Electrochromic element

Abstract

To provide an electrochromic element having excellent durability under repetitive use and photodurability.SOLUTION: An electrochromic element 10A includes a first electrode 12, a second electrode 16 facing the first electrode across a gap, and an electrolyte layer 14A between the first and second electrodes, where a first electrochromic layer 13 including an electrochromic compound represented by general formula (1) is disposed on the first electrode 12.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electrochromic device. [Background technology]

[0002] Electrochromic elements that use electrochromic materials (electrochromic compounds) that cause electrochromism to develop or fade (hereinafter referred to as "development and fading of color") are being researched and developed as promising candidates for display devices such as electronic paper and light-shielding means.

[0003] Such an electrochromic element has an electrolyte layer and an electrochromic layer containing an electrochromic compound between a pair of electrodes, and the electrochromic element develops or fades the color of the electrochromic compound by applying a forward or reverse voltage.

[0004] In principle, the electrochromic element can reversibly change between a colorless state and a colored state. Since electrochromic elements can produce various colors by stacking color-producing layers in multiple colors, such as cyan (C), magenta (M), and yellow (Y), they are expected to be elements capable of multicolor display. Therefore, in order to use electrochromic elements in transparent display devices or devices capable of multicolor display, the electrochromic compound must be composed of a material that is colorless and transparent in the decolorized state.

[0005] As an electrochromic material that is transparent in a neutral state and develops color in an oxidized state, for example, an electrochromic element using a polymer obtained by polymerizing an electrochromic composition containing triarylamine has been proposed (see, for example, Patent Document 1). Furthermore, a polymerizable organic electroluminescence (EL) light-emitting material similar to the present invention has been proposed (see, for example, Patent Document 2). Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide an electrochromic device having excellent durability against repeated use and durability against light. [Means for solving the problem]

[0007] The electrochromic element of the present invention, which is a means for achieving the above object, is an electrochromic element having a first electrode, a second electrode facing the first electrode at a distance, and an electrolyte layer provided between the first electrode and the second electrode, and has a layer containing an electrochromic compound represented by the following general formula (1) on the first electrode: [ka] In the general formula (1), R1 to R4 are all monovalent organic groups that do not have a hydrogen atom at the benzyl position, One of them is at the end Polymerizable functional group (wherein R 1 ~R 4 (excluding the case where all four of the above are groups having polymerizable functional groups), R5~R 28 represents a hydrogen atom, an alkyl group, or an alkoxy group, and R 25 and R 28 or R 26 and R 27 may be bonded to each other to form a structure represented by the following general formula (2). [ka] However, in the general formula (2), R 29 and R 30 represents an alkyl group, an alkoxy group, or an aryl group, and R 29 and R 30 When both of the groups are aryl groups, they may form a cyclic structure via a common bond. [Effects of the Invention]

[0008] According to the present invention, an electrochromic device having excellent durability against repeated use and light resistance can be provided. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing an example of the layer structure of the electrochromic element according to the first embodiment. [Figure 2] FIG. 2 is a schematic diagram showing an example of the layer structure of the electrochromic element according to the second embodiment. [Figure 3] FIG. 3 is a diagram showing the ultraviolet-visible absorption spectrum of the electrochromic element of Example 1-1 when it develops color. [Figure 4] FIG. 4 is a diagram showing the ultraviolet-visible absorption spectrum of the electrochromic element of Example 1-2 when it develops color. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Electrochromic element) The electrochromic device of the present invention comprises a first electrode, a second electrode, an electrolyte layer provided between the first electrode and the second electrode, and may further comprise other members as required.

[0011] The electrochromic element has, on a first electrode, (1) a layer containing the electrochromic compound of the present invention or a layer containing the electrochromic composition of the present invention, or (2) an electrolyte layer containing the electrochromic compound of the present invention or the electrochromic composition of the present invention.

[0012] The conventional technology in Patent Document 1 (JP 2016-038572 A) describes improvements in light durability that enable more stable operation than conventional technology and suppress the decrease in light transmittance, but the durability is not sufficient under more severe conditions such as outdoor use. Until now, regarding an electrochromic material having a benzidine skeleton that may contain a polymerizable group, the prior art Patent Document 2 (JP 2013-209300 A) has only disclosed its use as an organic electroluminescence (EL) material, but has not disclosed any properties when used as an electrochromic material. Furthermore, in Patent Document 2, the polymerizable group undergoes ring-opening polymerization of an epoxy group, oxetane, or the like, which is significantly different from the polymerizable functional group used in the electrochromic compound of the present invention.

[0013] The present inventors have focused on a specific structure, namely, a benzidine skeleton which may contain a polymerizable group, and have conducted extensive research into electrochromic materials which exhibit an orange color due to the electrochromic phenomenon. As a result, they have found that an electrochromic compound having a tetraarylbenzidine skeleton in which two triarylamines are linked can solve the above-mentioned problems. Therefore, the electrochromic device of the present invention has excellent light durability and cyclic durability, and satisfies the required physical properties of the electrochromic device. By applying the electrochromic compound or the electrochromic composition of the present invention under the optimal configuration conditions and at the optimal configuration position of the electrochromic device, the electrochromic device of the present invention can have better effects than conventional electrochromic devices, particularly excellent cyclic durability and light durability.

[0014] First, the electrochromic compound of the present invention and the electrochromic composition of the present invention, which are used in the electrochromic device of the present invention, will be described.

[0015] (electrochromic compounds) The electrochromic compound of the present invention has a tetraarylbenzidine skeleton in which two triarylamines are linked together. The electrochromic compound of the present invention refers to a compound having a tetraphenylbenzidine skeleton in which the nitrogen atoms constituting the tetraarylbenzidine skeleton are substituted with four phenyl groups.

[0016] The electrochromic compound of the present invention is preferably a radical polymerizable compound represented by the following general formula (1) and having a tetraarylbenzidine skeleton.

[0017] [ka] In the general formula (1), R1 to R4 are all monovalent organic groups that do not have a hydrogen atom at the benzyl position, and may have a polymerizable functional group as a partial structure. R5~R 28 represents a hydrogen atom, an alkyl group, or an alkoxy group, and R 25 and R 28 or R 26 and R 27 may be bonded to each other to form a structure represented by the following general formula (2).

[0018] [ka] However, in the general formula (2), R 29 and R 30 represents an alkyl group, an alkoxy group, or an aryl group, and R 29 and R 30 When both of the groups are aryl groups, they may form a cyclic structure via a common bond.

[0019] In the general formula (1), R1 to R4 are all monovalent organic groups that do not have a hydrogen atom at the benzyl position (i.e., are not CH2-X-, where X represents any monovalent organic group), and may have a polymerizable functional group as a partial structure. R5~R 28 represents a hydrogen atom, an alkyl group, or an alkoxy group, and R 25 and R 28 or R 26 and R 27 may be bonded to each other to form the structure represented by the above general formula (2). However, R1 to R 26Any one of the groups is a group containing a polymerizable functional group.

[0020] Examples of the monovalent organic group include a hydroxyl group, a nitro group, a cyano group, a carboxyl group, a carbonyl group, an amido group, an aminocarbonyl group, a sulfonic acid group, a sulfonyl group, a sulfonamide group, an aminosulfonyl group, an amino group, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, a heteroaryl group, and a silyl group. These groups may have a substituent.

[0021] Examples of the monovalent organic group having a substituent include substituted carbonyl groups such as an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylcarbonyl group, an arylcarbonyl group, a monoalkylaminocarbonyl group, a dialkylaminocarbonyl group, a monoarylaminocarbonyl group, or a diarylaminocarbonyl group; substituted sulfonyl groups such as an alkoxysulfonyl group, an aryloxysulfonyl group, an alkylsulfonyl group, an arylsulfonyl group, a sulfonamide group, a monoalkylaminosulfonyl group, a dialkylaminosulfonyl group, a monoarylaminosulfonyl group, or a diarylaminosulfonyl group; and substituted alkylamino groups such as a monoalkylamino group or a dialkylamino group.

[0022] Examples of the substituent include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, and a heteroaryl group.

[0023] Among these substituents, alkyl groups having 1 or more carbon atoms, alkenyl groups having 2 or more carbon atoms, alkynyl groups having 2 or more carbon atoms, aryl groups having 6 or more carbon atoms, heteroaryl groups having 2 or more carbon atoms, alkoxy groups, aryloxy groups, and heteroaryloxy groups are preferred.

[0024] As the alkyl group having 1 or more carbon atoms, for example, from the viewpoint of availability of raw materials, a linear, branched, or cyclic alkyl group having 1 to 30 carbon atoms is preferred. Among cyclic alkyl groups having 1 to 30 carbon atoms, a cyclic alkyl group having 1 to 18 carbon atoms is more preferred.

[0025] Examples of alkyl groups having one or more carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a tert-butyl group, an isopropyl group, an isobutyl group, a pentyl group, a hexyl group, a heptyl group, an ethylhexyl group, an octyl group, a decyl group, a dodecyl group, a 2-butyloctyl group, an octadecyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and an adamantyl group.

[0026] The alkenyl group having 2 or more carbon atoms is preferably, for example, a linear, branched, or cyclic alkenyl group having 2 to 30 carbon atoms. Among cyclic alkenyl groups having 2 to 30 carbon atoms, cyclic alkenyl groups having 2 to 18 carbon atoms are more preferred.

