阅读说明：本技术 聚合物、组合物、电致变色元件、调光装置和显示装置 (Polymer, composition, electrochromic element, light control device, and display device ) 是由 樋口昌芳 马纳斯·库马尔·贝拉 于 2019-08-15 设计创作，主要内容包括：本发明解决了提供具有电致变色特性并且能够形成在应用于电致变色元件并且脱色时看上去更透明的片材的聚合物的第一问题。解决该问题的本发明是通过以下方式得到的聚合物：在式1：BP_1-L_1-BP_2表示的化合物A与选自由配位数为4的第一金属离子、配位数为6的第二金属离子以及配位数为4和6的第三金属离子组成的组中的至少一种特定金属离子之间形成配合物,并且将配合物键合到一起。在该式中,L_1表示单键或二价基团,BP_1和BP_2可以彼此相同或不同,并且各自独立地表示联吡啶衍生物。(The present invention solves a first problem of providing a polymer having electrochromic properties and capable of forming a sheet that looks more transparent when applied to an electrochromic element and discolored. The present invention for solving the problem is a polymer obtained by: in formula 1: BP (Back propagation) of 1 ‑L 1 ‑BP 2 The compound a represented forms a complex with at least one specific metal ion selected from the group consisting of a first metal ion having a coordination number of 4, a second metal ion having a coordination number of 6, and a third metal ion having coordination numbers of 4 and 6, and bonds the complexes together. In the formula, L 1 Represents a single bond or a divalent group, BP 1 And BP 2 May be the same as or different from each other, and each independently represents a bipyridine derivative.)

1. A polymer, wherein the polymer is composed of a complex in which a compound a represented by the following formula 1 is bonded to at least one specific metal ion selected from the group consisting of a first metal ion having a coordination number of 4, a second metal ion having a coordination number of 6, and third metal ions having coordination numbers of 4 and 6:

BP₁-L₁-BP₂ (1)

wherein L is₁Represents a single bond or a divalent group, and BP₁And BP₂Each independently represents a bipyridyl derivative which may be the same as or different from each other.

2. The polymer of claim 1, wherein the compound a is represented by the following formula 2:

wherein, X₁₀To X₁₄One of them is N, the others are CR and X₁₅To X₁₉One of them is N, X₁₅To X₁₉The other of which is AND L₁Bonded carbon atoms, the remainder being CR, X₂₀To X₂₄One of them is N, the others are CR and X₂₅To X₂₉One of them is N, X₂₅To X₂₉The other of which is AND L₁A bonded carbon atom, the remainder being CR, R being a hydrogen atom or a monovalent group, and L₁Is a single bond or a divalent group.

3. The polymer according to claim 1 or 2, comprising at least one selected from the group consisting of a repeating unit represented by the following formula 4 and a partial structure represented by the following formula 5:

wherein M is₁Represents at least one selected from the group consisting of the first metal ion and the third metal ion, the first metal ion and the third metal ion being metal ions having a coordination number of 4, L₂Represents a single bond or a divalent group, a plurality of L₂And M₁May be the same as or different from each other, and is identical to L₂And M₁The carbon atom-bonded hydrogen atoms of (a) may each independently be substituted with a monovalent group;

wherein M is₂Represents at least one selected from the group consisting of the second metal ion and the third metal ion, which are metal ions having a coordination number of 6Seed, L₃Represents a single bond or a divalent group, represents a bonding position, and a plurality of M₂And L₃May be the same as or different from each other, and is identical to M₂And L₃The carbon atom-bonded hydrogen atoms of (a) may each independently be substituted with a monovalent group.

4. A composition, comprising: a polymer according to any one of claims 1 to 3; and a counter ion.

5. An electrochromic element, comprising:

a pair of electrodes arranged to face each other, at least one of the pair of electrodes being transparent; and

a composition layer formed from the composition of claim 4 disposed between the pair of electrodes.

6. The electrochromic element of claim 5, further comprising a solid electrolyte layer between one of the electrodes and the composition layer.

7. A light control device comprising the electrochromic element according to claim 5 or 6, wherein both electrodes of the pair of electrodes are transparent.

8. A display device comprising the electrochromic element according to claim 5 or 6.

Technical Field

The present invention relates to a polymer (complex), a composition, an electrochromic element, a light control device, and a display device.

Background

Recently, development of a light control device, a display device, and the like having an electrochromic element using a compound having an electrochromic property has been advanced. Patent document 1 describes a polymer material containing a bis (terpyridine) derivative, a metal ion, and a counter anion.

Reference list

Patent document

Patent document 1: JP-A-2007-112957

Disclosure of Invention

Technical problem

An electrochromic element in which a sheet formed of a material described in patent document 1 is disposed between a pair of transparent electrodes can easily control coloring and decoloring (also referred to as decoloring) by controlling an electric potential, and has excellent performance. On the other hand, the inventors of the present invention have found that a sheet of an electrochromic element may look cloudy when discolored, and thus there is room for improvement.

It is therefore an object of the present invention to provide a polymer (complex) having electrochromic properties and capable of forming a sheet which looks more transparent when applied to an electrochromic element and discolored.

In addition, another object of the present invention is to provide a composition containing such a polymer, an electrochromic element, a light control device, and a display device containing a composition layer formed of the composition.

Solution to the problem

Various aspects of the present invention to solve the above problems are as follows.

[1].

A polymer, wherein the polymer is composed of a complex in which a compound a represented by the following formula 1 is bonded to at least one specific metal ion selected from the group consisting of a first metal ion having a coordination number of 4, a second metal ion having a coordination number of 6, and third metal ions having coordination numbers of 4 and 6:

BP₁-L₁-BP₂ (1)

wherein L is₁Represents a single bond or a divalent group, and BP₁And BP₂Each independently represents a bipyridyl derivative which may be the same as or different from each other.

[2].

The polymer according to item [1], wherein the compound A is represented by the following formula 2:

wherein, X₁₀To X₁₄One of them is N, the others are CR and X₁₅To X₁₉One of them is N, X₁₅To X₁₉The other of which is AND L₁Bonded carbon atoms, the remainder being CR, X₂₀To X₂₄One of them is N, the others are CR and X₂₅To X₂₉One of them is N, X₂₅To X₂₉The other of which is AND L₁A bonded carbon atom, the remainder being CR, R being a hydrogen atom or a monovalent group, and L₁Is a single bond or a divalent group.

[3].

The polymer according to item [1] or [2], which comprises at least one selected from the group consisting of a repeating unit represented by the following formula 4 and a partial structure represented by the following formula 5:

wherein M is₁Represents at least one selected from the group consisting of the first metal ion and the third metal ion, the first metal ion and the third metal ion being metal ions having a coordination number of 4, L₂Represents a single bond or a divalent group, a plurality of L₂And M₁May be the same as or different from each other, and is identical to L₂And M₁The carbon atom-bonded hydrogen atoms of (a) may each independently be substituted with a monovalent group;

wherein M is₂Represents at least one selected from the group consisting of the second metal ion and the third metal ion, the second metal ion and the third metal ion being metal ions in a state of coordination number 6, L₃Represents a single bond or a divalent group, represents a bonding position, and a plurality of M₂And L₃May be the same as or different from each other, and is identical to M₂And L₃The carbon atom-bonded hydrogen atoms of (a) may each independently be substituted with a monovalent group.

