not deintercalate. The metallo-supramolecular polymer coats the particles without intercalating between the layers. As a result, the layered silicic acid compound is negatively charged, which stabilizes the redox potential of the metal ions in the metallo-supramolecular polymer. Using this in an electrochromic layer can provide an electrochromic device with improved memory characteristics.

[0011] The method for producing composite particles of the present invention includes preparing a particle dispersion in which particles of the layered inorganic-organic covalent bonded material, in which the above-described silicic acid compound and organic group are covalently bonded, are dispersed in at least one dispersion medium selected from the group consisting of methanol, ethanol, and water; preparing a polymer solution containing a metallo-supramolecular polymer; mixing and stirring the particle dispersion and polymer solution; and removing the solvent. By using the specific dispersion medium described above, the layered inorganic-organic covalent bonded material is less likely to peel or swell, allowing the metallo-supramolecular polymer to coat the particles without intercalating between the layers. Furthermore, since the above-described composite particles can be produced simply by mixing and stirring and removing unnecessary solvent, no special equipment or techniques are required, making the method highly versatile. [Brief explanation of the drawings]

[0012] [Figure 1] Schematic diagram showing a cross section of a composite particle of the present invention. [Figure 2] Schematic diagram showing a silicon compound used in the composite particles of the present invention. [Figure 3] Schematic showing another layered inorganic-organic covalent bond. [Figure 4] Flowchart showing the steps for producing composite particles of the present invention [Figure 5] Schematic diagram showing an electrochromic device of the present invention. [Figure 6] SEM image of layered inorganic-organic covalently bonded particles [Figure 7] SEM image of the sample in Example 1 [Figure 8] SEM image of the sample in Example 2 [Figure 9] 1 shows an SEM image of the sample of Example 3. [Figure 10] 1 shows cyclic voltammograms of samples from Examples 1 to 3 and 5. [Figure 11] FIG. 11 shows the oxidation-reduction potentials of the samples of Examples 1 to 3 and 5 calculated from FIG. [Figure 12] Graph showing the change in transmittance (A) and color development (B) of the electrochromic device of Example 3. [Figure 13] Graph showing the change in transmittance (A) and color development (B) of the electrochromic device of Example 5. [Figure 14] FIG. 1 shows the memory characteristics of the electrochromic device of Example 3. [Figure 15] FIG. 1 shows the memory characteristics of the electrochromic device of Example 5. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that like elements are designated by like numbers and their description will be omitted.

[0014] (Embodiment 1) In the first embodiment, the composite particles of the present invention and the method for producing the same will be described. FIG. 1 is a schematic diagram showing a cross section of a composite particle of the present invention. FIG. 2 is a schematic diagram showing the silicon compound used in the composite particles of the present invention.

[0015] The composite particle 100 of the present invention contains a particle 102 (hereinafter simply referred to as a particle) made of a layered inorganic-organic covalent bonded material 101, and a metallo-supramolecular polymer 103 that coats the particle 102. Here, the layered inorganic-organic covalent bonded material 101 contains a silicon compound layer 110 and an organic group 120 covalently bonded thereto. The silicon compound layer 110 is preferably a layer of an inorganic compound containing silicon (Si), hydrogen (H), and oxygen (O).

[0016] The organic group 120 is represented by X1-L1, where X1 is a functional group selected from the group consisting of a heterocyclic group, an amine group, an amide group, a thioether group, a sulfone group, a nitro group, a carboxyl group, a linear or branched alkyl group, a linear or branched alkylamine group (including primary, secondary, and tertiary groups), a linear or branched quaternary alkylammonium group, a quaternary arylammonium group, coumarin, and derivatives thereof, and L1 is a divalent group. L1 of the organic group 120 is covalently bonded to the layer 110. When X1 includes an alkyl chain, it typically has 1 to 30 carbon atoms.

[0017] The metallo-supramolecular polymer 103 contains an organic ligand and a metal ion coordinated to the organic ligand. Such a metallo-supramolecular polymer 103 exhibits electrochromic properties. In the layered inorganic-organic covalent bonded structure 101, the organic group 120 is covalently bonded to the silicon compound layer 110, so the metallo-supramolecular polymer 103 coats the particles 102 without intercalating between the layers 110. This configuration makes the layered inorganic-organic covalent bonded structure 101 negatively charged, stabilizing the metal ions in the metallo-supramolecular polymer 103. As a result, the redox potential of the metallo-supramolecular polymer 103 is stabilized, and its use in an electrochromic layer can provide an electrochromic device with improved memory properties.

[0018] Each component will be described in detail below. The heterocyclic group of the organic group 120 is preferably a nitrogen-containing heterocyclic group. More preferably, the nitrogen-containing heterocyclic group is a pyrrole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, an imidazole group, an imidazoline group, an imidazolidine group, a pyrazole group, a 1,3,5-triazine group, a pyridine group, a pyrimidine group, a pyridazine group, a pyrazine group, an indole group, a quinoline group, an isoquinoline group, a purine group, a tetrazole group, a tetrazine group, a triazole group, a carbazole group, an acridine group, a quinoxaline group, a quinazoline group, an indolizine group, an isoindole group, or a 3,4,5-triazine group. The group consisting of H-indole group, 2H-pyrrole group, 1H-indazole group, purine group, phthalazine group, naphthyridine group, cinnoline group, pteridine group, carboline group, phenanthridine group, perimidine group, phenanthroline group, phenazine group, phenarsazine group, phenothiazine group, furazan group, phenoxazine group, pyrrolidine group, pyrroline group, pyrazoline group, pyrazolidine group, piperidine group, piperazine group, indoline group, isoindoline group, quinuclidine group and derivatives thereof.

[0019] Among these, X1 is preferably an imidazoline group, which allows the conjugate of the present invention to be produced in high yield.

[0020] L1 is not particularly limited as a divalent group, and examples thereof include divalent hydrocarbon groups which may have a heteroatom. Examples of divalent hydrocarbon groups which may have a heteroatom include alkylene groups (preferably having 1 to 10 carbon atoms), cycloalkylene groups (preferably having 3 to 10 carbon atoms), alkenylene groups (preferably having 2 to 10 carbon atoms), alkynylene groups (preferably having 2 to 10 carbon atoms), combinations thereof, and combinations of the above with -C(O)-, -C(O)O-, -OC(O)-, -O-, -S-, and -NR2- (R2 represents a hydrogen atom or a monovalent organic group).

[0021] The silicon compound layer 110 may preferably contain at least one element selected from the group consisting of alkali metal elements, Group 2 elements, Group 3 elements, and transition metal elements. As shown in Fig. 2, the layer 110 may have a cation octahedron sheet 210 of one of these elements sandwiched between a pair of silicon-based sheets 220. Specifically, as shown in Fig. 2, the octahedron sheet 210 is made up of a series of edge-sharing octahedra each consisting of a cation of one of these elements, oxygen, and a hydroxyl group.

[0022] In this specification, the silicon-based sheet 220 refers to a material having siloxane bonds, but is preferably a polysiloxane sheet having a sheet-like shape with continuous siloxane (Si-O-Si) bonds. Examples of such polysiloxane sheets include the following two types: (1) One of the four hands of the Si atom in the siloxane bond is bonded to an organic group, and the remaining three hands are bonded to oxygen. The oxygen bonded to Si is Si-O-Si, Si-OH, or O in a cationic octahedron (sharing a corner with the cationic octahedron). (2) All four valences of the Si atoms in the siloxane bond bond with oxygen to form a Si tetrahedron. Three of the four valences are siloxane-bonded. The Si tetrahedron then forms a two-dimensional hexagonal network by corner-sharing. The remaining valence shares a corner with a cationic octahedron. These polysiloxane sheets can sandwich the octahedron sheet 210 and form a covalent bond with L1 of the organic group 120.