[0027] An alkenyl group having two or more carbon atoms is a substituent obtained by removing two arbitrary hydrogen atoms from an alkyl group having one or more carbon atoms. Examples of alkenyl groups having two or more carbon atoms include a vinyl group (ethenyl group), a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptanyl group, an octenyl group, a decenyl group, a dodecenyl group, an octadecenyl group, a cyclobutenyl group, a cyclopentenyl group, and a cyclohexenyl group.

[0028] The alkynyl group having 2 or more carbon atoms is preferably, for example, a linear, branched, or cyclic alkynyl group having 2 to 30 carbon atoms. Among cyclic alkynyl groups having 2 to 30 carbon atoms, cyclic alkynyl groups having 2 to 18 carbon atoms are more preferred.

[0029] An alkynyl group having two or more carbon atoms is a substituent obtained by removing any four hydrogen atoms from an alkyl group having one or more carbon atoms. Examples of alkynyl groups having two or more carbon atoms include an ethynyl group, a propynyl group, a butynyl group, a pentynyl group, a hexynyl group, a heptynyl group, an octynyl group, a decynyl group, a dodecynyl group, and an octadecynyl group.

[0030] Examples of aryl groups having 6 or more carbon atoms include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a p-chlorophenyl group, a p-fluorophenyl group, a p-trifluorophenyl group, a naphthyl group, a biphenyl group, an anthryl group, a phenanthryl group, a pyrenyl group, a fluorenyl group, a benzopyrenyl group, and a chrysenyl group.

[0031] As the heteroaryl group having 2 or more carbon atoms, for example, a heteroaryl having 2 to 12 carbon atoms is preferable.

[0032] Examples of constituent elements of the heteroaryl group having two or more carbon atoms include a nitrogen atom, a sulfur atom, an oxygen atom, a silicon atom, a selenium atom, etc. Among these, it is preferable that the heteroaryl group contains any one atom selected from a nitrogen atom, a sulfur atom, and an oxygen atom.

[0033] Examples of heteroaryl groups having two or more carbon atoms include monocyclic heteroaryl groups and polycyclic heteroaryl groups.

[0034] Examples of the monocyclic heteroaryl group include a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a tetrazine ring, a thiophene ring, a furan ring, pyrrole, imidazole, pyrazole, a thiazole ring, an oxazole ring, an isoxazole, an oxadiazole ring, a triazine ring, a tetrazole ring, and a triazole ring.

[0035] Examples of polycyclic heteroaryl groups include quinoline, isoquinoline, quinalizone, phthalazine, indole, benzothiophene, benzofuran, benzimidazole, benzothiodiazole, acridine, phenoxazine, phenothiazine, carbazole, benzodithiophene, benzodifuran, dibenzofuran, and dibenzothiophene groups.

[0036] The polycyclic heteroaryl group may be a group in which an aryl group and a heteroaryl group are bonded via a covalent bond or a group in which an aryl group and a heteroaryl group are fused to each other. Examples of the group in which an aryl group and a heteroaryl group are bonded via a covalent bond or a group in which an aryl group and a heteroaryl group are fused to each other include a biphenyl group, a terphenyl group, a 1-phenylnaphthalene group, and a 2-phenylnaphthalene group.

[0037] In the general formula (1), the polymerizable functional group may be any group that has a carbon-carbon double bond and is polymerizable. Examples of the polymerizable functional group include the following 1-substituted ethylene functional groups and 1,1-substituted ethylene functional groups.

[0038] (1) Examples of the 1-substituted ethylene functional group include functional groups represented by the following general formula (i):

[0039] [ka]

[0040] In the general formula (i), X1 is an arylene group, an alkenylene group, a -CO- group, a -COO- group, a -CON(R 100 )-group(R 100 represents a hydrogen atom, an alkyl group, an aralkyl group, or an aryl group. ) or an S-group. The arylene group or alkenylene group may have a substituent.

[0041] Examples of the arylene group include a phenylene group and a naphthylene group. The phenylene group may have a substituent.

[0042] Examples of the alkenylene group include an ethenylene group, a propenylene group, and a butenylene group.

[0043] Examples of the alkyl group include a methyl group and an ethyl group.

[0044] Examples of the aralkyl group include a benzyl group, a naphthylmethyl group, and a phenethyl group.

[0045] Examples of the aryl group include a phenyl group and a naphthyl group.

[0046] Specific examples of the functional group represented by general formula (i) include a vinyl group, a styryl group, a 2-methyl-1,3-butadienyl group, a vinylcarbonyl group, an acryloyloxy group, an acryloylamide group, and a vinylthioether group.

[0047] (2) Examples of the 1,1-substituted ethylene functional group include functional groups represented by the following general formula (ii):

[0048] [ka]

[0049] In the general formula (ii), Y is an alkyl group, an aralkyl group, an aryl group, a halogen atom, a cyano group, a nitro group, an alkoxy group, or -COOR 101 Group(R 101 is a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, or CONR 102 R 103 (R 102 or R 103 represents a hydrogen atom, an alkyl group, an aralkyl group or an aryl group, which may be the same or different from each other. )) represents. Any of these groups may have a substituent. Furthermore, X2 represents the same substituent or alkylene group as X1 in general formula (i), provided that at least one of Y and X2 is an oxycarbonyl group, a cyano group, an alkenylene group, or an aromatic ring.

[0050] Examples of alkyl groups include methyl groups and ethyl groups. Examples of aralkyl groups include benzyl groups, naphthylmethyl groups, and phenethyl groups. Examples of aryl groups include phenyl groups and naphthyl groups. Examples of alkoxy groups include methoxy groups or ethoxy groups, as well as diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, tetraethylene glycol, tetrapropylene glycol, polyethylene glycol, and polypropylene glycol, which are condensed with ethylene glycol units or propylene glycol.

[0051] Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0052] Specific examples of the polymerizable functional group represented by general formula (ii) include an α-acryloyloxy chloride group, a methacryloyloxy group, an α-cyanoethylene group, an α-cyanoacryloyloxy group, an α-cyanophenylene group, and a methacryloylamino group.

[0053] Examples of substituents that may be further substituted on these substituents for X1, X2, and Y include halogen atoms; alkyl groups such as a nitro group, a cyano group, a methyl group, or an ethyl group; alkoxy groups such as a methoxy group or an ethoxy group; aryloxy groups such as a phenoxy group; aryl groups such as a phenyl group or a naphthyl group; and aralkyl groups such as a benzyl group or a phenethyl group.

[0054] Among the functional groups represented by the general formula (i) or (ii), a (meth)acryloyl group or a (meth)acryloxy group is preferred, and an acryloyl group or an acryloyloxy group is more preferred. This is because the high polymerization rate allows complete curing to the inside of the electrochromic layer with a shorter irradiation time and energy, and also because polymerizable phase separation is less likely to occur, which is advantageous for the electrochromic device characteristics.

[0055] In the general formula (1) above, the polymerizable functional group is preferably substituted at the end of, for example, an alkyl or alkoxy group having 1 or more carbon atoms, an aryl or phenoxy group having 6 or more carbon atoms, or an aryl group having 7 or more carbon atoms and substituted with an alkyl or alkoxy group, from the viewpoint of high resistance to oxidation and reduction, more preferably at the end of an alkyl or alkoxy group, and most preferably an alkoxy group having no hydrogen atom at the benzyl position. The alkyl group and alkoxy group preferably have 3 or more carbon atoms.

[0056] The polymerizable functional group is preferably bonded to the main skeleton of the present invention via an alkyl group having at least two carbon atoms.

[0057] R1 to R4 are all monovalent organic groups that do not have hydrogen at the benzyl position (i.e., are not CH2-X-, where X represents any monovalent organic group), and may have the polymerizable functional group as a partial structure. It is preferably selected from the group consisting of a halogen atom, a monovalent organic group, and a polymerizable functional group, because the para-position of the nitrogen atom in the triphenylamine skeleton has high electron density and is reactive, and therefore it is preferable to substitute this site with a halogen atom, a monovalent organic group, or a polymerizable functional group other than a hydrogen atom.

[0058] In JP 2016-038572 A (Patent Document 1) and other publications, it is said that if hydrogen atoms remain at the para-position of the benzene ring substituted with the nitrogen atom of triphenylamine or benzidine, polymerization occurs during oxidation-reduction, and the electrical and optical properties change, and therefore, substitution with an alkyl group or an alkoxy group provides greater electrical and optical stability.

[0059] As a result of extensive research, the inventors of the present invention have concluded that compounds with structures substituted with methyl groups, such as those shown below, or compounds having polymerizable groups via alkyl groups, are susceptible to reaction with oxygen due to the high reactivity of the benzyl position. In fact, a supporting electrolyte, a compound that develops color in the oxidized state, and trace amounts of oxygen were placed in a solvent, and the solution was irradiated with light (150,000 lux for 15 hours). After the solution was analyzed by HPLC-MS / MS (Thermo Scientific), oxidation reactions at the benzyl position were confirmed even in compounds with terminal methyl groups or polymerizable functional groups via alkyl groups, such as those shown below. This may be due to a reaction between a molecule in an oxidized state (i.e., a radical cation state) and a neutral molecule. This reaction is particularly pronounced under light irradiation, and it is thought that the radical cation molecule acts as a visible light redox catalyst to promote the oxidation reaction.