[4].

A composition, comprising: the polymer according to any one of items [1] to [3] above; and a counter ion.

[5].

An electrochromic element, comprising:

a pair of electrodes arranged to face each other, at least one of the pair of electrodes being transparent; and

a composition layer formed of the composition according to item [4] above, disposed between the pair of electrodes.

[6].

The electrochromic element according to item [5] above, further comprising a solid electrolyte layer between one of the electrodes and the composition layer.

[7].

A light control device comprising the electrochromic element according to item [5] or [6] above, wherein both of the pair of electrodes are transparent.

[8].

A display device comprising the electrochromic element according to the above item [5] or [6 ].

Advantageous effects of the invention

According to the present invention, a polymer (complex) having electrochromic properties and capable of forming a sheet that looks more transparent when applied to an electrochromic element and discolored can be provided.

In addition, according to the present invention, a composition containing such a polymer, an electrochromic element containing a composition layer formed of the composition, a light control device, and a display device can also be provided.

Drawings

Fig. 1 is a conceptual diagram of an electrochromic element according to an embodiment of the present invention.

FIG. 2 is an infrared absorption spectrum of composition 1 containing Polymer 1 and a counterion.

FIG. 3 shows a polymer containing 1 (BP-1-Fe)²⁺) The sheet of (2) was subjected to elemental analysis by energy dispersive X-ray analysis.

FIG. 4 shows a polymer containing 1 (BP-1-Fe)²⁺) The sheet of (2) was subjected to elemental analysis by energy dispersive X-ray analysis.

FIG. 5 is an infrared absorption spectrum of composition 2 containing Polymer 2 and a counterion.

FIG. 6 shows a polymer containing 2 (BP-2-Fe)²⁺) The sheet of (2) was subjected to elemental analysis by energy dispersive X-ray analysis.

FIG. 7 shows a polymer containing 2 (BP-2-Fe)²⁺) The sheet of (2) was subjected to elemental analysis by energy dispersive X-ray analysis.

Figure 8 shows the electrochemical responses obtained by cyclic voltammetry measurements for composition 1 and composition 2.

Fig. 9 shows a photograph showing a change in color development of composition 1 (sheet) placed on an ITO electrode.

Fig. 10 shows a photograph showing a change in color development of composition 2 (sheet) placed on an ITO electrode.

Fig. 11 is the uv-vis absorption spectra of composition 1 and composition 2.

Fig. 12 shows the transmittance of composition 1 to uv-visible light.

Fig. 13 shows the transmittance of composition 2 to uv-visible light.

Fig. 14 shows the peak intensity conversion characteristics of composition 1.

Fig. 15 shows the peak intensity conversion performance of composition 2.

Fig. 16 shows the transmitted light intensity of composition 1 when the peak intensity conversion was repeated 300 times.

Fig. 17 shows the transmitted light intensity of composition 2 when the peak intensity conversion was repeated 300 times.

Fig. 18 is a scanning electron microscope image of composition 1.

Fig. 19 is a transmission electron microscope image of composition 1.

Fig. 20 is a scanning electron microscope image of composition 2.

Fig. 21 is a transmission electron microscope image of composition 2.

Fig. 22 shows the powder X-ray diffraction patterns of composition 1 and composition 2.

Description of the embodiments

Hereinafter, the present invention will be described in detail.

The following description of the elements of the present invention may be made on the basis of exemplary embodiments of the present invention, however, the present invention is not limited to such embodiments.

In the present specification, a numerical range represented by "to" means a range including numerical values before and after "to" as a lower limit and an upper limit.

In the present specification, with respect to the expression of a group (atomic group), the expression of a group which is not described as substituted or unsubstituted includes both a group having no substituent and a group having a substituent, within a range where the effect of the present invention is not impaired. For example, the expression "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group). This explanation applies equally to each compound mentioned in the following description.

[ Polymer ]

The polymer according to an embodiment of the present invention is a polymer obtained by: a compound represented by formula 1 (hereinafter also referred to as "compound a") described later and at least one specific metal ion selected from the group consisting of a first metal ion having a coordination number of 4, a second metal ion having a coordination number of 6, and third metal ions having coordination numbers of 4 and 6 are bonded to each other to form a complex.

The mechanism by which the above-mentioned polymer exerts the effect of the present invention is not always clear, but the inventors of the present invention presume as follows. Note that the following mechanism is speculative, and even a case in which the effect of the present invention is obtained by a mechanism different from the following mechanism should be included in the scope of the present invention.

The inventors of the present invention examined in depth: in an electrochromic element in which a sheet formed of the material described in patent document 1 is arranged between a pair of electrodes (typically between transparent electrodes), the sheet looks cloudy at the time of decoloring.

As a result, they found that irregular and fine pores may be generated inside the formed sheet, and the pores scatter incident light from the outside, and the sheet looks cloudy.

The inventors of the present invention have intensively studied to synthesize a polymer (organic/inorganic hybrid type polymer) by sequentially bonding a plurality of organic ligands via metal ions (by coordination bonding), form a sheet containing the above polymer, observe the structure, electrochromic properties, and the like of the polymer, to further suppress the generation of fine pores inside the sheet.

As a result, they found that in the case of using a sheet obtained by coordinating compound a as a bis (bipyridine) derivative with a specific metal ion, irregular pores are less likely to be generated inside the sheet, and an electrochromic material to which the resulting sheet is applied looks more transparent even when discolored, and they completed the present invention.

As will be described later, the polymer according to the present invention is formed such that compound a, which is a bis (bipyridine) derivative, coordinates with a specific metal ion and they are bonded together. It is presumed that the compound a has a planar structure when coordinated with a specific metal ion. For this reason, there are fewer irregular voids inside the polymer-containing sheet. As a result, when the sheet is applied to an electrochromic element, it looks more transparent (easily transmits external light and is less likely to scatter) when discolored.

It is presumed that the fact that the polymer tends to have a planar structure is supported from the viewpoint that the sheet containing the polymer according to one embodiment of the present invention has a nanosheet structure shown in fig. 18 or fig. 20, which will be described later.

Hereinafter, the polymer according to the present invention will be described in detail.

[ Compound A ]

The above-mentioned polymer is a polymer in which the compound A is bonded with a specific metal ion to form a complex. Thus, compound a may also be referred to as a ligand and also has the function as a monomer in relation to the polymer.

BP₁-L₁-BP₂ (1)

In the formula, L₁Represents a single bond or a divalent group, and BP₁And BP₂Each independently represents a bipyridyl derivative which may be the same as or different from each other.

BP₁And BP₂The bipyridine derivative of (a) is not particularly limited, and may each independently be 2, 2 '-bipyridine, 3' -bipyridine, 4 '-bipyridine, 2, 3' -bipyridine, 2, 4 '-bipyridine, 3, 4' -bipyridine, and a monovalent group (the one-one group) in which at least one of hydrogen atoms bonded to carbon atoms of these derivatives is substituted with a monovalent groupThe valency group does not include pyridyl). From the viewpoint that the polymer has more excellent effects of the present invention, 2, 2 '-bipyridine or a compound in which at least one of hydrogen atoms bonded to carbon atoms of 2, 2' -bipyridine is substituted with a monovalent group (the monovalent group does not include a pyridyl group) is preferable. The monovalent group is not particularly limited, and the substituent W described later is preferable.