[0023] The polysiloxane sheet covalently bonded to the above-mentioned L1 is sometimes called an organopolysiloxane sheet.

[0024] The thickness of each layer of the layer 110 is preferably in the range of 0.5 nm to 2 nm, which allows the layer 110 to have a laminated structure in which the octahedral sheet 210 is sandwiched between a pair of silicon-based sheets 220.

[0025] The layered inorganic-organic covalent bond 101 may be represented by chemical formula (1). (M 1 x1n+ ,mH2O)(M 2 x2 M 3 x3 )R z (Si k M 4 x4 )O p (OH) q (1) M 1 is at least one element selected from the group consisting of alkali metal elements such as Li and Na, Group 2 elements such as Mg, and transition metal elements such as Ni, 2 is M 1 is an element selected from the group consisting of alkali metal elements, Group 2 elements, and transition metal elements, which is different from or identical to M 3 is M 1 and M 2 Group 2 elements, Group 3 elements such as Al, and transition metal elements, which are different from or the same as M 4 is M 1 , M 2 and M 3 R is an organic group 120, and n is at least one element selected from the group consisting of alkali metal elements, Group 2 elements, Group 3 elements, and transition metal elements, which is different from or the same as M 1 where m, x1, x2, x3, x4, z, k, p, and q satisfy 0≦m≦100, 0≦x1≦4, 0≦x2≦2, 2≦x3≦4, 0≦x4≦3, 2.2≦z≦4.5, 2≦k≦5, 9≦p≦11, and 1.5≦q≦8, respectively.

[0026] The parameters m, x1, x2, x3, x4, y, z, k, p, and q more preferably satisfy 6≦m≦12, 0.8≦x1≦1.2, 0≦x2≦0.1, 2.6≦x3≦3.4, 0≦x4≦0.1, 3.2≦z≦4, 3.2≦k≦4, 9≦p≦11, and 1.5≦q≦5, respectively, which makes the layered inorganic-organic covalent bond 101 stable.

[0027] FIG. 3 is a schematic diagram showing another layered inorganic-organic covalent bond.

[0028] The layered inorganic-organic covalent bonded material 101 may further contain metal particles 130 between the layers 110. The metal particles 130 are made of a transition metal element, and more preferably made of an element selected from the group consisting of Group 8 elements, Group 9 elements, and Group 10 elements. Because the metal particles 130 are not covered with the organic group 120, they can effectively exhibit the inherent properties of the metal.

[0029] The group 8 elements of the metal particles 130 consist of iron (Fe), ruthenium (Ru), osmium (Os), and hassium (Hs). The group 9 elements consist of cobalt (Co), rhodium (Rh), iridium (Ir), and meitnerium (Mt). The group 10 elements consist of nickel (Ni), palladium (Pd), platinum (Pt), and darmstadtium (Ds).

[0030] As long as the metal particles 130 are selected from the group of elements described above, they may consist of a single element, may be a composite metal consisting of two or more elements, or may have a core-shell structure of a metal consisting of two or more elements.

[0031] The metal particles 130 are preferably made of at least one transition metal element selected from the group consisting of Ni, Co, and Fe. These metal elements allow the metal particles 130 to be efficiently positioned between layers by the manufacturing method described below. Of these, Ni is preferred from the viewpoint of yield.

[0032] Metal particles (M NP ), the layered inorganic-organic covalent bond 101 may be represented by chemical formula (2). (M y NP )(M 1 x1 n+ ,mH2O)(M 2 x2 M 3 x3 )R z (Si k M 4 x4 )O p (OH)q (2) M NP are metal particles located between layers, and M 1 is at least one element selected from the group consisting of alkali metal elements such as Li and Na, Group 2 elements such as Mg, and transition metal elements such as Ni, 2 is M 1 is an element selected from the group consisting of alkali metal elements, Group 2 elements, and transition metal elements, which is different from or identical to M 3 is M 1 and M 2 Group 2 elements, Group 3 elements such as Al, and transition metal elements, which are different from or the same as M 4 is M 1 , M 2 and M 3 R is at least one element selected from the group consisting of alkali metal elements, Group 2 elements, Group 3 elements, and transition metal elements, which is different from or the same as R, R is an organic group 120, and n is M 1 and m, x1, x2, x3, x4, y, z, k, p, and q satisfy 0≦m≦100, 0≦x1≦3, 0≦x2≦2, 2≦x3≦3, 0≦x4≦2, 1≦y≦10, 2.2≦z≦4.5, 2≦k≦5, 9≦p≦11, and 1.5≦q≦8, respectively.

[0033] The above parameters m, x1, x2, x3, x4, y, z, k, p, and q more preferably satisfy 6≦m≦12, 0.8≦x1≦1, 0≦x2≦0.1, 2.6≦x3≦3.4, 0≦x4≦0.1, 1≦y≦6, 3.2≦z≦4, 3.2≦k≦4, 9≦p≦11, and 1.5≦q≦5, respectively. This stabilizes the layered inorganic-organic covalent bonded structure containing metal particles between the layers.

[0034] The metal particles 130 preferably have a particle size in the range of 0.5 nm to 100 nm, more preferably 1.5 nm to 50 nm, even more preferably 1.5 nm to 20 nm, and even more preferably 2 nm to 15 nm.

[0035] In this specification, the particle size of the metal particles 130 is determined by measuring the particle sizes of 100 randomly selected metal particles in an image observed with a transmission electron microscope (TEM), and taking the average particle size.

[0036] The content of the metal particles 130 is preferably in the range of more than 0 wt% to 30 wt% or less. The content of the metal particles 130 is more preferably in the range of 1 wt% to 15 wt% or less. The content of the metal particles 130 is even more preferably in the range of 3 wt% to 10 wt% or less. By controlling the content of the metal particles 130, functions based on the metal element, such as catalytic activity, plasmon luminescence, photoelectric effect, and luminescence control, can be effectively exhibited in addition to electrochromic properties. Mass percent concentration is expressed as "wt%."

[0037] The interlayer distance between the layers 110 depends on the type of organic group 120, but is illustratively in the range of 7 Å to 50 Å. Within this range, intercalation of the metallo-supramolecular polymer 103 between the layers 110 can be suppressed.

[0038] The interlayer distance can be increased by selecting an organic group having a bulky group such as a long-chain alkyl group as the organic group 120, and the interlayer distance can be decreased by selecting the opposite organic group. The interlayer distance can also be controlled by controlling the composition ratio of the organic group 120. For example, the interlayer distance increases when the composition ratio of the organic group 120 (z in the above chemical formula) is large.

[0039] The organic ligand in the metallo-supramolecular polymer 103 is not particularly limited as long as it is an organic compound that can coordinate a metal ion and can be polymerized by alternately linking the metal ion and the organic ligand through a bonding form that includes at least one type selected from the group consisting of a coordinate bond and an organometallic bond. The organic ligand is preferably selected from the group consisting of a terpyridine group, a phenanthroline group, a bipyridine group, an imino group, and derivatives thereof. The organic ligand constituting the metallo-supramolecular polymer may be of a single type or of multiple types. When these organic ligands coordinate with the metal ion to form a complex, the organic ligand and the metal ion are alternately linked to form the metallo-supramolecular polymer.