[0060] <Optical deterioration (yellowing)> It was confirmed that the absorption wavelength range of a compound in which one part of a benzidine compound is oxidized extends to around 450 nm. In other words, since one of the factors that causes optical deterioration (yellowing) under light irradiation is the mechanism expressed by the following formula, we investigated ways to prevent this.

[0061] [ka] [ka]

[0062] The monovalent organic group that does not have a hydrogen atom at the benzyl position (i.e., is not CH2-X-, where X represents any monovalent organic group) must be a group that is not susceptible to oxidation when bonded to the para position of benzidine. One way to achieve such a group is to simply insert another atom other than -CH2-. However, groups that can be oxidized by an appropriate oxidizing agent such as hydrogen peroxide, such as sulfur atoms, phosphorus atoms, or selenium atoms, are not preferred. The preferred form is -YX- (where Y is an atom other than a carbon atom), which has no carbon atoms, or -CZ2-X- (where Z is a monovalent organic group other than a hydrogen atom). Y and Z2 are preferably groups that do not have much electronic influence on the main skeleton of benzidine, and strong electron-withdrawing groups such as halogen atoms, cyano groups, and nitro groups are not preferred. Such a group not having a hydrogen atom at the benzyl position is preferably any one of a tertiary butyl group, a trialkylsilyl group, a triarylsilyl group, a diallylmonoalkylsilyl group, an alkoxy group, and a phenoxy group. Among the above substituents, alkoxy groups have the highest electron-donating properties derived from oxygen and are effective in significantly lowering the oxidation potential of the benzidine compound. As in the present invention, these groups suppress yellowing of the compound itself under light irradiation and also have favorable effects such as lowering the driving voltage. However, the introduction of an excessive number of alkoxy groups may result in an excessively low oxidation potential, making the electrochromic compound unstable to oxygen. Therefore, the number of alkoxy groups introduced into R1 to R4 is preferably 2 or less. Meanwhile, since phenoxy groups have electron-donating properties similar to those of alkyl groups, there is no limit to the number of alkoxy groups that can be introduced. That is, when the monovalent organic group not having a hydrogen atom at the benzyl position in R1 to R4 is selected from a tertiary butyl group, a trialkylsilyl group, a triarylsilyl group, a diallylmonoalkylsilyl group, an alkoxy group, and a phenoxy group, it is preferable that there are 0 to 2 alkoxy groups.

[0063] R1~R 28It is preferable that at least one of the above is a polymerizable functional group. This is because, when the electrochromic compound of the present invention is used as a polymerized film, polymerizability can be imparted to the electrochromic compound and a substituent can be easily introduced.

[0064] When a polymerizable group is present, R1 to R4 or R 25 ~R 28 R that occurs as a result of combining 29 ,R 30 It is more preferable that one or more of the above be a polymerizable functional group, since this does not cause steric distortion and can be easily introduced in advance.

[0065] [ka]

[0066] Also, R5~R 12 is preferably any one of an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a halogen atom, or a polymerizable functional group, from the viewpoints of not causing a change in color and suppressing side reactions between molecules during color development.

[0067] R1~R 12 is a monovalent organic group, the monovalent organic group is more preferably an alkyl group having 1 or more carbon atoms, an alkenyl group having 2 or more carbon atoms, an alkynyl group having 2 or more carbon atoms, an aryl group having 6 or more carbon atoms, a heteroaryl group having 2 or more carbon atoms, an alkoxy group having 1 or more carbon atoms, an aryloxy group, or a heteroaryloxy group.

[0068] R1~R 12may be a group in which one or more aryl groups or heteroaryl groups are bonded via a covalent bond, or a group in which one or more aryl groups or heteroaryl groups are fused to each other. A group in which one or more aryl groups or heteroaryl groups are bonded via a covalent bond, or a group in which one or more aryl groups or heteroaryl groups are fused to each other, has a total carbon number of 1 to 100 and may contain a heteroatom. The upper limit of the total carbon number is preferably 50, more preferably 36. Examples of heteroatoms include an oxygen atom, a sulfur atom, and a nitrogen atom.

[0069] In consideration of the transparency of the electrochromic compound when it is bleached, the absorption edge of the group in which one or more aryl groups and heteroaryl groups are bonded via a covalent bond or the group in which one or more aryl groups and heteroaryl groups are fused to each other is preferably 400 nm or shorter, more preferably 380 nm or shorter, alone.

[0070] The number of groups in which aryl groups and heteroaryl groups are bonded via a covalent bond or groups in which aryl groups and heteroaryl groups are fused to each other can be selected from the range of 1 to 6, preferably 1 to 3, and more preferably 1 to 2. A significant increase in the number of groups in which aryl groups and heteroaryl groups are bonded via a covalent bond or groups in which aryl groups and heteroaryl groups are fused to each other, which do not contribute to color development relative to triphenylamine belonging to the chromophore, is undesirable from the viewpoints of color development efficiency and material costs.

[0071] R 13 ~R 28 R is also preferably selected from the group consisting of a hydrogen atom, a halogen atom, a monovalent organic group, and a polymerizable functional group. 13 ~R 28 is preferably substituted with a halogen atom, a monovalent organic group, or a polymerizable functional group. 10 ~R 15is more preferably an alkyl group, an alkoxy group, an aryl group, a heteroaryl group, a halogen atom, or a polymerizable functional group, and most preferably an alkyl group, an alkoxy group, an aryl group, or a polymerizable functional group. The polymerizable functional group is preferably present as a part of the alkyl group or aryl group, particularly at the terminal.

[0072] <Second Preferred Form> R 13 From R 24 are preferably all hydrogen atoms. This is because the absence of a substituent prevents steric distortion of the phenyl group bonded to the nitrogen atom of benzidine. Furthermore, halogen atoms and the like, which have small atomic sizes, do not cause steric distortion, but are highly electron-withdrawing, which increases the oxidation potential of the benzidine compound, making them undesirable.

[0073] [ka]

[0074] <Third Preferred Form> [ka] In the above general formula, R 25 From R 28 is a halogen atom or a hydrogen atom, or R 25 From R 28 are preferably bonded to each other to form a structure represented by the following general formula (2), or a cyclic ether structure such as dibenzofuran via an oxygen atom, or a structure such as dibenzothiophene via a sulfur atom, and are more preferably either a hydrogen atom or a structure represented by the general formula (2). [ka] However, in the general formula (2), R 29 and R 30 represents an alkyl group, an alkoxy group, or an aryl group, and R 27 and R 28When both of the groups are aryl groups, they may form a cyclic structure via a common bond.

[0075] Examples of the electrochromic compound represented by the general formula (1) include the following exemplary compounds. The electrochromic compound of the present invention is not limited to these. In the exemplary compounds shown below, MeO- represents a methoxy group.

[0076] <Example Compound 1> [ka]

[0077] <Example Compound 2> [ka]

[0078] <Example Compound 3> [ka]

[0079] <Example Compound 4> [ka]

[0080] <Example Compound 5> [ka]

[0081] <Example Compound 6> [ka]

[0082] <Example Compound 7> [ka]

[0083] <Exemplary compound 8>

change

[0084] <Exemplary Compound 9>

change

[0085] <Exemplary Compound 10>

change

[0086] <Exemplary compound M1>

change

[0087] <Exemplary Compound M2>

change

[0088] <Exemplary compound M3>

change

[0089] <Exemplary Compound M4>

change

[0090] <Exemplary compound M5>

change

[0091] (Electrochromic Composition) The electrochromic composition of the present invention contains the electrochromic compound of the present invention, and preferably further contains another radically polymerizable compound.

[0092] The electrochromic compound of the present invention is a radical polymerizable compound having a tetraarylbenzidine skeleton, and is therefore important for imparting electrochromic functionality having a redox reaction to the surface of the first electrode of an electrochromic device.

[0093] The electrochromic composition of the present invention preferably contains a radically polymerizable compound other than the electrochromic compound of the present invention.

[0094] <Triphenylamine compounds> The electrochromic composition of the present invention can further contain a triphenylamine compound as another radically polymerizable compound. By containing the triphenylamine compound, the electrochromic composition of the present invention is transparent in a neutral state and can exhibit stable optical properties (typically a color that is a combination of orange and blue) in a one-electron oxidation state.

[0095] In the triphenylamine compound, the para positions of the three phenyl groups bonded to the nitrogen atom are preferably substituted with a substituent other than hydrogen, such as an alkyl group, an alkoxy group, or a radically polymerizable substituent. Triphenylamine compounds with hydrogen at the terminal end may react and polymerize in a one-electron oxidation state. Upon polymerization, the triphenylamine compound becomes a benzidine compound, and its color is known to change from blue to orange. Substitution of the para positions of the three phenyl groups bonded to the nitrogen atom with a substituent other than hydrogen can improve the electrochemical stability of the triphenylbenzidine compound. This prevents the triphenylamine compound from polymerizing in a one-electron oxidation state, thereby suppressing color changes during color development and thereby exhibiting stable optical properties.