In the above formula 1, L₁The divalent group of (b) is not particularly limited, and a divalent unsaturated hydrocarbon group is preferable from the viewpoint that the response speed of electrochromic is accelerated because of a broader conjugated system of pi electrons.

L₁The form of the divalent unsaturated hydrocarbon group of (2) is not particularly limited. For example, divalent groups derived from: alkenylene, alkynylene, arylene, heteroarylene, and a fused aromatic heterocyclic ring in which three or more rings are fused, and a group obtained by combining these groups.

Examples of alkenylene include vinylene, propenylene, butenylene, pentenylene, 1-methylvinylene, 1-methylpropenylene, 2-methylpropenylene, 1-methylpentene, and 3-methylpentene, 1-ethylvinylene, 1-ethylpropenylene, 1-ethylbutenylene, 3-ethylbutenylene, and the like. Among these groups, vinylidene is preferable.

Examples of alkynylene groups include ethynylene, 1-propynyl, 1-butynyl, 1-pentynyl, 1-hexynyl, 2-butynyl, 2-pentynyl, 1-methylacetylene, 3-methyl-1-propynyl, 3-methyl-1-butynyl, and the like. Among these groups, an ethynylene group is preferable.

Examples of arylene groups include ortho-phenylene, meta-phenylene, para-phenylene, naphthalenediyl, anthracenediyl, tetracenediyl, pyrenediyl, naphthylnaphthalenediyl, biphenyldiyl (e.g., [1, 1 ' -biphenyl ] -4, 4 ' -diyl, 3 ' -biphenyldiyl, 3, 6-biphenyldiyl, etc.), terphenyldiyl, tetrabiphenyldiyl, pentabiphenyldiyl, hexabiphenyldiyl, heptabiphenyldiyl, octabiphenyldiyl, nonabiphenyldiyl, decabiphenyldiyl, and the like. Among these groups, o-phenylene or p-phenylene is preferable.

Examples of the heteroarylene group include groups containing at least one atom selected from the group consisting of O and S as a hetero atom. Specific examples thereof include divalent groups derived from a thiophene ring, a dibenzofuran ring, a dibenzothiophene ring, and the like.

The divalent group derived from a fused aromatic heterocyclic ring in which three or more rings are fused is preferably a fused aromatic heterocyclic ring containing at least one hetero atom selected from the group consisting of O and S as an element constituting the fused ring. Specific examples thereof include divalent groups derived from: dibenzofuran ring, dibenzothiophene ring, naphthofuran ring, naphthothiophene ring, benzodifuran ring, benzodithiophene ring, naphthodifuran ring, naphthodithiofuran ring, anthrafuran ring, anthradifuran ring, anthradithiothiophene ring, thiaanthracene ring, thiophene ringThia-ring (phenoxathiin ring), naphtho [2, 3-b ]]Thiophene rings (naphthothiophene rings), and the like.

More specifically, the divalent unsaturated hydrocarbon group is preferably, for example, at least one group selected from the group consisting of: vinylene, ethynylene, o-phenylene, p-phenylene, thienyl (a divalent group derived from a thiophene ring), and a group obtained by combining these groups.

In addition, L₁Examples of other forms of the divalent group of (a) include chalcogen atoms, heterohydrocarbon groups containing chalcogen atoms, and the like. Specific examples thereof include O, S, alkyleneoxy groups, alkylenethio groups, and groups obtained by combining these groups.

In addition, L₁The divalent group of (b) may be a divalent group represented by the following formula. In the following formulae, "+" indicates a bonding site. In addition, in the following divalent groups, a hydrogen atom bonded to each carbon atom may be substituted with a monovalent group, and examples of the monovalent group include the substitutions described laterA radical W.

As the compound a, a compound represented by the following formula 2 is preferable.

In the formula, X₁₀To X₁₄One of them is N, the others are CR and X₁₅To X₁₉One of them is N, X₁₅To X₁₉The other of which is AND L₁Bonded carbon atoms, the remainder being CR, X₂₀To X₂₄One of them is N, the others are CR and X₂₅To X₂₉One of them is N, X₂₅To X₂₉The other of which is AND L₁A bonded carbon atom, the remainder being CR, R being a hydrogen atom or a monovalent group, and L₁Is a single bond or a divalent group.

In particular, from the viewpoint that a polymer having more excellent effects of the present invention can be obtained, as the compound a, a compound represented by the following formula 3 is more preferable.

In the formula, L₁Represents a single bond or a divalent group, and has a structure represented by L in formula 1₁Forms similar to those already described. In addition, in the above formula, the hydrogen atom bonded to each carbon atom may be substituted with a monovalent group (excluding a pyridyl group), and the monovalent group is not particularly limited, and the substituent W described later is preferable.

[ specific Metal ion ]

The polymer according to the present invention is a polymer formed in such a manner that the compound a forms a complex with a specific metal ion, in other words, the compounds a are continuously bonded to each other via the specific metal ion.

The specific metal ion is at least one selected from the group consisting of: a first metal ion having a coordination number of 4 (which means a metal ion in a state having a coordination number of 4), a second metal ion having a coordination number of 6 (which means a metal ion in a state having a coordination number of 6), and third metal ions having coordination numbers of 4 and 6 (which means metal ions capable of being in a state having a coordination number of 4 and a state having a coordination number of 6 at the same time).

As the specific metal ion, one kind may be used, or two or more kinds thereof may be used in combination.

(first Metal ion)

The first metal ion is not particularly limited, and examples thereof include Pd, Au, Zn, and the like. More specific examples thereof include ions such as pd (ii), au (iii), zn (ii), and the like. From the viewpoint of more easily exhibiting electrochromic properties, metal ions that can be electrochemically oxidized and reduced are preferable. More specifically, Zn (II), etc. are preferable.

(second Metal ion)

The second metal ion is not particularly limited, and examples thereof include Mg, Al, Cr, Mn, Fe, and the like. More specific examples thereof include ions such as mg (ii), al (iii), cr (iii), mn (ii), mn (iii), fe (ii), and fe (iii), os (ii), and os (iii). From the viewpoint of more easily exhibiting electrochromic properties, metal ions that can be electrochemically oxidized and reduced are preferable. More specifically, Fe (II), Fe (III), Os (II), Os (III), etc. are preferable.

(third Metal ion)

The third metal ion means a metal ion which can adopt a state with a coordination number of 4 or a state with a coordination number of 6. Such metal ions are not particularly limited, and examples thereof include Cu, Co, and Pt. More specific examples thereof include Cu (I), Cu (II), Co (III), Pt (II), Pt (IV), etc. Among them, metal ions that can be electrochemically oxidized and reduced are preferable from the viewpoint of more easily exhibiting electrochromic properties. More specifically, Cu (I), Cu (II), Co (III), etc. are preferable.

[ Structure of Polymer ]

The polymer according to the invention is formed in the following manner: such that the two bipyridyl derived moieties (BP) of Compound A₁And BP₂) One of them and the other bipyridyl-derived moiety of the compound a form a complex with the specific metal ion, and as a result, the bipyridyl-derived moiety is continuously bonded via the specific metal ion.