[0040] The terpyridine group is typically 2,2':6',2"-terpyridine, but may be a derivative having various substituents. Exemplary substituents include a halogen atom, a hydrocarbon group, a hydroxyl group, an alkoxy group (e.g., C1 to C 10 ), carbonyl group, carboxylic acid ester group (e.g., C1-C 10 ), amino group, substituted amino group, amido group, substituted amido group, cyano group, nitro group, etc. Examples of the hydrocarbon group include C1 to C 10 Specific examples include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a t-butyl group, etc. Furthermore, examples of substituents that these substituents may have include C1 to C4 groups such as a methyl group, an ethyl group, and a hexyl group. 10 C1-C alkyl groups, methoxy groups, butoxy groups, etc. 10 Examples of the substituents include, but are not limited to, alkoxy groups of the formula (I) and halogen atoms such as chlorine and bromine.

[0041] The bipyridine group may be 2,2'-bipyridine, 3,3'-bipyridine, 4,4'-bipyridine, 2,3'-bipyridine, 2,4'-bipyridine, or 3,4'-bipyridine, or may be a derivative having various substituents, where again, exemplary substituents are as described above.

[0042] The imino group has a C═N and can be a derivative having various substituents. Exemplary substituents that the derivatives can have are as described above.

[0043] The phenanthroline group is a phenanthrene in which any two carbon atoms are replaced with nitrogen atoms, and may be a derivative having various substituents. Exemplary substituents that the derivative may have include, but are not limited to, a methyl group, a t-butyl group, a phenyl group, a thienyl group, a bithienyl group, a terthienyl group, and a phenylacetyl group.

[0044] The metal ion may be any metal ion that changes valence through a redox reaction, but is preferably at least one metal ion selected from the group consisting of Pt, Cu, Ni, Pd, Ag, Mo, Fe, Co, Ru, Rh, Eu, Zn, Os, Cr, and Mn. These metal ions coordinate with the organic ligands described above. More preferably, when the organic ligand is a terpyridine group or a derivative thereof, a hexacoordinated metal ion is selected, and when the organic ligand is a phenanthroline group, a bipyridine group, an imino group, or a derivative thereof, a tetracoordinated metal ion is selected.

[0045] The metallo-supramolecular polymer 103 is preferably represented by a general formula selected from the group consisting of general formulas (I), (II) and (III). The metallo-supramolecular polymer 103 may be a mixture thereof.

[0046] [ka]

[0047] The metallo-supramolecular polymers represented by formula (I) and formula (II) each contain a terpyridine group or its derivative as an organic ligand and a metal ion coordinated thereto. The metallo-supramolecular polymer represented by formula (III) contains a phenanthroline group or its derivative as an organic ligand and a metal ion coordinated thereto.

[0048] In formula (I), M represents a metal ion, X represents a counter anion, S represents a spacer containing a carbon atom and a hydrogen atom or a spacer directly connecting two terpyridine groups, and R 1 ~R 4 each independently represents a hydrogen atom or a substituent, and n is an integer of 2 or more that represents the degree of polymerization.

[0049] In formula (II), M 1 ~M N (N is an integer of 2 or more) each independently represents a metal ion having a different redox potential, and X 1 ~X n (n is an integer of 2 or more) each independently represents a counter anion, and S 1 ~S N (N is an integer of 2 or more) each independently represent a spacer containing a carbon atom and a hydrogen atom or a spacer directly connecting two terpyridine groups, and R 1 1~R 1 N , R 2 1~R 2 N , R 3 1~R 3 N , R 4 1~R 4 N (N is an integer of 2 or more) each independently represents a hydrogen atom or a substituent, and n 1 ~n N are each independently an integer of 2 or more indicating the degree of polymerization.

[0050] Here, the metal ion in formula (I) and formula (II) may be at least one metal ion selected from the group consisting of Fe, Co, Ni, Zn, Ru, Os, Cr, and Rh. These metal ions can be in a hexacoordinated form, which allows them to form a complex with the organic ligand.

[0051] The counter anions in formula (I) and formula (II) may be selected from the group consisting of acetate, phosphate, chloride, phosphorus hexafluoride, boron tetrafluoride, and polyoxometalates, which render the metallo-supramolecular polymer 103 electrically neutral and stable.

[0052] When the spacer in Formula (I) or Formula (II) contains carbon and hydrogen atoms, the spacer may be a divalent organic group containing carbon and hydrogen atoms. Examples include aliphatic hydrocarbon groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and heterocyclic groups. Among these, arylene groups such as phenylene and biphenylene are preferred. These hydrocarbon groups may also contain substituents such as alkyl groups (e.g., methyl, ethyl, and hexyl), alkoxy groups (e.g., methoxy and butoxy), and halogen atoms (e.g., chlorine and bromine). These spacers may also contain oxygen or sulfur atoms. Oxygen and sulfur atoms have modifying properties, making them advantageous for material design of metallo-supramolecular polymer 103.

[0053] Among the divalent arylene groups, the following arylene groups are preferred, as these stabilize the metallo-supramolecular polymer 103.

[0054] [ka]

[0055] Examples of the aliphatic hydrocarbon group constituting the spacer include alkylene groups of C1 to C6, specifically methylene, ethylene, n-propylene, i-propylene, n-butylene, t-butylene, etc. Furthermore, the divalent organic group constituting the spacer may be one having a substituent such as a C1 to C6 alkyl group such as a methyl group, an ethyl group, or a hexyl group, a C1 to C6 alkoxy group such as a methoxy group or a butoxy group, or a halogen atom such as chlorine or bromine.

[0056] R in formula (I)1 ~R 4 and R of formula (II) 1 1~R 1 N , R 2 1~R 2 N , R 3 N ~R 3 N , R 4 1~R 4 N each independently represents a hydrogen atom or a substituent, and examples of the substituent include a halogen atom, a hydrocarbon group, a hydroxyl group, an alkoxy group (e.g., C1 to C 10 ), carbonyl group, carboxylic acid ester group (e.g., C1-C 10 ), amino group, substituted amino group, amido group, substituted amido group, cyano group, nitro group, etc. Examples of the hydrocarbon group include C1 to C 10 Examples of the substituents that may be substituted by these hydrocarbon groups include C1-C alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, and t-butyl. 10 C1-C alkyl groups, methoxy groups, butoxy groups, etc. 10 The alkyl group may have a substituent such as an alkoxy group or a halogen atom such as chlorine or bromine, but is not limited to these.

[0057] In formula (I), n is an integer of 2 or more indicating the degree of polymerization, for example, 2 to 5000, preferably 10 to 1000. In formula (II), n 1 ~n N are each independently an integer of 2 or more indicating the degree of polymerization, and the sum of n 1 +n 2 +n N is, for example, 2 to 5,000, preferably 10 to 1,000.

[0058] In formula (III), M represents a metal ion, X represents a counter anion, A represents a spacer containing a carbon atom and a hydrogen atom or a spacer directly connecting two phenanthroline groups, and R 1 ~R 4 each independently represents a hydrogen atom or a substituent, and n is an integer of 2 or more that represents the degree of polymerization.