[0096] Furthermore, it is preferable that the ortho-position relative to the nitrogen atom of the benzene constituting the triphenylamine is bonded via a spacer. Examples of the spacer include a carbon atom, a silicon atom, etc., and the substituent on these may be substituted with an alkyl group or an aryl group. In such a bridged triphenylamine, the ortho-position, which is reactive with respect to the para-position, is blocked, and therefore, further improvement in electrochemical durability can be expected.

[0097] The triphenylamine compound can be used as it is or can be copolymerized. Therefore, the triphenylamine compound may have a radical polymerizable substituent. The radical polymerizable substituent can be appropriately changed within the same range as that of the electrochromic compound of the present invention, and may be present in a part of the tetraphenylbenzidine compound, such as the terminal of an alkyl group or alkoxy group at the para position. An acryloyloxy group or a methacryloyloxy group is preferred, and an acryloyloxy group is more preferred.

[0098] In a neutral state, the triphenylamine compound is transparent in the visible region, i.e., the absorption edge of the ultraviolet-visible absorption spectrum is preferably 420 nm or less, more preferably 410 nm or less, and most preferably 400 nm or less. In addition, the triphenylamine compound preferably develops a blue or cyan color upon one-electron oxidation, and the peak wavelength in the visible region (380 nm to 780 nm) is preferably around 550 nm to 700 nm, with the absorption edge on the short wavelength side preferably being 450 nm to 500 nm. The absorption edge on the long wavelength side preferably being 650 nm to 800 nm. This is because, when the triphenylamine compound is combined with the electrochromic compound of the present invention, which develops an orange color, the complementary absorption in the visible region enables black color development.

[0099] Specific examples of triphenylamine compounds that can satisfy the above optical properties include, but are not limited to, the following: In the following example compounds, MeO- represents a methoxy group.

[0100] <Example compound TPA1> [ka]

[0101] <Example compound TPA2> [ka]

[0102] <Example compound TPA3> [ka]

[0103] <Example compound TPA4> [ka]

[0104] <Example compound TPA5> [ka]

[0105] <Example compound TPA6> [ka]

[0106] <Example compound TPA7> [ka]

[0107] <Example compound TPA8>

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[0108] <Exemplary compound TPA9>

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[0109] <Exemplary compound TPA10>

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[0110] <Exemplary compound TPA11>

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[0111] <Exemplary compound TPA12>

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[0112] <Exemplary compound TPA13>

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[0113] <Exemplary compound TPA14>

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[0114] <Exemplary compound TPA15>

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[0115] <Exemplary compound TPA16>

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[0116] <Exemplary compound TPA17>

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[0117] <Exemplary compound TPA18>

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[0118] <Exemplary compound TPA19>

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[0119] <Exemplary compound TPA20>

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[0120] <Exemplary compound TPA21>

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[0121] <Exemplary compound TPA22>

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[0122] <Exemplary compound TPA23>

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[0123] <Exemplary compound TPAM1>

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[0124] <Exemplary compound TPAM2>

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[0125] <Exemplary compound TPAM3>

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[0126] <Exemplary compound TPAM4>

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[0127] <Exemplary compound TPAM5>

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[0128] <Exemplary compound TPAM6>

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[0129] <Exemplary compound TPAM7>

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[0130] <Exemplary compound TPAM8>

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[0131] <Exemplary compound TPAM9>

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[0132] <Exemplary compound TPAM10>

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[0133] <Example compound TPAM11> [ka]

[0134] Examples of other radical polymerizable compounds other than the electrochromic compound of the present invention and the triphenylamine compound include monofunctional radical polymerizable compounds, bifunctional radical polymerizable compounds, trifunctional or higher functional radical polymerizable compounds, functional monomers, and radical polymerizable oligomers. Among these, bifunctional or higher functional radical polymerizable compounds are particularly preferred. The radical polymerizable functional groups in the other radical polymerizable compounds are the same as the radical polymerizable functional groups in the electrochromic compound according to the embodiment. Among these, acryloyloxy and methacryloyloxy groups are preferred, with acryloyloxy groups being particularly preferred.

[0135] Examples of monofunctional radical polymerizable compounds include 2-(2-ethoxyethoxy)ethyl acrylate, methoxypolyethylene glycol monoacrylate, methoxypolyethylene glycol monomethacrylate, phenoxypolyethylene glycol acrylate, 2-acryloyloxyethyl succinate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-ethylhexyl carbitol acrylate, 3-methoxybutyl acrylate, benzyl acrylate, cyclohexyl acrylate, isoamyl acrylate, isobutyl acrylate, methoxytriethylene glycol acrylate, phenoxytetraethylene glycol acrylate, cetyl acrylate, isostearyl acrylate, stearyl acrylate, and styrene monomers. These may be used alone or in combination of two or more.

[0136] Examples of bifunctional radically polymerizable compounds include 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, diethylene glycol diacrylate, polyethylene glycol diacrylate, neopentyl glycol diacrylate, EO-modified bisphenol A diacrylate, EO-modified bisphenol F diacrylate, and neopentyl glycol diacrylate. These may be used alone or in combination of two or more.

[0137] Examples of the trifunctional or higher radical polymerizable compound include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, EO-modified trimethylolpropane triacrylate, PO-modified trimethylolpropane triacrylate, caprolactone-modified trimethylolpropane triacrylate, HPA-modified trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate, ECH-modified glycerol triacrylate, EO-modified glycerol triacrylate, PO-modified glycerol triacrylate, and trimethylolpropane trimethacrylate. Examples of suitable acrylates include thi(acryloxyethyl)isocyanurate, dipentaerythritol hexaacrylate (DPHA), caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkyl-modified dipentaerythritol pentaacrylate, alkyl-modified dipentaerythritol tetraacrylate, alkyl-modified dipentaerythritol triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxy tetraacrylate, EO-modified phosphate triacrylate, and 2,2,5,5-tetrahydroxymethylcyclopentanone tetraacrylate. These may be used alone or in combination of two or more. In the above, EO-modified refers to ethyleneoxy-modified, and PO-modified refers to propyleneoxy-modified.

[0138] Examples of functional monomers include fluorine atom-substituted monomers such as octafluoropentyl acrylate, 2-perfluorooctylethyl acrylate, 2-perfluorooctylethyl methacrylate, and 2-perfluoroisononylethyl acrylate; vinyl monomers having polysiloxane groups, such as acryloylpolydimethylsiloxane ethyl, methacryloylpolydimethylsiloxane ethyl, acryloylpolydimethylsiloxane propyl, acryloylpolydimethylsiloxane butyl, and diacryloylpolydimethylsiloxane diethyl, each having 20 to 70 siloxane repeating units, as described in Japanese Patent Publication Nos. 5-60503 and 6-45770; and acrylates or methacrylates. These may be used alone or in combination of two or more.

[0139] Examples of the radically polymerizable oligomer include epoxy acrylate oligomers, urethane acrylate oligomers, and polyester acrylate oligomers.

[0140] The electrochromic compound of the present invention and other radically polymerizable compounds can be copolymerized by a polymerization reaction. It is preferable that at least one of them has two or more radically polymerizable functional groups in order to form a polymerized or crosslinked product. The polymerized or crosslinked product is preferable in that it is not dissolved in various organic solvents or electrolytes, etc., and has little interlayer migration when forming a multilayer structure, in addition to its mechanical strength.

[0141] The content of the electrochromic compound of the present invention is preferably 10% by mass or more and 100% by mass or less, and more preferably 30% by mass or more and 90% by mass or less, based on the total amount of the electrochromic composition. When the content is 10% by mass or more, the electrochromic function of the first electrochromic layer in the electrochromic element can be fully exhibited, and the durability and color development sensitivity are good with repeated use under applied voltage. When the content is 100% by mass or less, the electrochromic function of the first electrochromic layer can be exhibited, and the color development sensitivity relative to the thickness is sufficiently high. Furthermore, when the content is 100% by mass, the compatibility between the electrochromic compound and the ionic liquid necessary for charge transfer may be reduced, which may result in deterioration of electrical properties due to reduced durability with repeated use under applied voltage. The required electrical properties vary depending on the process in which the electrochromic compound is used. However, considering the balance between color development sensitivity and repeated use durability, the content is more preferably 30% by mass or more and 90% by mass or less.

[0142] The electrochromic composition of the present invention preferably contains a filler and a polymerization initiator.

[0143] <Filler> The filler is not particularly limited and can be appropriately selected depending on the purpose. Examples of the filler include inorganic fillers and organic fillers.

[0144] Examples of inorganic fillers include metal powders such as copper, tin, aluminum, and indium; metal oxides such as silicon oxide (silica), tin oxide, zinc oxide, titanium oxide, aluminum oxide (alumina), zirconium oxide, indium oxide, antimony oxide, bismuth oxide, calcium oxide, antimony-doped tin oxide (ATO), and tin-doped indium oxide; and metal fluorides such as tin fluoride, calcium fluoride, and aluminum fluoride. These may be used alone or in combination of two or more. Among these, metal oxides are preferred from the viewpoints of transparency, stability, ease of surface treatment, and the like, and silica, alumina, and antimony-doped tin oxide (ATO) are particularly preferred.