At this time, when the polymer contains the second metal ion and/or the third metal ion (in a state of coordination number of 6), the three compounds a are coordinately bound around the metal ion. As a result, a branched structure is formed.

On the other hand, when the polymer contains the first metal ion and/or the third metal ion (in a state of coordination number of 4) as the specific metal ion, two compounds a are coordinately bound around the metal ion. As a result, a linear structure is formed. In addition, a cyclic structure may be formed by combining a linear structure and a branched structure.

The structure of the polymers according to the invention may be linear, branched or cyclic. From the viewpoint that the obtained sheet has more excellent resistance to organic solvents, it is preferable that the obtained sheet contains the second metal ion and/or the third metal ion (in a state of coordination number of 6), that is, has at least a branched structure.

(preferred form of Polymer)

From the viewpoint that a polymer having more excellent effects of the present invention can be obtained, the polymer preferably has at least one selected from the group consisting of: a repeating unit represented by the following formula 4 (hereinafter also referred to as "unit 4") and a partial structure represented by the following formula 5 (hereinafter also referred to as "partial structure 5").

In the formula, M₁Represents a metal ion selected from the group consisting of a first metal ion and a third metal ion (in a state of coordination number 4)At least one of the group L₂Represents a single bond or a divalent group, some L₂And M₁May be the same as or different from each other, and the hydrogen atoms bonded to each carbon atom may each independently be substituted with a monovalent group.

Note that L₂The divalent group of (A) is not particularly limited and has been represented by L in formula 1₁The groups described are preferred. In addition, M₁The forms of the first metal ion and the third metal ion (in a state of coordination number of 4) of (a) are not particularly limited and are as described above.

From the viewpoint that a polymer having more excellent effects of the present invention can be obtained, M is preferable₁Is a metal ion of at least one metal selected from the group consisting of Pd, Au, Zn, Cu, Co and Pt (in a state of coordination number 4).

In addition, the monovalent group is not particularly limited, and the substituent W described later is preferable.

Note that the repeating unit is formed by coordinating compound a with the first metal ion and/or the third metal ion (in a state of coordination number of 4).

In the formula, M₂Represents a second metal ion and/or a third metal ion (in a state of coordination number of 6), L₃Represents a single bond or a divalent group, represents a bonding site, and has a plurality of M₂And L₃May be the same as or different from each other, and the hydrogen atoms bonded to each carbon atom may each independently be substituted with a monovalent group.

L₃The divalent group of (A) is not particularly limited, and is L in the formula 1₁The groups already described are preferred. In addition, M₂The forms of the second metal ion and the third metal ion (in a state of coordination number of 6) of (a) are not particularly limited and are as described above.

In particular, the more excellent effects of the present invention can be obtainedFrom the viewpoint of the fruit polymer, M is preferred₂The metal ion of (b) is a metal ion of at least one metal selected from the group consisting of Mg, Al, Cr, Mn, Fe, Cu, Co, Os and Pt (in a state of coordination number of 6).

In addition, the monovalent group is not particularly limited, and the substituent W described later is preferable.

Note that a partial structure is formed by coordinating compound a with a second metal ion and/or a third metal ion (in a state of coordination number 6).

The polymer according to an embodiment of the present invention has at least one selected from the group consisting of the above-described unit 4 and partial structure 5. Hereinafter, the repeating unit and the partial structure are collectively referred to as "specific structure".

The structure of the polymer according to the above embodiment is not particularly limited as long as it has a specific structure, and may contain only the unit 4 or may contain only a part of the structure 5. When the polymer contains the unit 4 and the partial structure 5, the bonding order of the unit 4 and the partial structure 5 is not particularly limited. For example, as represented by the following formula 6, the end portions of the linear oligomer formed by the unit 4 are bonded to the partial structures 5, respectively, and as a result, a branched structure can be formed. In addition, the polymer molecule may contain a plurality of the following structures.

In the formula, M₁And L₂Are respectively similar to M in formula 4₁And L₂And M is₂And L₃Are respectively similar to M in formula 5₂And L₃。

In addition, n1, n2, and n3 each represent an integer of 1 or more.

In addition, the polymer may have a multiple-branched structure formed by connecting the partial structures 5 to each other. Examples of the multiple branched structure include a structure represented by the following formula 7.

In the formula, M₂And L₃Are respectively similar to M in formula 5₂And L₃. In addition, denotes a bonding site.

The polymers represented by the above-mentioned formulas 6 and 7 are examples, and the polymer according to the present invention is not limited thereto.

The above polymers are typically insoluble in a common solvent, and it is difficult to measure the molecular weight of the polymer by a general molecular weight measurement method such as Gel Permeation Chromatography (GPC). The shape of the polymer can be confirmed with a scanning electron microscope and/or a transmission electron microscope. Typically, the polymer is prepared in the form of a sheet structure having a diameter of several tens of nanometers to several centimeters and a thickness of about 0.3 nanometers to several μm.

(substituent W)

The substituent W is a monovalent group free of pyridyl. Specific examples thereof include: halogen atom, alkyl group (e.g., methyl group, ethyl group, propyl group, isopropyl group, t-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (e.g., cyclopentyl group, cyclohexyl group, etc.), alkenyl group (e.g., vinyl group, allyl group, etc.), alkynyl group (e.g., ethynyl group, propargyl group, etc.), alkoxy group (e.g., methoxy group, ethoxy group, propoxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (e.g., cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (e.g., phenoxy group, naphthyloxy group, etc.), alkylthio group (e.g., methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (e.g., cyclopent, Alkoxycarbonyl (e.g., methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl, octyloxycarbonyl, dodecyloxycarbonyl, etc.), aryloxycarbonyl (e.g., phenoxycarbonyl, naphthyloxycarbonyl, etc.), sulfamoyl (e.g., aminosulfonyl, methylaminosulfonyl, dimethylaminosulfonyl, butylaminosulfonyl, hexylaminosulfonyl, cyclohexylaminosulfonyl, octylaminosulfonyl, dodecylaminosulfonyl, phenylaminosulfonyl, naphthylaminosulfonyl, etc.), and the like.

The substituent W may be an acyl group (e.g., acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, acryloyl group, methacryloyl group, phenylcarbonyl group, naphthylcarbonyl group, etc.), an acyloxy group (e.g., acetoxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), an amide group (e.g., methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), a carbamoyl group (e.g., aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, dimethylaminoc, Propylaminocarbonyl, pentylaminocarbonyl, cyclohexylaminocarbonyl, octylaminocarbonyl, 2-ethylhexylaminocarbonyl, dodecylaminocarbonyl, phenylaminocarbonyl, naphthylaminocarbonyl and the like), ureido (e.g., methylureido, ethylureido, pentylureido, cyclohexylureido, octylureido, dodecylureido, phenylureido, naphthylureido and the like), sulfinyl (e.g., methylsulfinyl, ethylsulfinyl, butylsulfinyl, cyclohexylsulfinyl, 2-ethylhexylsulfinyl, dodecylsulfinyl, phenylsulfinyl, naphthylsulfinyl and the like), alkylsulfonyl (e.g., methylsulfonyl, ethylsulfonyl, butylsulfonyl, cyclohexylsulfonyl, 2-ethylhexylsulfonyl, dodecylsulfonyl and the like), arylsulfonyl or heteroarylsulfonyl (e.g., phenylsulfonyl, naphthylsulfonyl, and the like), amino (including amino, alkylamino, alkenylamino, arylamino, heterocyclic amino, e.g., amino, ethylamino, dimethylamino, butylamino, cyclopentylamino, 2-ethylhexylamino, dodecylamino, anilino, naphthylamino, and the like), cyano, nitro, hydroxyl, mercapto, silyl (e.g., trimethylsilyl, triisopropylsilyl, triphenylsilyl, phenyldiethylsilyl, and the like), and the like.