[0059] Here, the metal ion in formula (III) can be at least one metal ion selected from the group consisting of Pt, Cu, Ni, Ag, and Pd. These metal ions can be in a tetracoordinated form, allowing them to form complexes with the organic ligands. The counter anion in formula (III) can be selected from the group consisting of perchlorate ions, triflate ions, boron tetrafluoride ions, chloride ions, and hexafluorophosphate ions. These counter anions make the metallo-supramolecular polymer 103 electrically neutral and stabilized.

[0060] When the spacer in formula (III) contains carbon atoms and hydrogen atoms, typical examples of the spacer include phenyl, biphenyl, terphenyl, thienyl, bithienyl, and terthienyl groups, as shown below. To enhance the solubility of the bis(phenanthroline) derivative, it is also desirable to use a spacer modified with an alkyl group (having 1 to 16 carbon atoms) or an alkoxy group (having 1 to 16 carbon atoms). Furthermore, a spacer in which phenyl groups are linked by a dioxoalkyl group (having 2 to 16 carbon atoms) can also be used.

[0061] [ka]

[0062] R in formula (III) 1 and R 2 As shown below, R in formula (III) includes hydrogen, a methyl group, a t-butyl group, a phenyl group, a thienyl group, a bithienyl group, and a terthienyl group. 3 and R 4Examples of the alkyl group include hydrogen, a phenyl group, and a phenylacetyl group.

[0063] [ka]

[0064] In formula (III), n is an integer of 2 or more indicating the degree of polymerization, for example, 2 to 5,000, and preferably 10 to 1,000.

[0065] The metallo-supramolecular polymer 103 exhibits color based on charge transfer absorption from metal ions to organic ligands. That is, when the metallo-supramolecular polymer 103 is electrochemically oxidized, it loses its color and becomes colorless, and when it is electrochemically reduced, it becomes colored. This phenomenon can be repeated. Therefore, such metallo-supramolecular polymer 103 exhibits electrochromic properties.

[0066] In the composite particle 100 of the present invention, the mass ratio of the metallo-supramolecular polymer 103 to the particles 102 is preferably in the range of 0.1 or more and 40 or less. Within this range, the metallo-supramolecular polymer 103 coats the particles 102, promoting stabilization of the redox potential of the metallo-supramolecular polymer 103. The mass ratio of the metallo-supramolecular polymer 103 to the particles 102 is more preferably in the range of 0.6 or more and 30 or less. Within this range, the stabilization of the redox potential of the metallo-supramolecular polymer 103 is further promoted. The mass ratio of the metallo-supramolecular polymer 103 to the particles 102 is even more preferably in the range of 0.6 or more and 5 or less. Within this range, the stabilization of the redox potential of the metallo-supramolecular polymer 103 is further promoted, resulting in a significant improvement in memory retention characteristics.

[0067] The particle size (D50) of the composite particle 100 of the present invention is preferably in the range of 0.5 nm to 35 μm. This range facilitates the production of an electrochromic layer in an electrochromic device. The particle size is more preferably in the range of 0.3 μm to 30 μm, and even more preferably in the range of 1.5 μm to 22 μm.

[0068] The surface of the composite particle 100 of the present invention is smooth because it is coated with the metallo-supramolecular polymer 103. If a particle with a smooth surface is observed under an electron microscope, it can be easily determined that the composite particle 100 of the present invention has been obtained.

[0069] FIG. 4 is a flow chart showing the steps for producing the composite particles of the present invention.

[0070] Step S410: A particle dispersion is prepared in which particles of a layered inorganic-organic covalently bonded material in which a silicic acid compound and an organic group are covalently bonded are dispersed. Such layered inorganic-organic covalently bonded materials are as described above, and therefore further explanation is omitted. The layered inorganic-organic covalently bonded material can be produced, for example, by the following steps A and B, and optionally C:

[0071] Step A: A salt or hydroxide of at least one element selected from the group consisting of alkali metal elements, Group 2 elements, Group 3 elements, and transition metal elements is mixed with a silicon-containing organic substance.

[0072] Step B: The mixture obtained in Step A is subjected to hydrothermal synthesis. Hydrothermal synthesis refers to the synthesis of a compound carried out in the presence of hot water in a sealed container. An existing autoclave reactor or hydrothermal synthesis reaction apparatus can be used for the hydrothermal synthesis. This results in the layered inorganic-organic covalent bonded compound 101 represented by chemical formula (1).

[0073] Step C: The product obtained in Step B is irradiated with an electron beam. This allows metal particles to grow in the product. This results in a layered inorganic-organic covalent bonded material 101 represented by chemical formula (2).

[0074] Each step will be described in detail. In step A, the salt or hydroxide of at least one element selected from the group consisting of alkali metal elements, Group 2 elements, Group 3 elements, and transition metal elements is not particularly limited, but specifically includes acetates, sulfates, nitrates, carbonates, chlorides, etc. of the selected element.

[0075] In step A, the silicon-containing organic material is not limited as long as it has silicon and an organic group represented by X1-L1, but preferably, silicon is bonded to L1. This promotes the formation of an inorganic compound layer. X1 is a functional group selected from the group consisting of heterocyclic groups, amine groups, amide groups, thioether groups, sulfonic groups, nitro groups, carboxyl groups, vinyl groups, SH groups, alkyl groups, hydrogen, and derivatives thereof, and L1 is a divalent group. X1 and L1 are as described above, so further explanation is omitted.

[0076] When X1 is an imidazoline group, the organic substance may be, for example, triethoxy-3-(2-imidazolin-1-yl)propylsilane, trimethoxy-3-(2-imidazolin-1-yl)propylsilane, trialkoxy-3-(2-imidazolin-1-yl)propylsilane, trialkoxy-3-(2-imidazolin-1-yl)alkylsilane, trialkoxy-2-methyl-2-imidazoline-propylsilane, trialkoxy-2-phenyl-2-imidazoline-propylsilane, etc. If these are used, the layered inorganic-organic covalently bonded particles made of the layered silicate compound can be obtained in high yield.

[0077] In step A, a salt or hydroxide of a metal element and a silicon-containing organic substance are mixed in a molar ratio of metal element salt or hydroxide:silicon-containing organic substance = 3:2.5 to 3:5. This promotes the formation of particles of the layered inorganic-organic covalently bonded material represented by the above-mentioned chemical formula (1) by hydrothermal synthesis, which will be described later, together with the salt or hydroxide of the metal element.

[0078] In step A, the raw materials may be mixed with a dispersion medium such as distilled water, Milli-Q (registered trademark MILLI-Q) water, deionized water, or ultrapure water, or in step S420, the mixture may be dispersed in a dispersion medium and subjected to hydrothermal synthesis.

[0079] The dispersion medium may contain alcohols such as methanol and ethanol, organic solvents such as toluene, hexane, and benzene, acids such as hydrochloric acid and nitric acid, and bases such as ammonia and sodium hydroxide. This can promote and control the synthesis reaction. The amount of these added is in the range of 0.0001 wt% to 95 wt%.

[0080] In step B, the hydrothermal synthesis is preferably carried out by heating the mixture in a temperature range of 20°C to 200°C. This range can promote the reaction. Preferably, the mixture is heated in a temperature range of 80°C to 200°C, more preferably 140°C to 200°C. This can further promote the reaction. The heating time is not particularly limited, but is between 1 hour and 10 days. If the heating time is less than 1 hour, the reaction may be insufficient and the yield may be low. Heating for more than 10 days is inefficient because the reaction does not proceed any further. Preferably, the heating time is between 10 hours and 7 days.