[0145] Examples of organic fillers include resins such as polyester, polyether, polysulfide, polyolefin, silicone, or polytetrafluoroethylene; low molecular weight compounds such as fatty acids; and pigments such as phthalocyanine. These may be used alone or in combination of two or more. Among these, resins are preferred in terms of transparency and insolubility. The average primary particle size of the filler is preferably 1 μm or less, and more preferably 10 nm or more and 1 μm or less. When the average primary particle size of the filler is 1 μm or less, there are no coarse particles, and the surface condition of the obtained film is good, resulting in excellent surface smoothness.

[0146] The content of the filler is preferably 0.3 to 1.5 parts by mass, more preferably 0.6 to 0.9 parts by mass, in terms of solids concentration relative to 100 parts by mass of the total amount of the radical polymerizable compound. When the content of the filler is 0.3 parts by mass or more, the effect of adding the filler is sufficiently obtained and film-forming properties are good, and when it is 1.5 parts by mass or less, the proportion of the triarylamine compound is appropriate and good electrochemical properties of the produced electrochromic device are obtained.

[0147] <Polymerization initiator> The electrochromic composition of the present invention preferably contains a polymerization initiator as needed to efficiently promote the crosslinking reaction between the electrochromic compound of the present invention and other radically polymerizable compounds. Examples of the polymerization initiator include a thermal polymerization initiator and a photopolymerization initiator, and from the viewpoint of polymerization efficiency, a photopolymerization initiator is preferred.

[0148] The thermal polymerization initiator is not particularly limited and can be appropriately selected depending on the purpose. Examples of the thermal polymerization initiator include peroxide initiators such as 2,5-dimethylhexane-2,5-dihydroperoxide, dicumyl peroxide, benzoyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di(peroxybenzoyl)hexyne-3, di-t-butylperoxide, t-butylhydroperoxide, cumenehydroperoxide, and lauroyl peroxide; and azo initiators such as azobisisobutylnitrile, azobiscyclohexanecarbonitrile, methyl azobisisobutyrate, azobisisobutylamidine hydrochloride, and 4,4'-azobis-4-cyanovaleric acid. These may be used alone or in combination of two or more.

[0149] The photopolymerization initiator is not particularly limited and can be appropriately selected depending on the purpose. Examples of the photopolymerization initiator include acetophenone-based or ketal-based photopolymerization initiators such as diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-2-morpholino(4-methylthiophenyl)propan-1-one, and 1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime; benzoin, benzophenone ... Examples of photopolymerization initiators include benzoin ether-based photopolymerization initiators such as benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether, and benzoin isopropyl ether; benzophenone-based photopolymerization initiators such as benzophenone, 4-hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether, acrylated benzophenone, and 1,4-benzoylbenzene; and thioxanthone-based photopolymerization initiators such as 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2,4-dichlorothioxanthone.

[0150] Other photopolymerization initiators include, for example, ethyl anthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,4-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, methylphenylglyoxyester, 9,10-phenanthrene, acridine compounds, triazine compounds, imidazole compounds, etc. These may be used alone or in combination of two or more.

[0151] In addition, a photopolymerization accelerator can be used alone or in combination with a photopolymerization initiator, such as triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, (2-dimethylamino)ethyl benzoate, or 4,4'-dimethylaminobenzophenone.

[0152] The content of the polymerization initiator is preferably 0.5 parts by mass or more and 40 parts by mass or less, and more preferably 1 part by mass or more and 20 parts by mass or less, relative to 100 parts by mass of the total amount of the radical polymerizable compounds.

[0153] <Other ingredients> The electrochromic composition of the present invention may further contain other components as necessary. The other components are not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a solvent, a plasticizer, a leveling agent, a sensitizer, a dispersant, a surfactant, and an antioxidant.

[0154] The electrochromic composition of the present invention may contain a crosslinking agent and may be a copolymer obtained by polymerizing the electrochromic compound of the present invention (for example, a linear copolymer having a linear structure). The electrochromic composition of the present invention may also be a crosslinked product having a branched structure or a three-dimensional network structure obtained by crosslinking the electrochromic compound of the present invention. The crosslinking agent is not particularly limited and can be appropriately selected depending on the purpose. Examples of the crosslinking agent include isocyanates, amino resins, phenolic resins, amines, epoxy compounds, monofunctional (meth)acrylates, polyfunctional (meth)acrylates having two or more ethylenically unsaturated bonds in one molecule, acrylic acid esters, and methacrylic acid esters. Among these, isocyanates are preferred, and polyisocyanates having multiple isocyanate groups are particularly preferred.

[0155] The electrochromic composition of the present invention contains the electrochromic compound of the present invention, and therefore can meet the physical properties required for an electrochromic device, such as the electrochromic composition being transparent in a neutral state, having solubility, and being capable of forming an electrochromic layer, as described above.

[0156] (Electrochromic element) As described above, the electrochromic device of the present invention has (1) a layer containing the electrochromic compound of the present invention or a layer containing the electrochromic composition of the present invention, or (2) an electrolyte layer containing the electrochromic compound of the present invention or the electrochromic composition of the present invention.

[0157] Hereinafter, an electrochromic element having a layer containing the electrochromic compound of the present invention or a layer containing the electrochromic composition of the present invention (electrochromic layer) on a first electrode will be referred to as an electrochromic element according to the first embodiment. An electrochromic element in which the electrolyte layer is a layer containing the electrochromic compound of the present invention or the electrochromic composition of the present invention is referred to as an electrochromic element according to the second embodiment. The electrochromic elements according to each embodiment will be described below.

[0158] [Electrochromic element according to the first embodiment] An electrochromic element according to a first embodiment will be described. For ease of understanding, the scale of each component in the drawings may differ from the actual scale. For convenience in explaining the layer structure, the following examples will be described with reference to figures in which the first support is disposed at the bottom, but the first embodiment will not necessarily be manufactured or used in this configuration. In the following description, one side of the thickness direction of the first support may be referred to as the top or upper side, and the other side of the thickness direction of the support may be referred to as the bottom or lower side.

[0159] Fig. 1 is a diagram showing an example of the configuration of an electrochromic element according to the first embodiment. As shown in Fig. 1, an electrochromic element 10A according to the first embodiment has a first support 11, a display electrode (first electrode) 12, a first electrochromic layer 13, an electrolyte layer 14A, a second electrochromic layer 15, a counter electrode (second electrode) 16, and a second support 17. These members are stacked in this order from the first support 11 side.

[0160] The first support 11 has a display electrode 12 on its upper surface, and the first electrochromic layer 13 is provided on the display electrode 12. On the other hand, the second support 17 has a counter electrode 16 on its lower surface, and the second electrochromic layer 15 is provided on the lower surface of the counter electrode 16. The display electrode 12 and the counter electrode 16 are provided opposite each other with a predetermined gap between them, and the electrolyte layer 14A is provided between both electrodes (the display electrode 12 and the counter electrode 16).

[0161] In the electrochromic element 10A according to the first embodiment, the first electrochromic layer 13 develops and fades color on the surface of the display electrode 12 due to an oxidation-reduction reaction, and the second electrochromic layer 15 develops and fades color on the surface of the counter electrode 16 due to an oxidation-reduction reaction.

[0162] Hereinafter, each of the members constituting the electrochromic device 10A according to the first embodiment will be described.

[0163] [First Electrochromic Layer] The first electrochromic layer contains the electrochromic compound or electrochromic composition of the present invention described above. In the first embodiment, the electrochromic compound or electrochromic composition of the present invention is referred to as the first electrochromic compound or first electrochromic composition to distinguish it from the second electrochromic compound or second electrochromic composition described below.

[0164] In the first embodiment, as described above, it is preferable that the first electrochromic composition contains the electrochromic compound of the present invention and another radically polymerizable compound, from the viewpoint of the solubility and durability of the polymer of the first electrochromic composition.

[0165] The first electrochromic layer is laminated in one layer on the first electrode, but is not limited to this and may be laminated in multiple layers.

[0166] The first electrochromic layer is laminated on the entire surface of the first electrode, but is not limited to this, and may be laminated on only a part of the first electrode.

[0167] The first electrochromic layer can be formed by a method for manufacturing an electrochromic element. The average thickness of the first electrochromic layer is preferably 0.1 μm or more and 30 μm or less, and more preferably 0.4 μm or more and 10 μm or less.

[0168] [First electrode and second electrode] The materials for the first electrode and the second electrode are not particularly limited as long as they are transparent and conductive, and can be appropriately selected depending on the purpose. Examples of materials for the first electrode and the second electrode include inorganic materials such as tin-doped indium oxide (hereinafter referred to as "ITO"), fluorine-doped tin oxide (hereinafter referred to as "FTO"), antimony-doped tin oxide (hereinafter referred to as "ATO"), and zinc oxide. Among these, InSnO, GaZnO, SnO, In2O3, and ZnO are preferred.

[0169] Furthermore, an electrode may be used that has improved conductivity while maintaining transparency by forming transparent carbon nanotubes or other highly conductive non-transparent materials such as Au, Ag, Pt, or Cu into a fine network.

[0170] The thickness of each of the first electrode and the second electrode is adjusted so as to obtain the electrical resistance value necessary for the oxidation-reduction reaction of the first electrochromic layer or the second electrochromic layer. When ITO is used as the material of the first electrode and the second electrode, the thickness of each of the first electrode and the second electrode is preferably, for example, 50 nm or more and 500 nm or less.