Each of these groups may further have a substituent, and examples of the substituent include the substituents described above. Examples thereof include aralkyl groups in which an aryl group is substituted with an alkyl group, hydroxyalkyl groups in which a hydroxyl group is substituted with an alkyl group, and the like. When the substituent W further has a plurality of substituents, the plurality of substituents may be bonded to each other to form a ring.

In particular, from the viewpoint that a polymer having more excellent effects of the present invention can be obtained, the substituent W is preferably a hydrocarbon group having 1 to 10 carbon atoms, which may have a hetero atom, more preferably an alkyl group having 1 to 10 carbon atoms, and still more preferably an alkyl group having 1 to 6 carbon atoms.

[ Process for producing Polymer ]

The method for preparing the polymer according to the present invention is not particularly limited, and known methods may be applied. In particular, a method for producing a polymer comprising the following steps is preferable from the viewpoint that the polymer can be obtained more easily and more quickly.

That is, a preferred method for preparing a polymer comprises the steps of:

synthesizing a compound a (step 1);

preparing a solution containing compound a and an organic solvent, and an aqueous solution containing a compound as an ion source of a specific metal ion, and bringing the solution and the aqueous solution into contact with each other to form a water/oil interface (step 2); and

compound a is polymerized at the water/oil interface by specific metal ions (step 3).

(step 1)

Step 1 is a step of synthesizing compound a. The method for synthesizing compound a is not particularly limited, and known methods can be applied. As a method for synthesizing the compound a, for example, wittig reaction and the like can be used. More specifically, the method described in inorg. chem.1995, 34, 473-.

(step 2)

Step 2 is a step of preparing a solution containing compound a and an organic solvent (compound a solution), and an aqueous solution containing a compound as an ion source of a specific metal ion (metal ion aqueous solution), and bringing the solution and the aqueous solution into contact with each other to form a water/oil interface.

Solution of Compound A

The organic solvent contained in the compound a solution is not particularly limited as long as it is an organic solvent that can dissolve the compound a and is less likely to be miscible (preferably immiscible) with water. Examples of the organic solvent include alkyl halides such as dichloromethane.

The content of compound a in the compound a solution is not particularly limited. In general, the content is preferably 0.05mM (mmol/l) to 1.0M (mol/l) relative to the total mass of the compound A solution.

The compound a solution may contain two or more compounds a. When the compound a solution contains two or more compounds a, the total content thereof is preferably within the above range.

Aqueous solution of metal ions

The metal ion aqueous solution is an aqueous solution containing a specific metal ion, and is typically an aqueous solution in which a compound as an ion source is dissolved. Note that specific metal ions have been described.

The compound as the ion source is preferably a metal salt composed of a specific metal ion and its counter anion. At this time, the counter anion is preferably at least one selected from the group consisting of: acetate ion, phosphate ion, chloride ion, hexafluorophosphate ion, tetrafluoroborate ion (fluoroborate ion), and polyoxometalate ion.

The content of the compound (typically, metal salt) as the ion source in the aqueous solution of metal ions is not particularly limited. Generally, the content is preferably 1mM to 500mM, and more preferably 10mM to 300mM, with respect to the total mass of the aqueous solution of metal ions.

A method for contacting the compound a solution with the aqueous metal ion solution to form a water/oil interface is not particularly limited, and examples thereof include a method in which the compound a solution is held in a container at room temperature under atmospheric pressure and the aqueous metal ion solution is slowly added to the container.

(step 3)

Step 3 is a step of polymerizing compound a at the water/oil interface by metal ions. The polymerization method is not particularly limited, and examples thereof include a method in which the reaction is carried out at 10 to 30 ℃ for 2 to 24 hours under atmospheric pressure.

Generally, the polymer according to one embodiment of the present invention coordinates to a metal ion rapidly due to the structure of compound a. As a result, the polymer has the following significant advantages: the reaction is carried out under milder conditions (e.g., at room temperature and at atmospheric pressure) in a short time (e.g., within 24 hours).

Note that reference may be made to j.am.chem.soc.2015, 137, 4681-4689 as to the preparation method at the water/oil interface, and the disclosure of this document is incorporated herein.

[ composition ]

A composition according to one embodiment of the invention contains a polymer and a counterion (typically a counter anion). The form of the composition is not particularly limited as long as it contains a polymer and a counter ion, and examples thereof include a sheet and a liquid material containing a solvent described later. In compositions containing counterions, the charge of the polymer is more likely to remain neutral, resulting in higher polymer stability.

The counter ion is not particularly limited, and at least one counter ion selected from the group consisting of: acetate ions, phosphate ions, chloride ions, hexafluorophosphate ions, tetrafluoroborate ions and polyoxometallate ions.

The counterion can be a counterion that is intentionally added to the composition, or can be a counterion that is either accidentally contained in the composition or derived from the synthetic starting material of the polymer during synthesis of the polymer (typically the counter anion of a metal salt that is the source of the particular metal ion).

The content of the counter ion in the composition is not particularly limited. Typically, when the counter ion is supplied from a metal salt (ion source of a specific metal ion), the content of the metal salt in the composition is not particularly limited and may be appropriately controlled.

In addition, the composition contains a polymer. The form of the polymer is as described above. The content of the polymer in the composition is not particularly limited, and is usually 0.001 to 99.9 mass%.

In addition, the composition may contain a solvent, and examples of the solvent include water and/or an organic solvent. This makes it easier to manufacture an electrochromic element described later when the composition contains a solvent.

The above composition contains a polymer having electrochromic properties and a counter ion (generally a counter anion) that improves stability by making the polymer electrically neutral, so that the composition can be preferably used for an electrochromic element described later.

[ electrochromic element ]

The electrochromic element according to the present invention is an electrochromic element having at least a pair of electrodes arranged to face each other and a composition layer formed of the above composition arranged between the electrodes.

Fig. 1 shows a conceptual diagram of an electrochromic element according to an embodiment of the invention as a non-limiting example.

The electrochromic element 100 includes a pair of transparent electrodes (a first transparent electrode 101 and a second transparent electrode 104) arranged to face each other, a composition layer 102 arranged on the first transparent electrode 101, and a second transparent electrode 104 arranged above the composition layer 102.

Note that in the electrochromic element 100, both electrodes arranged to face each other are transparent electrodes, and external light can be transmitted, so the electrochromic element is preferably used as a light control device. When the electrochromic element is used as a display element, at least one of the electrodes may be a transparent electrode. In the display element, it is preferable that the transparent electrode side is a visual recognition side.