[0081] In step C, the electron beam is preferably irradiated to the product at an acceleration voltage of 1 kV to 200 kV and a current of 10 pA to 10 mA. This can promote the growth of metal particles. More preferably, the electron beam is irradiated at an acceleration voltage of 50 kV to 150 kV and a current of 50 pA to 200 pA. Even more preferably, the electron beam is irradiated at an acceleration voltage of 75 kV to 125 kV and a current of 70 pA to 110 pA. Any device equipped with an electron beam source can be used for electron beam irradiation, and examples include an electron beam irradiation device, a transmission electron microscope, a scanning electron microscope, etc.

[0082] Return to Figure 4 again. In step S410, the dispersion medium of the particle dispersion is selected from the group consisting of methanol, ethanol, and water. These dispersion mediums do not exfoliate or swell the particles of the layered inorganic-organic covalent bonded structure, and therefore can effectively prevent the metallo-supramolecular polymer from intercalating between the particle layers in step S420 described below.

[0083] In step S410, the particle concentration in the particle dispersion is preferably in the range of 0.05 mg / mL to 10 mg / mL. This range allows the particles to be well dispersed in the particle dispersion, facilitating the coating of the metallo-supramolecular polymer on the particle surfaces. The particle concentration in the particle dispersion is more preferably in the range of 0.1 mg / mL to 5 mg / mL, and even more preferably in the range of 1 mg / mL to 5 mg / mL. This stabilizes the redox potential, providing composite particles with excellent memory retention.

[0084] Step S420: A polymer solution containing a metallo-supramolecular polymer is prepared. Such metallo-supramolecular polymers are as described above, and therefore, a detailed description thereof will be omitted. For example, the metallo-supramolecular polymer may be an organic / metal hybrid polymer (metallo-supramolecular polymer) synthesized with reference to Patent Documents 1 and 2.

[0085] In step S420, the solvent of the polymer solution is not particularly limited as long as it has affinity with the dispersion medium of the particle dispersion in step S410 described later and dissolves the metallo-supramolecular polymer, but is preferably selected from the group consisting of methanol, ethanol, propanol, isopropanol, butanol, acetone, and water. More preferably, the same solvent as the dispersion medium in step S410 is selected.

[0086] In step S420, the metallo-supramolecular polymer concentration in the polymer solution is preferably in the range of 2 mg / mL to 4 mg / mL. This range allows the metallo-supramolecular polymer to be well dispersed in the metallo-supramolecular polymer, facilitating the coating of the metallo-supramolecular polymer on the particle surface. The metallo-supramolecular polymer concentration in the polymer solution is more preferably in the range of 2.5 mg / mL to 3.5 mg / mL. This stabilizes the redox potential, providing composite particles with excellent memory retention.

[0087] Step S430: The particle dispersion obtained in step S410 and the polymer solution obtained in step S420 are mixed and stirred. This is advantageous because the composite particles of the present invention can be obtained simply by mixing and stirring.

[0088] The mixing is preferably carried out so that the mass ratio of the metallo-supramolecular polymer to the particles is preferably in the range of 0.1 to 40. This can promote the coating of the particles with the metallo-supramolecular polymer. More preferably, the mass ratio of the metallo-supramolecular polymer to the particles is in the range of 0.6 to 30, and even more preferably in the range of 0.6 to 5. This stabilizes the redox potential and can provide composite particles with excellent memory retention properties.

[0089] The stirring is not particularly limited, but may be performed, for example, at room temperature (a temperature range of 15° C. to 30° C.) for 12 to 36 hours. Stirring may be performed using a stirring bar such as a magnetic stirrer.

[0090] Step S440: The solvent is removed from the mixture obtained in step S430. There are no particular limitations on how the solvent is removed, but for example, it may be removed in the atmosphere at a temperature ranging from 15°C to 50°C for 12 hours to 48 hours. This removes the unnecessary solvent, and the composite particles of the present invention are obtained.

[0091] The order of steps S410 and S420 does not matter. Furthermore, prior to step S440, the mixed solution may be applied to a substrate or the like. This provides a thin film made of the composite particles of the present invention. Any method, such as spin coating, casting, spraying, or printing, may be used for application.

[0092] (Embodiment 2) In the second embodiment, an electrochromic device will be described in which the composite particles of the present invention described in the first embodiment are used in an electrochromic layer.

[0093] FIG. 5 is a schematic diagram showing an electrochromic device of the present invention.

[0094] 5 includes a first electrode 510, an electrochromic layer 520 positioned on the first electrode 510, an electrolyte layer 530 positioned on the electrochromic layer 520, and a second electrode 540 positioned on the electrolyte layer 530. Here, the electrochromic layer 520 contains the composite particles of the present invention described in the first embodiment.

[0095] At least one of the first electrode 510 and the second electrode 540 may be any transparent electrode, but the electrode material is preferably an SnO2 film, an In2O3 film, or an ITO film, which is a mixture of In2O3 and SnO2. The first electrode 510 and the second electrode 540 can be obtained by forming a transparent electrode material such as ITO on a transparent substrate, such as a resin substrate (e.g., plastic) or a glass substrate, by any physical vapor deposition method or chemical vapor deposition method.

[0096] The electrochromic layer 520 contains the composite particles of the present invention explained in the first embodiment as described above, and the explanation of the composite particles of the present invention will be omitted.

[0097] The electrolyte layer 530 contains at least a polymer and a supporting salt. Preferably, the electrolyte layer 530 contains a plasticizer selected from the group consisting of propylene carbonate (PC), ethylene carbonate, dimethyl carbonate, diethylene carbonate, γ-butyrolactone, and succinonitrile. This allows the plasticizer and supporting salt to exist in the polymer network, forming a gel electrolyte layer, and thus providing a flexible electrochromic device.

[0098] More preferably, the electrolyte layer 530 is fabricated by dissolving the polymer and supporting salt in a solvent selected from the group consisting of acetonitrile, acetone, and tetrahydrofuran, casting the solution, and then removing the solvent. This results in a gel electrolyte layer in which the polymer, plasticizer, and supporting salt are uniformly dispersed, leading to improved and stabilized electrochromic device characteristics.

[0099] The polymer is preferably selected from the group consisting of polymethyl methacrylate (PMMA), polyethylene oxide (PEO), poly(vinylidene fluoride-co-hexafluoroisopropyl) (PVdF-co-PHFP), polypropylene carbonate (PPC), polycarbonate, and polyacrylonitrile, which are advantageous for forming the gel electrolyte layer.

[0100] The supporting salt is preferably selected from the group consisting of LiClO4, LiBF4, LiAsF6, LiPF6, LiCF3SO3, LiCF3COO, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), LiCH3COO, tetrabutylammonium perchlorate, tetraethylammonium perchlorate, KCl, NaClO3, NaCl, NaBF4, NaSCN, KBF4, Mg(ClO4)2, and Mg(BF4)2. These supporting salts effectively function as counter anions for the metallo-supramolecular polymer in the composite particles of the present invention.

[0101] The electrochromic device 500 of the present invention may be sealed with a sealant made of epoxy resin and / or silicone resin, which improves the barrier properties of the electrochromic device 500 against oxygen and water.