[0171] The first electrode and the second electrode can be formed by, for example, vacuum deposition, sputtering, ion plating, etc. There are no particular limitations on the method used as long as the materials for the first electrode and the second electrode can be applied, and various printing methods can be used, such as spin coating, casting, microgravure coating, gravure coating, bar coating, roll coating, wire bar coating, dip coating, slit coating, capillary coating, spray coating, nozzle coating, gravure printing, screen printing, flexographic printing, offset printing, reverse printing, and inkjet printing.

[0172] [Electrolyte layer] The electrolyte layer is formed by an electrolyte filled between the first electrode and the second electrode, for example, by inserting the electrolyte through a sealant having a plurality of injection holes provided between the first electrode and the second electrode, and filling the space between the first electrode and the second electrode.

[0173] Examples of electrolytes that can be used include inorganic ion salts such as alkali metal salts and alkaline earth metal salts, quaternary ammonium salts, and acid or alkali supporting salts. Specific examples include LiClO4, LiBF4, LiAsF6, LiPF6, LiCF3SO3, LiCF3COO, KCl, NaClO3, NaCl, NaBF4, NaSCN, KBF4, Mg(ClO4), and Mg(BF4)2.

[0174] Ionic liquids can also be used as electrolyte materials. Among these, organic ionic liquids are preferred because they have a molecular structure that allows them to remain liquid over a wide temperature range, including room temperature. Examples of the molecular structure of organic ionic liquids include cationic components such as imidazole derivatives, such as N,N-dimethylimidazole salts, N,N-methylethylimidazole salts, and N,N-methylpropylimidazole salts; pyridinium derivatives, such as N,N-dimethylpyridinium salts and N,N-methylpropylpyridinium salts; and aliphatic quaternary ammonium salts, such as trimethylpropylammonium salts, trimethylhexylammonium salts, and triethylhexylammonium salts. Furthermore, in consideration of stability in the atmosphere, it is preferable to use a fluorine-containing compound as the anionic component, such as BF4 - , CF3SO3 - , PF4 - , (CF3SO2)2N - , tetracyanoboron anion (B(CN)4 - ) etc.

[0175] As the electrolyte material, an ionic liquid containing any combination of cationic and anionic components is preferably used. The ionic liquid may be directly dissolved in a photopolymerizable monomer, oligomer, or liquid crystal material. If the ionic liquid has poor solubility, it may be dissolved in a small amount of solvent and the resulting solution may be mixed with the photopolymerizable monomer, oligomer, or liquid crystal material. Examples of suitable solvents include propylene carbonate, acetonitrile, γ-butyrolactone, ethylene carbonate, sulfolane, dioxolane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, 1,2-dimethoxyethane, 1,2-ethoxymethoxyethane, polyethylene glycol, alcohols, and mixtures thereof.

[0176] The electrolyte does not need to be a low-viscosity liquid, and can take various forms, such as a gel, a polymer cross-linked type, or a liquid crystal dispersion type. Forming the electrolyte into a gel or solid state offers advantages such as improved element strength and reliability. A preferred solidification method involves retaining the electrolyte and solvent in a polymer, as this provides high ionic conductivity and solid strength. Furthermore, a photocurable resin is preferred as the polymer, as this allows for the production of electrochromic elements at lower temperatures and in a shorter time than methods involving thermal polymerization or solvent evaporation to form thin films. The average thickness of the electrolyte layer is not particularly limited and can be selected appropriately depending on the purpose, but is preferably between 100 nm and 10 μm.

[0177] [Second Electrochromic Layer] The second electrochromic layer is laminated on the lower surface of the second electrode in one layer, but is not limited to this and may be laminated in multiple layers. Furthermore, the second electrochromic layer is laminated on the entire lower surface of the second electrode, but is not limited to this and may be laminated on only a part of the lower surface of the second electrode.

[0178] The second electrochromic layer can contain a second electrochromic compound represented by a compound (viologen compound) represented by the following general formula (I). The second electrochromic layer contains an electrochromic composite in which a conductive nanostructure or a semiconducting nanostructure (conductive or semiconducting nanostructure) contains the viologen compound represented by the following general formula (I). The viologen compound represented by the following general formula (I) can be bound to or adsorbed to the conductive or semiconducting nanostructure. When used in an electrochromic device, the electrochromic composite emits mainly blue light and further exhibits excellent image memory properties, i.e., excellent color image retention.

[0179] [ka]

[0180] In addition to the viologen compound represented by the general formula (I) above, the second electrochromic layer may also contain a phosphonic acid compound or a linear alkylphosphonic acid, such as those represented by the following general formula (II) described in JP-A-2017-111434, either alone or co-adsorbed with a viologen compound.

[0181] [ka]

[0182] -Viologen compounds- The viologen compound represented by the above general formula (I) will now be described.

[0183] In the general formula (I), R1 and R2 each represent a hydrogen atom, an aryl group having up to 14 carbon atoms, a heteroaryl group, a branched alkyl group having up to 10 carbon atoms, an alkenyl group, a cycloalkyl group, or a functional group capable of bonding to a hydroxyl group. n and m each represent 0 or an integer of 1 to 10. X - represents an ion that neutralizes the charge.

[0184] In a more preferred embodiment, either R1 or R2 is a functional group capable of bonding to a hydroxyl group. This allows for adsorption and immobilization on a transparent electrode (e.g., ITO). This is also advantageous when metal oxide support particles are provided on a transparent electrode, as this similarly allows for adsorption and immobilization on the transparent electrode. In an even more preferred embodiment, both R1 and R2 are functional groups capable of bonding to a hydroxyl group.

[0185] Examples of functional groups that can bond to a hydroxyl group include a phosphonic acid group, a phosphoric acid group, a carboxylic acid group, a sulfonyl group, a silyl group, a silanol group, etc. Among these, from the viewpoints of ease of synthesis, adsorption to support particles when metal oxide support particles are provided on a transparent electrode, and stability of the compound, the phosphonic acid group, the phosphoric acid group, and the carboxyl group are preferred, and the phosphonic acid group is more preferred.

[0186] Examples of the phosphonic acid group include a methylphosphonic acid group, an ethylphosphonic acid group, a propylphosphonic acid group, a hexylphosphonic acid group, an octylphosphonic acid group, a decylphosphonic acid group, a dodecylphosphonic acid group, an octadecylphosphonic acid group, a benzylphosphonic acid group, a phenylethylphosphonic acid group, a phenylpropylphosphonic acid group, and a biphenylphosphonic acid group.

[0187] Examples of the phosphate group include a methyl phosphate group, an ethyl phosphate group, a propyl phosphate group, a hexyl phosphate group, an octyl phosphate group, a decyl phosphate group, a dodecyl phosphate group, an octadecyl phosphate group, a benzyl phosphate group, a phenylethyl phosphate group, a phenylpropyl phosphate group, and a biphenyl phosphate group.

[0188] Examples of the carboxyl group include a methyl carboxylic acid group, an ethyl carboxylic acid group, a propyl carboxylic acid group, a hexyl carboxylic acid group, an octyl carboxylic acid group, a decyl carboxylic acid group, a dodecyl carboxylic acid group, an octadecyl carboxylic acid group, a benzyl carboxylic acid group, a phenylethyl carboxylic acid group, a phenylpropyl carboxylic acid group, a biphenyl carboxylic acid group, a 4-propylphenyl carboxylic acid group, and a 4-propylbiphenyl carboxylic acid group.

[0189] Examples of sulfonyl groups include methylsulfonyl, ethylsulfonyl, propylsulfonyl, hexylsulfonyl, octylsulfonyl, decylsulfonyl, dodecylsulfonyl, octadecylsulfonyl, benzylsulfonyl, phenylethylsulfonyl, phenylpropylsulfonyl, and biphenylsulfonyl groups.

[0190] Examples of the silyl group include a methylsilyl group, an ethylsilyl group, a propylsilyl group, a hexylsilyl group, an octylsilyl group, a decylsilyl group, a dodecylsilyl group, an octadecylsilyl group, a benzylsilyl group, a phenylethylsilyl group, a phenylpropylsilyl group, and a biphenylsilyl group.

[0191] Examples of silanol groups include methylsilanol groups, ethylsilanol groups, propylsilanol groups, hexylsilanol groups, octylsilanol groups, decylsilanol groups, dodecylsilanol groups, octadecylsilanol groups, benzylsilanol groups, phenylethylsilanol groups, phenylpropylsilanol groups, and biphenylsilanol groups.

[0192] In the above general formula (I), the charge-neutralizing ion X - Each of the ions represents a monovalent anion, and is not particularly limited as long as it forms a stable pair with the cation moiety. - For example, Br ions (Br - ), Cl ions (Cl - ), I ions (I - ), OTf (triflate) ion (OTf - ), ClO4 ion (ClO4 - ), PF6 ion (PF6 - ), BF4 ion (BF4 - ) is preferred.

[0193] The viologen compound is preferably a symmetrical system having an alkyl chain of a certain length, and in the above general formula (I), m and n are preferably both 4 to 10, and m and n are preferably the same integer.

[0194] Specific examples of the viologen compound include those shown below, but the viologen compound is not limited to these.