The electrochromic element 100 has a polymer solid electrolyte 103 between a second transparent electrode 104 and a composition layer 102 formed of the above composition. The electrochromic element according to the present invention is not limited to the above, and does not necessarily have a polymer solid electrolyte.

The first transparent electrode 101 and the second transparent electrode 104 are not particularly limited as long as they are transparent conductive films. Typically, SnO₂Film, In₂O₃Film or ITO (indium tin oxide) film which is In₂O₃And SnO₂Mixtures of (b) are preferred. The first transparent electrode 101 and the second transparent electrode 104 may be formed on a transparent substrate such as a glass substrate by any physical or chemical vapor deposition method.

The composition layer 102 is a layer formed from a composition containing the above-described polymer and a counter ion (typically a counter anion). The method for forming the composition layer 102 is not particularly limited. In general, examples thereof include a method in which the composition layer 102 is formed by coating the first transparent electrode 101 with a composition containing a solvent. Examples of the coating method include spin coating, dip coating, and the like.

In addition, in another embodiment, the composition layer 102 may be obtained by applying the sheet of the composition containing the polymer and the counter ion formed in step 3 directly onto the transparent electrode 101.

The thickness of the composition layer 102 may vary depending on the color depth of the composition used, and the like. In one embodiment, the thickness of the composition layer 102 may be approximately 0.02 microns or more and 200 microns or less, and more preferably 0.1 microns or more and 10 microns or less.

The polymer solid electrolyte 103 is formed by dissolving an electrolyte in a polymer for matrix. The electrolyte may be used in combination with a colorant to improve contrast. Note that when it is not necessary to improve the contrast, a colorant is not necessary.

When a polymer electrolyte is used, the thickness of the polymer electrolyte layer 103 is not particularly limited. It is desirable that the thickness of the polymer electrolyte layer 103 is about 10 micrometers or more in order to prevent the composition layer 102 and the second transparent electrode 104 from being in physical contact with each other due to vibration or the like.

Next, the operation of the electrochromic element 100 will be described.

The first transparent electrode 101 and the second transparent electrode 104 are connected to a power source (not shown), and a predetermined voltage is applied to the composition layer 102 and the polymer solid electrolyte 103. Thereby, the oxidation and reduction of the polymer in the composition layer 102 can be controlled.

More specifically, when a predetermined voltage is applied, the redox reaction of the metal ions of the polymer in the composition layer 102 can be controlled. As a result, the color development and discoloration of the electrochromic element can be controlled.

The electrochromic element can be applied to a light control device, a display device, and the like.

Examples

The present invention will be described in more detail based on the following examples. Materials, amounts, ratios, processes, processing procedures, and the like shown in the following examples may be appropriately changed without departing from the spirit of the present invention. The scope of the invention should therefore not be interpreted restrictively by the following examples.

All chemicals used in the following examples were purchased from Aldrich Chemical co., Tokyo Chemical Industry co., Ltd. (TCI), Wako Pure Chemical Industries, ltd., and Kanto Chemical co.

Indium Tin Oxide (ITO) -coated glass substrate (resistivity: 8 to 12. omega./sq) and anhydrous lithium perchlorate (LiClO)₄) Purchased from Aldrich Chemical co.

Anhydrous grade solvents were used for the synthesis, and spectrophotometric grade solvents were used for film preparation, spectroscopic evaluation, component preparation, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Atomic Force Microscopy (AFM) measurements.

Column chromatography was performed using silica gel 60N (neutral, 40 to 100mM) purchased from Kanto Chemical co. For experiments requiring water, purified water from the Milli-Q purification system was used.

Nuclear Magnetic Resonance (NMR) spectra were recorded at 300MHz on a JEOL AL300/BZ instrument. Chemical shifts are given relative to Tetramethylsilane (TMS).

MALDI mass spectrometry (MALDI-TOF) was measured using a time-of-flight (TOF) mass spectrometer (AXIMA-CFR, Shimadzu/Kratos) using 1, 8, 9-trihydroxyanthracene as the matrix. Compounds 3, 4, 5 and BP-1 were prepared according to the following procedures, respectively.

(Synthesis of Compound 3)

Compound 3 was synthesized from compound 1 based on the following scheme.

Will twoAn alkane (50mL) was added to Compound 1(1.8g, 9.7mmol) in a 100-mL round bottom flask and the solution was purged with nitrogen for 15 minutes. Selenium dioxide (1.1g, 9.9mmol) was then added to the flask and nitrogen purging continued for an additional 20 minutes. The solution was then heated to reflux for 24 hours and solid selenium metal was precipitated on the sides of the flask as the reaction proceeded. After that, the solution was cooled to room temperature and then gravity filtered. The solvent was removed under reduced pressure to give a solid product. The solid product was dissolved in ethyl acetate, heated to reflux for 1 hour, and gravity filtered while hot. Thereafter, the filtrate was washed with 0.1M sodium carbonate (2 × 30mL) and the bipyridylic acid formed was extracted and extracted into a 0.3M sodium metabisulfite solution. Sodium bicarbonate was added to adjust the pH of the extract to 10 and the product was extracted into Dichloromethane (DCM). The solvent was evaporated under reduced pressure to give compound 3(0.82g, 43% yield).

¹H-NMR(300MHz，CDCl₃)δ(ppm)10.19(s，1H)，8.91(d，1H)，8.84(s，1H)，8.59(d，1H)，8.28(s，1H)，7.74(d，1H)，7.21(d，1H)，2.47(s，3H)。

MALDI-TOF(m/z)：[M+H]⁺Calculated values: 198.23, measurement: 198.87.

(Synthesis of Compound 4)

Compound 4 was synthesized from compound 2 based on the following scheme.

Compound 2(0.1g, 0.38mmol) and excess PPh₃(triphenylphosphine, 1g, 3.8mmol) was added to toluene (5mL) and the resulting solution was heated at 60 ℃ for 2 h.

Then, the mixture was cooled to room temperature and filtered. Thereafter, the residue was washed with toluene and dried under vacuum overnight, thereby obtaining compound 4(0.152g, 90% yield), which was used without further purification.

¹H-NMR(300MHz，DMSO-d6)δ(ppm)8.54(d，1H)，8.41(d，1H)，8.17(s，1H)，8.10(s，1H)，7.89-7.73(m，12H)，7.25(m，1H)，7.16(m，1H)，5.39-5.33(d，2H)，2.51(s，3H)。

MALDI-TOF(m/z)：[M+H]⁺Calculated values: 445.53, measurement: 445.60.

(Synthesis of Compound 5)

Compound 5 was synthesized from compound 2 based on the following scheme.

Compound 2(3g, 11.4mmol) and triethyl phosphite (20mL) were dissolved in 100mL of CHCl₃And refluxed at 80 ℃ for 24 hours in a nitrogen atmosphere.

The solution was then cooled to room temperature, after which the solvent and excess triethyl phosphite were removed under reduced pressure. Thus, an oily brown residue was obtained and the residue was purified by column chromatography (silica gel, acetone as eluent). Finally, a clear oily liquid was obtained (3, 1g, 85% yield).