[0102] The electrochromic device 500 of the present invention operates as follows: The first electrode 510 and the second electrode 540 are connected to a power source (not shown), and a predetermined voltage is applied to the electrochromic layer 520 and the electrolyte layer 530. This allows the oxidation-reduction of the electrochromic layer 520 to be controlled. That is, the oxidation-reduction of the metal ions of the metallo-supramolecular polymer in the composite particle of the present invention that constitutes the electrochromic layer 520 is controlled, allowing coloring and decoloring to occur.

[0103] Here, since the electrochromic layer 520 contains the composite particles of the present invention, an electrochromic device 500 is provided that operates at a low operating voltage and has excellent memory characteristics. Improved memory characteristics are expected to lead to power savings.

[0104] The electrochromic device 500 of the present invention is manufactured by forming an electrochromic layer 520 (FIG. 5) containing at least the composite particles of the present invention described in embodiment 1 on a first electrode 510 (FIG. 5), and then forming an electrolyte layer 530 (FIG. 5) and a second electrode 540 (FIG. 5) thereon.

[0105] The present invention will now be described in detail using specific examples, but it should be noted that the present invention is not limited to these examples. [Example]

[0106] [Synthesis of Metallo-Supramolecular Polymers] The metallo-supramolecular polymer used was a polymer material represented by the following formula: The polymer material was manufactured by Tokyo Chemical Industry Co., Ltd. with reference to Patent Document 1 or F.S.Han et al., J.Am.Chem.Soc., 2008, 130(6), pp. 2073-2081. Hereinafter, for simplicity, the metallo-supramolecular polymer may be referred to as polyFe.

[0107] [ka]

[0108] [Synthesis of layered inorganic-organic covalently bonded particles in which silicate compounds and organic groups are covalently bonded] The layered inorganic-organic covalently bonded particles were prepared as follows: First, nickel acetate and triethoxy-3-(2-imidazolin-1-yl)propylsilane were mixed in a molar ratio of 3:4, and hydrothermal synthesis was carried out at 170°C for 6 days using a hydrothermal synthesis apparatus.

[0109] The composition of the obtained sample was analyzed using an optical emission spectrometer (ICP-OES, Hitachi High-Tech Science, SPS3520UV-DD), and was found to be expressed by the following formula. (M 1 x1 n+ ,mH2O)(M 2 x2 M 3 x3 )R z (Si k M 4 x4 )O p (OH) q where M 1 , M 2 , M 3 and M 4is Ni, R is an organic group (here, triethoxy-3-(2-imidazolin-1-yl)propylsilane), n is 2, and m, x1, x2, x3, x4, z, k, p, and q satisfy the following relationships: 0≦m≦12, x1=0.9, x2=0, x3=3, x4=0, z=3.5, k=3.5, 9≦p≦11, and 1.5≦q≦5, respectively.

[0110] When the obtained sample was subjected to X-ray diffraction (XRD, Rigaku RINT-2200HF), multiple peaks were observed on the low-angle side, and the d value of the peak appearing at the lowest angle corresponded to the interlayer distance, which was 19 Å.

[0111] Observation was carried out using a field emission scanning electron microscope (SEM, JSM-6500F, manufactured by JEOL Ltd.) and the results are shown in Figure 6.

[0112] FIG. 6 shows an SEM image of a particle of a layered inorganic-organic covalent bonded material.

[0113] Figure 6 shows that the particles are layered. From the SEM image, 1,000 particles that were not overlapping were randomly selected, and their particle sizes were measured using Image J (ver. 1.51n; open-source, public-domain image processing software). Next, the volume of the particles was calculated from the obtained particle size, assuming they were spherical. The volume-cumulative particle size (D50, median diameter) at 50% of the cumulative volume was calculated, and found to be 100 μm.

[0114] The obtained particles of the layered inorganic-organic covalent bonded material were irradiated with an electron beam using a transmission electron microscope (TEM, JEOL, JEM-1010) (accelerating voltage 100 kV, current 90 pA, irradiation time 60 seconds), and the generation of Ni particles was confirmed by SAD patterns and TEM images. In Examples 1 to 5, particles of the layered inorganic-organic covalent bonded material before electron beam irradiation were used.

[0115] [Example 1 to Example 5] For Examples 1 to 4, samples were prepared as follows. Particles of a layered inorganic-organic covalent bonded structure were dispersed in methanol as a dispersion medium to prepare particle dispersions with various concentrations shown in Table 1 (Step S410 in FIG. 4). A metallo-supramolecular polymer (polyFe) was dissolved in methanol to prepare polymer solutions with various concentrations shown in Table 1 (Step S420 in FIG. 4). Next, the particle dispersion and polymer solution were mixed to satisfy the mass ratios shown in Table 1 and stirred at room temperature for 24 hours using a magnetic stirrer (Step S430 in FIG. 4). After the mixed solutions were obtained, the solvent was dried from some of the solutions, and powder samples were obtained. Other solutions were cast onto substrates, and the solvent was dried to obtain thin film samples (Step S440 in FIG. 4). The substrates used were ITO substrates (glass substrates coated with indium tin oxide (ITO), resistivity = 8 to 12 Ω / cm, 2.5 cm × 2.5 cm, manufactured by Igma-Aldrich Co. LLC).

[0116] Example 5 was the same as Examples 1 to 4, except that no layered inorganic-organic covalent bonded material particles were used.

[0117] [Table 1]

[0118] The powder sample was subjected to SEM imaging and XRD analysis. The median diameter (D50) was calculated from the SEM image using Image J. The results are shown in Table 2 and Figures 7 to 9.

[0119] FIG. 7 is a diagram showing an SEM image of the sample of Example 1. FIG. 8 is a diagram showing an SEM image of the sample of Example 2. FIG. 9 is a diagram showing an SEM image of the sample of Example 3.

[0120] Comparing Figures 7 to 9 with Figure 6, the surfaces of the samples in Examples 1 to 3 were all smoother than those of the layered inorganic-organic covalent bond particles. This indicates that the surfaces of the layered inorganic-organic covalent bond particles were coated with a metallo-supramolecular polymer. According to Table 2, the samples in Examples 1 to 4 had particle sizes (D50) ranging from 0.3 μm to 30 μm. The smaller particle sizes than those of the layered inorganic-organic covalent bond particles used as raw materials are believed to be due to the destruction of aggregated or stacked higher-order particles during stirring during preparation. Furthermore, the XRD patterns (not shown) of the samples in Examples 1 to 4 were similar to those of the layered inorganic-organic covalent bond particles, with d values of 19 Å in all cases. Although not shown, smooth surfaces were also confirmed when the layered inorganic-organic covalent bond particles after electron beam irradiation were used, similar to those in Examples 1 to 3.

[0121] [Table 2]

[0122] From the above, it was found that the samples of Examples 1 to 4 are composite particles containing particles of a layered inorganic-organic covalent bond and a metallo-supramolecular polymer coating the particles, and that the metallo-supramolecular polymer is not intercalated between the layers of the layered inorganic-organic covalent bond particles.