[0195] <Example Compound A> [ka]

[0196] <Example Compound B> [ka]

[0197] <Exemplary compound C>

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[0198] <Exemplary compound D>

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[0199] <Exemplary compound E>

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[0200] <Exemplary compound F>

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[0201] <Exemplary compound G>

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[0202] <Exemplary compound H>

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[0203] <Exemplary Compound I>

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[0204] <Exemplary Compound J>

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[0205] <Exemplary compound K>

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[0206] -Conductive and semiconducting nanostructures- Conductive or semiconducting nanostructures are described. The conductive or semiconducting nanostructures are preferably transparent.

[0207] At least one selected from R1 and R2 in the general formula (I) is a functional group capable of bonding to a hydroxyl group, and a phosphonic acid group, sulfonic acid group, phosphoric acid group, carboxyl group, etc. is used for bonding or adsorbing the viologen compound to the conductive or semiconducting nanostructure. In this case, the second electrochromic compound is easily composited with the nanostructure to form an electrochromic composite with excellent color image retention.

[0208] The viologen compound may contain a plurality of phosphonic acid groups, sulfonic acid groups, phosphoric acid groups, and carboxyl groups. Furthermore, when the viologen compound contains a silyl group, a silanol group, or the like, it is bonded to the nanostructure via a siloxane bond, which strengthens the bond, thereby enabling the production of a stable electrochromic composite. The siloxane bond refers to a chemical bond via a silicon atom and an oxygen atom.

[0209] The electrochromic composite may have a structure in which a viologen compound and a nanostructure are bonded via a siloxane bond, and there are no particular limitations on the bonding method or form.

[0210] The conductive or semiconducting nanostructure refers to a structure having nanoscale irregularities such as nanoparticles or nanoporous structures. As a material for constituting the conductive or semiconducting nanostructure, metal oxides are preferred in terms of transparency and conductivity.

[0211] Examples of metal oxides include those containing titanium oxide, zinc oxide, tin oxide, zirconium oxide, cerium oxide, yttrium oxide, boron oxide, magnesium oxide, strontium titanate, potassium titanate, barium titanate, calcium titanate, calcium oxide, ferrite, hafnium oxide, tungsten oxide, iron oxide, copper oxide, nickel oxide, cobalt oxide, barium oxide, strontium oxide, vanadium oxide, indium oxide, aluminosilicate, calcium phosphate, or aluminosilicate as a main component. These may be used alone or in combination of two or more. Among these, titanium oxide, zinc oxide, tin oxide, zirconium oxide, iron oxide, magnesium oxide, indium oxide, and tungsten oxide are preferred, with titanium oxide being more preferred, from the standpoint of electrical properties such as electrical conductivity and physical properties such as optical properties. When a metal oxide or a mixture of metal oxides is used, the color development / fading response speed is excellent.

[0212] The metal oxide preferably has the form of metal oxide fine particles with an average primary particle diameter of 30 nm or less. The smaller the average primary particle diameter, the more improved the light transmittance of the metal oxide, and the larger the surface area per unit volume of the electrochromic composite (hereinafter referred to as "specific surface area"). By having a large specific surface area, the second electrochromic compound can be more efficiently supported on the conductive or semiconductive nanostructure, allowing for a multicolor display with an excellent display contrast ratio for color development and fading. The specific surface area of ​​the electrochromic composite is not particularly limited and can be selected appropriately depending on the purpose, but for example, it is preferable that the specific surface area is 100 m 2 / g or more is preferable.

[0213] The average primary particle diameter of the metal oxide microparticles is determined by observing 100 randomly selected metal oxide microparticles under a transmission electron microscope (TEM), determining their projected areas, calculating the circle-equivalent diameter of the obtained area to determine the particle size, and averaging these values ​​to determine the average primary particle diameter.

[0214] Examples of methods for forming the second electrochromic layer include vacuum deposition, sputtering, ion plating, etc. In addition, as long as the material of the second electrochromic layer can be applied, various printing methods can be used, such as spin coating, casting, microgravure coating, gravure coating, bar coating, roll coating, wire bar coating, dip coating, slit coating, capillary coating, spray coating, nozzle coating, gravure printing, screen printing, flexographic printing, offset printing, reverse printing, and inkjet printing.

[0215] The average thickness of the second electrochromic layer is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 0.2 μm or more and 5.0 μm or less. An average thickness of 0.2 μm or more ensures color density, while an average thickness of 5.0 μm or less prevents increases in manufacturing costs and reduces the decrease in visibility due to coloring. The second electrochromic layer can be formed by vacuum film formation, but from the standpoint of productivity, it is preferable to apply the layer as a particle-dispersed paste.

[0216] [First support and second support] The first support and second support (support) have the function of supporting the first electrode, the first electrochromic layer, the second electrode, the second electrochromic layer, etc. As the support, any known organic or inorganic material can be used as is, as long as it is a transparent material that can support each layer.

[0217] The support may be, for example, a glass substrate such as alkali-free glass, borosilicate glass, float glass, or soda-lime glass. Alternatively, the support may be, for example, a resin substrate such as a polycarbonate resin, an acrylic resin, a polyethylene resin, a polyvinyl chloride resin, a polyester resin, an epoxy resin, a melamine resin, a phenolic resin, a polyurethane resin, or a polyimide resin. The surface of the support may be coated with a transparent insulating layer, a UV-cut layer, an anti-reflection layer, or the like to improve water vapor barrier properties, gas barrier properties, UV resistance, and visibility.

[0218] The planar shape of the support is not particularly limited and can be appropriately selected depending on the purpose, and may be, for example, rectangular or circular. The support may be a laminate of multiple supports, and for example, by using a structure in which the electrochromic element is sandwiched between two glass substrates, it is possible to improve the water vapor barrier property and gas barrier property.

[0219] [Other materials] The other members are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include an insulating porous layer, a deterioration prevention layer, and a protective layer.

[0220] -Insulating porous layer- The insulating porous layer serves to electrically insulate the first electrode from the second electrode and to retain the electrolyte. There are no particular limitations on the material for the insulating porous layer as long as it is porous, and it is preferable to use an organic material, an inorganic material, or a composite thereof that has high insulating properties and durability and excellent film-forming properties.

[0221] Examples of methods for forming an insulating porous layer include a sintering method (using the pores formed between particles by partially fusing polymer fine particles or inorganic particles with the addition of a binder or the like), an extraction method (forming a constituent layer using organic or inorganic substances that are soluble in a solvent and a binder or the like that is not soluble in the solvent, and then dissolving the organic or inorganic substances in a solvent to obtain pores), a foaming method, a phase inversion method in which a mixture of polymers is phase-separated by manipulating a good solvent and a poor solvent, and a radiation irradiation method in which various types of radiation are radiated to form pores.

[0222] -Deterioration prevention layer- The role of the anti-degradation layer is to undergo a reverse chemical reaction with the first and second electrochromic layers, balance the charge, and prevent the first and second electrodes from corroding or deteriorating due to an irreversible redox reaction. Note that the reverse reaction includes not only the case where the anti-degradation layer undergoes redox, but also its function as a capacitor.

[0223] The material for the anti-degradation layer is not particularly limited as long as it serves to prevent corrosion of the first electrode and the second electrode due to irreversible oxidation-reduction reactions, and can be appropriately selected depending on the purpose. Examples of materials that can be used for the anti-degradation layer include antimony tin oxide, nickel oxide, titanium oxide, zinc oxide, tin oxide, and conductive or semiconducting metal oxides containing a combination of these. The anti-degradation layer can be composed of a porous thin film that does not inhibit the injection of electrolyte. For example, by immobilizing conductive or semiconducting metal oxide particles such as antimony tin oxide, nickel oxide, titanium oxide, zinc oxide, or tin oxide on the second electrode using a binder such as an acrylic, alkyd, isocyanate, urethane, epoxy, or phenol, a suitable porous thin film that is permeable to the electrolyte and functions as an anti-degradation layer can be obtained.

[0224] -Protective layer- The protective layer is used to protect the electrochromic element from external stress and chemicals used in the cleaning process, to prevent electrolyte leakage, and to prevent the intrusion of substances unnecessary for stable operation of the electrochromic element, such as moisture and oxygen in the atmosphere.

[0225] The material of the protective layer may be, for example, an ultraviolet-curable or thermosetting resin, and specific examples include acrylic, urethane, and epoxy resins.

[0226] The average thickness of the protective layer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 μm to 200 μm.

[0227] [Method for manufacturing an electrochromic device according to the first embodiment] An example of a method for manufacturing the electrochromic element according to the first embodiment will be described.

[0228] First, a display electrode 12 is formed on a first support 11. Then, a coating liquid (electrolyte liquid) containing a first electrochromic composition including the electrochromic compound of the present invention and other radically polymerizable compounds is applied onto the display electrode 12. This produces a first laminate in which the display electrode 12 and the first electrochromic layer 13 are formed in this order on the first support 11.

[0229] The electrochromic compound and other radically polymerizable compounds of the present invention may be the same as those described in the electrochromic element of the first embodiment.

[0230] The coating solution is diluted with a solvent as needed and then applied. The solvent is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include alcohol-based solvents such as methanol, ethanol, propanol, and butanol; ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester-based solvents such as ethyl acetate and butyl acetate; ether-based solvents such as tetrahydrofuran, dioxane, and propyl ether; halogen-based solvents such as dichloromethane, dichloroethane, trichloroethane, and chlorobenzene; aromatic solvents such as benzene, toluene, and xylene; and cellosolve-based solvents such as methyl cellosolve, ethyl cellosolve, and cellosolve acetate. These may be used alone or in combination of two or more.