¹H-NMR(300MHz，CDCl₃)δ(ppm)8.62(1H，d)，8.54(1H，d)，8.32(1H，s)，8.23(1H，s)，7.32(1H，d)，7.13(1H，d)，4.10(4H，m)，3.28(2H，d)，2.44(3H，s)，1.27-1.39(6H，m)。

MALDI-TOF(m/z)：[M+H]⁺Calculated values: 320.33, measurement: 320.97.

(Synthesis of BP-1)

BP-1 was synthesized from compound 3 and compound 4 based on the following scheme.

Compound 3(0.220g, 1.12mmol) and compound 4(0.670g, 1.28mmol) were dissolved in ethanol (EtOH; 30mL) and stirred at 0 ℃ under nitrogen for 20 minutes. A solution of 0.3M NaOEt/EtOH (4mL) was then added dropwise over 5 minutes to warm the solution to room temperature. Then, after 5 hours, the volume was reduced to 15mL by evaporation under reduced pressure, and H was added₂O(10mL)。

The mixture was filtered to isolate the product as a white powder, and the powder was washed with 1: 1H₂Washed with O/EtOH, dried in vacuo, and finally recrystallized from methanol (MeOH). 0.175g (yield 43%) of BP-1 was obtained.

¹H-NMR(300MHz，CDCl₃)δ(ppm)8.70(2H，d)，8.60-8.58(4H，m)，8.27(2H，s)，7.42(2H，s)，7.40-7.17(2H，d)，2.43(6H，s)。

MALDI-TOF(m/z)：[M+H]⁺Calculated values: 364.45, measurement: 364.82.

IR：1590cm^-1(C＝C)。UV：288nm(1×10^-5M，DCM)。

(Synthesis of BP-2)

BP-2 was synthesized from compound 5 and compound 6 based on the following scheme.

Solid potassium tert-butoxide (0.45g, 4mmol) was added in one portion to compound 5(0.704mg, 2.2mmol) and compound 6: terephthalaldehyde (0.134g, 1mmol) in 50mL Tetrahydrofuran (THF).

Then, the reaction mixture was stirred at room temperature for 10 hours. After this time, the reaction mixture was quenched with water (25mL), THF was removed under reduced pressure, and the aqueous residue was extracted with DCM.

The collected organic layers were washed with water (50mL), dried over magnesium sulfate, and filtered. After evaporation of the solvent, the residue was recrystallized from a DCM/hexane (1: 2) solvent mixture and a yellow crystalline solid product was obtained (0.30g, 65% yield).

¹H-NMR(300MHz，CDCl₃)δ(ppm)8.67(2H，d)，8.60-8.54(4H，m)，8.28(2H，d)，7.60(4H，m)，7.50-7.41)，7.20-7.15(4H，m)，2.47(6H，sb)。

MALDI-TOF(m/z)：[M+H]⁺Calculated values: 466.59, measurement: 466.57.

IR：1588cm^-1(C＝C)。UV：358nm(1×10^-5M，DCM)。

(preparation of composition 1)

By dissolving 1mg of BP-1 in 10mL of CH₂Cl₂To prepare BP-1 in CH₂Cl₂And the solution was filtered before use.

The solution was poured into a vial having a diameter of 40mm, and pure water (10mL) was poured into the solution of BP-1 to form a water/oil interface.

Then Fe (BF) by slow pipetting₄)₂Was added to the aqueous phase (50mM, 10mL, filtered before use). After 24 hours, polymer 1 of the violet film was synthesized at the interface.

The aqueous layer was then replaced with pure water, after which both the organic and aqueous phases were removed. Mixing ethanol and CH₂Cl₂Added to the membrane to obtain a suspension of flakes comprising the membrane. The membrane was then collected by filtration and vacuum dried to give a sheet of composition 1.

Note that composition 1 contained "BP-1-Fe²⁺"(Polymer 1) (which is prepared by reacting BP-1 with Fe²⁺Coordinate and polymerize itThe polymer obtained by the combination) and a counter anion (fluoroborate).

The infrared absorption (IR) spectrum of the above composition was measured. The measurement method will be described later. The results are shown in fig. 2. In FIG. 2, "BP-1-Fe²⁺"denotes composition 1 containing Polymer 1.

As can be seen from fig. 2, the peak corresponding to C ═ C bond was 1590cm in BP-1 (compound a)^-1But moved to 1612cm in composition 1^-1。

Note that composition 1 is at 1150cm^-1The absorption in the vicinity corresponds to the counter anion (fluoroborate ion) contained in the above sheet.

In addition, fig. 3 and 4 show the results of elemental analysis of the sheet containing the polymer 1 by energy dispersive X-ray analysis. From the above, it was confirmed that the sheet contained carbon, iron, boron, nitrogen and fluorine, and "BP-1-Fe²⁺"(Polymer 1) and a counter anion.

(Synthesis of composition 2)

Except using BP-2 in CH₂Cl₂Composition 2 was prepared in a similar manner to composition 1 except that the 0.12mM solution in (1) was used instead of the BP-1 solution. The resulting sheet was magenta in color.

Composition 2 contains "BP-2-Fe²⁺"(Polymer 2) (which is prepared by reacting BP-2 with Fe²⁺A polymer obtained by coordinating and polymerizing) and a counter anion (fluoroborate ion). Note that, similarly to composition 1, the infrared absorption spectrum of composition 2 is shown in fig. 5, and the elemental analysis results obtained by energy dispersive X-ray analysis are shown in fig. 6 and 7.

First, the electrochemical responses of composition 1 and composition 2 were investigated by cyclic voltammetry measurement described later. The results are shown in fig. 8. In FIG. 8, "BP-1-Fe²⁺"corresponds to composition 1 containing Polymer 1, and" BP-2-Fe²⁺"corresponds to composition 2 containing polymer 2.

In FIG. 8, the peak observed at sweep from 20.3V to +1.0V shows oxidation, while the peak observed at sweep from +1.0V to 0.3V shows reduction. The oxidation is due to the change of iron ions from divalent to trivalent in the polymer, and the reduction is due to the change of iron ions from trivalent to divalent.

Since the peak current values indicating oxidation and reduction were the same, it was found that oxidation and reduction reversibly proceeded. Note that even if such scanning was repeated 500 times, the results did not change, and each composition containing a polymer did not exhibit fatigue due to the application of voltage.

Next, the color development change of each composition was visually observed. Each composition (sheet) placed on a transparent electrode (ITO electrode) was used as a sample, and a change in color development upon application of voltage was observed. The results for composition 1 are shown in fig. 9, and the results for composition 2 are shown in fig. 10.

As shown in FIG. 9, composition 1 is derived from "BP-1-Fe²⁺", and in the reduced state is purple-clear (fig. 9, left). Then, when a voltage is applied, the purple color disappears, and the composition becomes colorless and transparent (fig. 9, right side, decolored state). Composition 1 is derived from "BP-1-Fe²⁺", and is considered to be less scattering of incident light from the outside in the decolored state. As a result, it was found that the composition appeared more transparent and had excellent properties.

In addition, as shown in FIG. 10, composition 2 is derived from "BP-2-Fe²⁺", and magenta-transparent in the reduced state (fig. 10, left side). Then, when a voltage was applied, magenta disappeared and the composition became pale yellow transparent (fig. 10, right side, decolored state). Composition 2 is derived from "BP-2-Fe²⁺", and is considered to be less scattering of incident light from the outside in the decolored state. As a result, it was found that the composition appeared more transparent and had excellent properties.