[0123] Next, the operating potentials of the samples of Examples 1 to 5 were measured using a cyclic voltammogram measurement device CV50W (manufactured by BAS, Japan). The working electrode for the measurement was prepared by dropping 20 μl of methanol containing a dispersion of each of the samples of Examples 1 to 5 (1 mg, 0.5 ml) onto a glassy carbon electrode and drying it. A Pt counter electrode was used as the counter electrode, Ag / Ag+ as the reference electrode, and ACN / TBAP (tetrabutylammonium perchlorate) as the electrolyte solution. All electrodes were manufactured by BAS. A potential was applied in the range of 0 to 1.5 V vs. Ag / Ag+, and the potential sweep rate was 0.1 V / s. The results are shown in Figure 10. The redox potential was calculated from Figure 10. The results are shown in Figure 11.

[0124] FIG. 10 shows cyclic voltammograms of the samples of Examples 1 to 3 and Example 5. As shown in FIG. FIG. 11 is a diagram showing the oxidation-reduction potentials of the samples of Examples 1 to 3 and Example 5 calculated from FIG.

[0125] 10 and 11, the redox potential (E / 2) of the samples of Examples 1 to 3 was smaller than that of Example 5, and it was found that the operating voltage was reduced. It was found that the redox potential can be stabilized by controlling the composition. Although not shown, when particles of the layered inorganic-organic covalent bonded material after electron beam irradiation were used, a reduction in operating voltage was confirmed, similar to Examples 1 to 3.

[0126] [Table 3]

[0127] Next, an electrochromic device 500 (FIG. 5) was manufactured using the thin films (electrochromic layer 520 in FIG. 5) of Examples 1 to 5 formed on an ITO substrate (first electrode 510 in FIG. 5), and the electrochromic properties were examined. Note that although particles were observed to be dispersed in the thin films of Examples 1 to 4, they were uniform layers.

[0128] Specifically, the electrochromic device was fabricated as follows. An electrolyte layer 530 (Figure 5) was formed on another ITO substrate (2.5 cm × 2.5 cm) as a second electrode 540 (Figure 5). Lithium perchlorate (LiClO4, manufactured by Kanto Chemical Co., Inc.) was dissolved in acetonitrile (ACN, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and poly(methyl methacrylate) (PMMA, weight-average molecular weight = 350 kg / mol, manufactured by Sigma-Aldrich Co. LLC.) was added. The mixture was vigorously stirred until the PMMA was completely dissolved, yielding an electrolyte material. This electrolyte material was a colorless, transparent, semi-gel-like viscous liquid. The weight ratio of PMMA to LiClO4 to ACN was 7:3:27:70. This electrolyte material was applied to another ITO electrode by drop casting to form an electrolyte layer.

[0129] Next, an ITO electrode was attached so that the electrochromic layer and the electrolyte layer faced each other, and the resulting mixture was left at room temperature for 72 hours to remove the insoluble solvent, thereby obtaining an electrochromic device 500 (FIG. 5).

[0130] While applying a predetermined voltage (-3 to 3 V) to the electrochromic device, the ultraviolet-visible absorption spectrum was measured in the wavelength range of 300 nm to 900 nm using a UV-VIS spectrometer (UV2600, Shimadzu, Japan) in transmission mode. The results are shown in Figure 12(A) and Figure 13(A).

[0131] Next, the electrochromic properties of the obtained electrochromic device were investigated. A voltage was applied to the obtained electrochromic device, and the change in color was confirmed. The results are shown in Figure 12(B) and Figure 13(B).

[0132] The memory characteristics of the obtained electrochromic device were investigated under closed and open circuits. After applying a voltage (+3.0 V), the relationship between the change in transmittance and time after the voltage was removed was investigated. The results are shown in Figures 14 and 15 and Table 4.

[0133] FIG. 12 shows the change in transmittance (A) and the change in color (B) of the electrochromic device of Example 3. FIG. 13 shows the change in transmittance (A) and the change in color (B) of the electrochromic device of Example 5.

[0134] According to Figures 12(A) and 13(A), in the reduced state (when no voltage is applied), there is an absorption peak at a wavelength of 584.6 nm, but in the oxidized state (when a voltage of +0.75 V is applied), this peak disappears. This is because the iron ions in polyFe are Fe 2+ From Fe 3+This is because, as shown in Figures 12(B) and 13(B), in the reduced state, a purple color was developed (left panels of Figures 12(B) and 13(B)). When a voltage ranging from 0 V to +3 V was applied to the electrochromic device and swept, an oxidation reaction occurred at the point where +0.75 V was applied, and the purple color disappeared, becoming colorless (right panels of Figures 12(B) and 13(B)). Thus, the development and disappearance of color were confirmed visually. Although not shown, the electrochromic devices of Examples 1, 3, and 4 also showed similar changes. This is a characteristic based on the metallo-supramolecular polymer (here, polyFe), and it was demonstrated that composite particles in which layered inorganic-organic covalently bonded particles are coated with a metallo-supramolecular polymer can maintain the electrochromic properties of the metallo-supramolecular polymer.

[0135] Note that Figures 12 and 13 are shown in grayscale, and the areas with dark contrast in the left images of Figures 12(B) and 13(B) correspond to purple coloring, while the areas with bright contrast in the right images correspond to areas where the purple coloring has faded and become colorless.

[0136] FIG. 14 is a graph showing the memory characteristics of the electrochromic device of Example 3. FIG. 15 is a graph showing the memory characteristics of the electrochromic device of Example 5.

[0137] 14(A) and 15(A) show the memory characteristics of a closed-circuit electrochromic device, and FIG. 14(B) and 15(B) show the memory characteristics of an open-circuit electrochromic device.

[0138] 14 and 15, it is surprising that the memory characteristics of the electrochromic device of Example 3 were significantly improved in both open and closed circuits compared to those of the electrochromic device of Example 5. As shown in Table 4, the memory characteristics of the electrochromic devices of Examples 1 and 4 were also improved.

[0139] [Table 4]

[0140] As explained above, composite particles containing particles of the layered inorganic-organic covalent bonded body of the present invention in which a silicic acid compound and an organic group are covalently bonded, and a metallo-supramolecular polymer coating the particles, can maintain the electrochromic properties of the metallo-supramolecular polymer, and in particular stabilize the redox potential. Therefore, it has been shown that by using such composite particles in the electrochromic layer, it is possible to provide an electrochromic device with improved memory properties and energy savings. [Industrial Applicability]

[0141] The composite particles of the present invention exhibit electrochromism at a low operating voltage and have excellent memory properties, and therefore can be used in any device that utilizes their coloring and decoloring properties, and specifically can be applied to display elements, light control elements, and electronic paper. [Explanation of symbols]

[0142] 100 composite particles 101 Layered inorganic-organic covalent bond 102 particles 103 Metallo-supramolecular polymers 110 Silicon Compound Layer 120 Organic group 130 Metal particles 210 cation octahedral sheet 220 Silicon-based sheet 500 Electrochromic Devices 510 first electrode 520 Electrochromic Layer 530 Electrolyte layer 540 Second electrode

Claims

1. Particles of a layered inorganic-organic covalent bonded material in which a layered silicate compound and an organic group are covalently bonded; a metallo-supramolecular polymer coating the particles; Contains The organic group is represented by X1-L1, X1 is a functional group selected from the group consisting of a heterocyclic group, an amine group, an amide group, a thioether group, a sulfone group, a nitro group, a carboxyl group, a linear or branched alkyl group, a linear or branched alkylamine group (including primary, secondary, and tertiary groups), a linear or branched quaternary alkylammonium group, a quaternary arylammonium group, coumarin, and derivatives thereof; L1 is a divalent group, The metallo-supramolecular polymer comprises, as repeating units, an organic ligand and a metal ion coordinated to the organic ligand.