Fig. 11 is a graph showing the ultraviolet-visible absorption spectrum of each composition measured by the method described later.

According to FIG. 11, composition 1 (denoted "BP-1-Fe" in FIG. 11)²⁺") has a peak near 400nm and a larger peak near 570 nm. This corresponds to the following fact: "BP-1-Fe²⁺AtIn the reduced state, it was purple (transparent).

In addition, according to FIG. 11, composition 2 (indicated as "BP-2-Fe" in FIG. 11)²⁺") has a large peak around 591 nm. This corresponds to the following fact: "BP-2-Fe²⁺"exhibits magenta (clear) in the reduced state.

Furthermore, according to FIG. 11, regarding "BP-1-Fe²⁺"and" BP-2-Fe²⁺"1: 1 mixture (in FIG. 11," BP-1-Fe²⁺：BP-2-Fe²⁺1: 1 ") to give a spectrum reflecting the properties of each of the polymers described above. From these results, it was found that the color development of an electrochromic element can be controlled by using the polymer according to an embodiment of the present invention.

In addition, FIGS. 12 and 13 show the transmittance for ultraviolet visible light (FIG. 12: composition 1, FIG. 13: composition 2) measured in a similar manner as described above. In these figures, it was confirmed that the spectrum of transmitted light was reversibly changed (color development and discoloration occurred) by applying a voltage. The transmittance at that time was also calculated.

The conversion performance of each peak intensity is shown in fig. 14 and 15. FIG. 14 shows the voltage applied from 1.0V (vs. Ag/Ag)⁺) Becomes 0.4V (relative to Ag/Ag)⁺) Change in the intensity of transmitted light at 588.4nm of composition 1.

In addition, FIG. 15 shows that the voltage applied to composition 2 was from 1.0V (vs. Ag/Ag)⁺) Becomes 0.4V (relative to Ag/Ag)⁺) The change in the intensity of transmitted light at a wavelength of 568.2 nm. From the above, it was found that a state change from a colored state to a decolored state rapidly occurred in each polymer.

The transmitted light intensity of composition 1 and the transmitted light intensity of composition 2 when the peak intensity conversion was repeated a plurality of times (300 times) are shown in fig. 16 and 17, respectively.

From these results, it was found that, when the color development and the decoloring were repeated, there was no change in the transmitted light intensity and the response speed of all the compositions, but they had excellent durability (excellent fatigue resistance).

The results obtained from the above experiments are summarized in table 1.

[ Table 1]

Note that in Table 1, "Δ T" has been explained, and "T" is_Colouring"response speed for color development," t_Decoloring"is a response speed of decoloring," charge/discharge "is injection/discharge of electric charge, and η represents coloring efficiency.

The coloring efficiency represents Δ OD (optical density change) with respect to the amount of charge injected into a unit area, and can be calculated from the area of the film and the above measurement value.

In Table 1, "BP-1-Fe²⁺"corresponds to composition 1, and" BP-2-Fe²⁺"corresponds to composition 2.

Fig. 18 and 19 show scanning electron microscope and transmission electron microscope images of composition 1 obtained by the following methods.

In addition, fig. 20 and 21 show scanning electron microscope and transmission electron microscope images of composition 2 obtained by the following methods.

From the above results, it was found that each of the compositions 1 and 2 had a structure in which a plurality of sheet structures were stacked (nanosheet structure). This is presumed to be due to the fact that: the polymer according to one embodiment of the present invention is a polymer formed by coordinating a predetermined compound a with a specific metal ion, and thus is more easily two-dimensionally arranged.

The composition containing the polymer having such a structure according to an embodiment of the present invention exhibits excellent resistance to organic solvents.

[ comparative example ]

In a 100ml two-necked flask, 1, 4-bis (terpyridine) benzene (30mg, 0.054mol) as a ligand was dissolved in 25ml of acetic acid while heating. Next, 5ml of a methanol solution containing iron acetate (9.39mg, 0.054mol) was added to the two-necked flask, and a mixture was obtained. The mixture was heated to reflux at 150 ℃ for 24 hours under a nitrogen atmosphere.

After refluxing, the reaction solution in the two-necked flask was transferred to a petri dish and dried in air to obtain polymer C, which was a purple powder polymer. The yield of the powder was 90%.

A film was formed on the ITO electrode using polymer C, and the state was changed to a decolored state. The formed film appeared white and turbid, and the effect required in the present application was found not to be obtained.

Specifically, each of the above evaluations was performed by the following method.

(ultraviolet visible Spectroscopy measurement)

The absorption spectra were recorded using a Shimadzu UV-2550 UV-vis spectrophotometer.

DCM solution (5X 10) was used for the ligands BP-1 and BP-2^-6M), and composition 1 having a nanosheet shape and composition 2 having a nanosheet shape were measured on an ITO substrate.

(scanning Electron microscope (SEM) and Transmission Electron Microscope (TEM) Observation)

Nanosheets of polymer 1 and polymer 2 were Sputter coated using a platinum coater (E-1030Ion sprayer, Hitachi, ltd., Tokyo, Japan) and then observed with a Scanning Electron Microscope (SEM) S8000 (manufactured by Hitachi, ltd.) running at 10 kV. Samples of FE-SEM were prepared by dropping a suspension of polymer flakes (containing the counter anion) in DCM and ethanol (1: 1) onto the surface of freshly cleaved mica. Transmission Electron Microscopy (TEM) analysis was performed using a JEOL JEM 2100F HRTEM. Samples of TEM were prepared by drop-coating a suspension of polymer flakes in DCM and ethanol (1: 1) onto a 150 mesh carbon-coated copper mesh and drying it overnight under vacuum.

(Infrared (IR) Spectroscopy)

FT-IR measurements were performed by a Nicolet 4700FT-IR spectrophotometer equipped with a cadmium mercury telluride (MCT) detector, and transmittance measurements were monitored using KBr chips.

(evaluation of electrochemical and electrochromic Properties)

All electrochemical experiments, including Cyclic Voltammetry (CV) and amperometric measurements, were performed using an ALS/CHI electrochemical workstation (CH Instruments, Inc.). For CV measurement, a conventional 3-electrode system was used (ITO substrate as working electrode, platinum sheet (platinum flag) as counter electrode, and nanosheet with Ag/AgCl deposited thereon as reference electrode).

(powder X-ray diffraction (PXRD))

Polymer 1 (BP-1-Fe) containing was measured by a Rigaku RINT 1200 diffractometer using Ni filtered CuK alpha radiation (λ ═ 1.5418 angstroms) at an operating voltage of 40kV and a beam current of 30mA²⁺) And a sheet containing polymer 2 (BP-2-Fe)^{2 +}) Powder X-ray diffraction (PXRD) pattern of the sheet of (a).

The results are shown in fig. 22. Based on these results, it was found that the polymer 1 (BP-1-Fe) was contained²⁺) And a sheet containing polymer 2 (BP-2-Fe)²⁺) The sheet of (a) is amorphous.

List of reference numerals

100 electrochromic element

101 first transparent electrode

102 layer of the composition

103 polymer solid electrolyte

104 second transparent electrode