2. The composite particle according to claim 1 , wherein the mass ratio of the metallo-supramolecular polymer to the particle is in the range of 0.1 to 40.

3. The composite particle according to claim 2 , wherein the mass ratio of the metallo-supramolecular polymer to the particle is in the range of 0.6 to 30.

4. 4. The composite particle according to claim 1, wherein X1 is an imidazoline group.

5. The composite particle according to any one of claims 1 to 4, wherein the layered inorganic-organic covalent bonded material is represented by chemical formula (1): (M １ ｘ１ ｎ＋ ,mH ２ O)(M ２ ｘ２ M ３ ｘ３ )R ｚ (Si ｋ M ４ ｘ４ )O ｐ (OH) ｑ (1) Here, M １ is at least one element selected from the group consisting of alkali metal elements, Group 2 elements, and transition metal elements, and M ２ is the M １ is an element selected from the group consisting of alkali metal elements, Group 2 elements, and transition metal elements, which is different from or the same as M ３ is the M １ and the M ２ Group 2 elements, Group 3 elements and transition metal elements, which are different from or identical to M ４ is the M １ , said M ２ and the M ３ is at least one element selected from the group consisting of alkali metal elements, Group 2 elements, Group 3 elements, and transition metal elements, which is different from or the same as M 1 and m, x1, x2, x3, x4, z, k, p, and q satisfy 0≦m≦100, 0≦x1≦4, 0≦x2≦2, 2≦x3≦4, 0≦x4≦3, 2.2≦z≦4.5, 2≦k≦5, 9≦p≦11, and 1.5≦q≦8, respectively.

6. 5. The composite particle according to claim 1, wherein the layered inorganic-organic covalent bonded material contains metal particles between layers.

7. The composite particle according to claim 6, wherein the layered inorganic-organic covalent bond is represented by chemical formula (2). (M ｙ ＮＰ )(M １ ｘ１ ｎ＋ ,mH ２ O)(M ２ ｘ２ M ３ ｘ３ )R ｚ (Si ｋ M ４ ｘ４ )O ｐ (OH) ｑ (2) Here, M ＮＰ are metal particles located between layers, and M １ is at least one element selected from the group consisting of alkali metal elements, Group 2 elements, and transition metal elements, and M ２ is the M １ is an element selected from the group consisting of alkali metal elements, Group 2 elements, and transition metal elements, which is different from or the same as M ３ is the M １ and the M ２ Group 2 elements, Group 3 elements and transition metal elements, which are different from or identical to M ４ is the M １ , said M ２ and the M ３ is at least one element selected from the group consisting of alkali metal elements, Group 2 elements, Group 3 elements, and transition metal elements, which is different from or the same as M ＮＰ is the M １ , said M ２ , said M ３ and the M ４ wherein R is the organic group, and n is the M 1 and m, x1, x2, x3, x4, z, k, p, and q satisfy 0≦m≦100, 0≦x1≦3, 0≦x2≦2, 2≦x3≦3, 0≦x4≦2, 1≦y≦10, 2.2≦z≦4.5, 2≦k≦5, 9≦p≦11, and 1.5≦q≦8, respectively.

8. The composite particles according to any one of claims 1 to 7, wherein the particle diameter of the composite particles is in the range of 0.5 nm to 35 µm.

9. The composite particle according to any one of claims 1 to 8, wherein the surface of the composite particle is smooth.

10. 10. The composite particle according to claim 1, wherein the organic ligand is at least one selected from the group consisting of a terpyridine group, a phenanthroline group, a bipyridine group, an imino group, and derivatives thereof.

11. The composite particle according to any one of claims 1 to 10, wherein the metal ion is at least one selected from the group consisting of Pt, Cu, Ni, Pd, Ag, Mo, Fe, Co, Ru, Rh, Eu, Zn, Os, Cr, and Mn.

12. The composite particle according to any one of claims 1 to 11, wherein the metallo-supramolecular polymer is at least one type represented by a general formula selected from the group consisting of general formulas (I), (II) and (III): 【Chemical 1】 In the formula (I), M represents a metal ion, X represents a counter anion, S represents a spacer containing a carbon atom and a hydrogen atom or a spacer directly connecting two terpyridine groups, and R １ ~R ４ each independently represents a hydrogen atom or a substituent, and n is an integer of 2 or more that represents the degree of polymerization; In the formula (II), M １ ~M Ｎ (N is an integer of 2 or more) each independently represent a metal ion having a different oxidation-reduction potential, and X １ ~X ｎ (n is an integer of 2 or more) each independently represents a counter anion, S １ ~S Ｎ (N is an integer of 2 or more) each independently represents a spacer containing a carbon atom and a hydrogen atom or a spacer directly connecting two terpyridine groups, R １ １ ~R １ Ｎ , R ２ １ ~R ２ Ｎ , R ３ １ ~R ３ Ｎ , R ４ １ ~R ４ Ｎ (N is an integer of 2 or more) each independently represents a hydrogen atom or a substituent, and n １ ~n Ｎ are each independently an integer of 2 or more indicating the degree of polymerization, In the formula (III), M represents a metal ion, X represents a counter anion, A represents a spacer containing a carbon atom and a hydrogen atom or a spacer directly connecting two phenanthroline groups, and R １ ~R ４ each independently represents a hydrogen atom or a substituent, and n is an integer of 2 or more that represents the degree of polymerization.

13. A method for producing composite particles according to any one of claims 1 to 12, comprising: preparing a particle dispersion by dispersing particles of a layered inorganic-organic covalently bonded material in which a layered silicate compound and an organic group are covalently bonded in at least one dispersion medium selected from the group consisting of methanol, ethanol, and water; preparing a polymer solution containing a metallo-supramolecular polymer; mixing and stirring the particle dispersion and the polymer solution; Removing the solvent; It encompasses The organic group is represented by X1-L1, X1 is a functional group selected from the group consisting of a heterocyclic group, an amine group, an amide group, a thioether group, a sulfone group, a nitro group, a carboxyl group, a linear or branched alkyl group, a linear or branched alkylamine group (including primary, secondary, and tertiary groups), a linear or branched quaternary alkylammonium group, a quaternary arylammonium group, coumarin, and derivatives thereof; L1 is a divalent group, The method, wherein the metallo-supramolecular polymer comprises, as repeating units, an organic ligand and a metal ion coordinated to the organic ligand.

14. 14. The method of claim 13, wherein the mixing and stirring comprises mixing the particle dispersion and the polymer solution such that the mass ratio of the metallo-supramolecular polymer to the particles is in the range of 0.1 to 40.

15. The method according to claim 13 or 14, wherein the concentration of the particles in the particle dispersion is in the range of 0.05 mg / mL to 10 mg / mL.

16. The method according to any one of claims 13 to 15, wherein the concentration of the metallo-supramolecular polymer in the polymer solution is in the range of 2 mg / mL or more and 4 mg / mL or more.

17. The method according to any one of claims 13 to 16, further comprising coating the mixture obtained by mixing and stirring prior to removing the solvent.

18. a first electrode; an electrochromic layer located on the first electrode and containing composite particles according to any one of claims 1 to 12; an electrolyte layer overlying the electrochromic layer; a second electrode positioned on the electrolyte layer; and An electrochromic device comprising:

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