[0231] The dilution rate with the solvent varies depending on the solubility of the first electrochromic composition, the coating method, the thickness of the first electrochromic layer, and the like, and can be selected appropriately.

[0232] Examples of the coating method include dip coating, spray coating, bead coating, and ring coating.

[0233] The method for producing an electrochromic element according to the first embodiment may also include a step of applying external energy to the applied first electrochromic composition to polymerize and crosslink it (polymerization and crosslinking step).

[0234] In the polymerization and crosslinking step, the first electrochromic composition is applied to the first electrode, and then external energy is applied to harden the composition to form a first electrochromic layer. Examples of external energy include heat, light, and radiation. Heat energy can be applied by heating the coated surface or the support using gases such as air and nitrogen, steam, various heat media, infrared rays, or electromagnetic waves.

[0235] The heating temperature is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 60°C to 170°C. Regarding light energy, UV irradiation light sources such as high-pressure mercury lamps and metal halide lamps, which mainly emit ultraviolet (UV) light, can be used, but a visible light source can also be selected to match the absorption wavelength of the radical polymerizable ingredient or photopolymerization initiator. The UV irradiation light intensity is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 5 mW / cm. 2 ~15,000mW / cm 2 is preferred.

[0236] Next, a counter electrode 16 is formed on a second support 17. After that, a coating liquid containing a second electrochromic composition and an electrochromic composite including a conductive or semiconducting nanostructure is applied onto the counter electrode 16. In this way, a second laminate is produced in which the counter electrode 16 and the second electrochromic layer 15 are formed in this order on the second support 17.

[0237] The second electrochromic composition and the conductive or semiconductive nanostructure contained in the electrochromic composite may be the same as those described in the electrochromic element of the first embodiment.

[0238] Next, an electrolyte solution is applied between the first laminate and the second laminate, and the first laminate and the second laminate are provided with the electrolyte layer 14A interposed therebetween. This completes the manufacture of the electrochromic device 10A according to the first embodiment. If the electrolyte constituting the electrolyte layer 14A can be cured by light or heat, the first laminate and the second laminate are bonded together with the electrolyte interposed therebetween and then cured.

[0239] The method for manufacturing the electrochromic element according to the first embodiment may further include other steps as necessary.

[0240] For example, when the electrochromic device 10A according to the first embodiment includes an insulating porous layer, the process may include a step of forming the insulating porous layer on the first electrochromic layer 13. The insulating porous layer may also be formed on the lower surface of the second electrochromic layer 15, or may be mixed with the electrolyte that constitutes the electrolyte layer 14A.

[0241] Additionally, if the electrochromic element 10A according to the first embodiment includes an anti-deterioration layer or a protective layer, a step of forming these layers within the electrochromic element 10A according to the first embodiment may be included.

[0242] [Electrochromic element according to the second embodiment] An electrochromic element according to a second embodiment will now be described. The electrochromic element 10B according to the second embodiment does not have the first electrochromic layer 13 and the second electrochromic layer 15 of the electrochromic element 10A according to the first embodiment shown in FIG. 1. The electrochromic element 10B according to the second embodiment uses an electrolyte layer containing the electrochromic compound of the present invention or the electrochromic composition of the present invention instead of the electrolyte layer 14A of the electrochromic element 10A according to the first embodiment.

[0243] FIG. 2 is a diagram showing an example of the configuration of an electrochromic element according to a second embodiment. The electrochromic element 10B according to the second embodiment in FIG. 2 has a first support 11, a display electrode 12, an electrolyte layer 14B, a counter electrode 16, and a second support 17. These components are stacked in this order from the first support 11 side. The electrolyte layer 14B contains the electrochromic compound of the present invention or the electrochromic composition of the present invention and an electrolyte. Each of the components constituting the electrochromic element 10B according to the second embodiment is the same as that of the electrochromic element 10A according to the first embodiment, and therefore detailed description thereof will be omitted.

[0244] [Method for manufacturing an electrochromic device according to the second embodiment] An example of a method for manufacturing an electrochromic element according to the second embodiment will be described. The method for manufacturing an electrochromic element 10B according to the second embodiment does not include the step of providing the first electrochromic layer 13 and the second electrochromic layer 15 of the electrochromic element 10A according to the first embodiment shown in FIG. 1. The method for manufacturing an electrochromic element 10B according to the second embodiment includes the step of forming an electrolyte layer 14B containing the electrochromic compound or the electrochromic composition of the present invention, instead of the electrolyte layer 14A.

[0245] That is, the display electrodes 12 are formed on the first support 11. The counter electrodes 16 are formed on the second support 17.

[0246] Next, an electrolyte solution containing the electrochromic compound of the present invention or the electrochromic composition of the present invention and an electrolyte is prepared. Thereafter, the electrolyte solution is applied between the display electrode 12 and the counter electrode 16, and the display electrode 12 and the counter electrode 16 are provided with the electrolyte layer 14B interposed therebetween. This completes the production of the electrochromic element 10B according to the second embodiment.

[0247] The electrochromic elements according to the first and second embodiments have excellent light durability and repetitive durability. Therefore, the electrochromic elements according to the above embodiments can be suitably used in, for example, electrochromic displays, large display boards such as stock price displays, and dimming elements such as anti-glare mirrors and dimming glass. Furthermore, the electrochromic elements according to the above embodiments can be suitably used in low-voltage drive elements such as touch panel key switches, optical switches, optical memories, electronic paper, electronic albums, and the like.

[0248] Although the embodiments have been described above, they are presented as examples and the present invention is not limited to the above embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the inventions and their equivalents as set forth in the claims. [Example]

[0249] Examples of the present invention will be described below, but the present invention is not limited to these examples in any way.

[0250] Example 1 <Synthesis of electrochromic compound 1> [ka]

[0251] <Synthesis of Compound 1-1> p-Bromophenol (TCI, 18.4 g, 106 mmol), acetone (300 mL), potassium carbonate (Kanto Chemical, fine powder, 2.4 eq to phenol, 35.2 g, 255 mmol), and 1-bromo-3-chloropropane (TCI, 2 eq to phenol, 33.4 g, 212 mmol) were placed in a recovery flask and stirred at an internal temperature of 40°C for 15 hours. The organic layer was concentrated, and the residue was purified by silica gel column chromatography (hexane / ethyl acetate) to obtain compound 1-1 as a colorless solid (yield: 24.4 g, 92%).

[0252] 1 H NMR(500MHz, CDCl3) δ7.40-7.37(m,2H),6.98-6.94(m,2H),6.91-6.88(m,2H),6.83-6.80(m,2H), 4.10(t,J=6.0Hz,2H),3.76(t,J=6.5Hz,2H),2.26-2.22(quint,J=6.5Hz,2H)

[0253] MS (ASAP): 247.955 (measured value), 247.960 (theoretical value)

[0254] <Synthesis of Compound 1-2> A four-neck flask was charged with 4-tert-butylaniline (1.56 g, 10.5 mmol), palladium acetate (TCI, 88 mg, 0.4 mmol), tri-tert-butylphosphonium tetrafluoroborate (TCI, 348 mg, 1.2 mmol), compound 1-1 (10 mmol, 2.5 g), and sodium tert-butoxide (TCI, 1.82 g, 18.0 mmol). The atmosphere was purged with argon gas, and then dehydrated toluene (Kanto Chemical, 30 mL) that had been degassed with argon gas was added. The solution was heated at 110 °C for 4 hours under an argon stream. The solution was cooled to room temperature and filtered through Celite. The Celite was washed with toluene, and the combined filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (hexane / toluene) and dried under reduced pressure to obtain compound 1-2 as a brown liquid (yield 2.36 g, 74%).

[0255] MS (ASAP): 317.148 (measured value), 317.155 (theoretical value)

[0256] <Synthesis of Compounds 1-3> A four-neck flask was charged with 4,4'-dibromophenyl (TCI, 1.13 g, 3.6 mmol), compound 1-2 (2.36 g, 7.42 mmol), palladium acetate (TCI, 18.0 mg, 0.08 mmol), and tri-tert-butylphosphonium tetrafluoroborate (TCI, 69.6 mg, 0.24 mmol). The atmosphere was replaced with argon gas, and then xylene (30 mL) was added. Argon gas was then bubbled through the flask for 10 minutes. The solution was heated to 70 °C, and sodium tert-butoxide (TCI, 1.15 g, 12.0 mmol) was added. The solution was heated at 110 °C for 3 hours. The solution was filtered through Celite, the Celite was washed with toluene, and the combined filtrate was concentrated to give a brown solid. Methanol was added and the solid was dispersed using an ultrasonic cleaner. The solid was collected by filtration to give compound 1-3 as a colorless solid (yield: 2.77 g, 98%).

[0257] 1 H NMR(500MHz,acetone-d6) δ7.47-7.51(m,4H),7.32-7.35(m,4H),7.06-7.09(m,4H),6.96-7.01(m,12H) ,4.15(t,J=6.0Hz,4H),3.82(t,J=6.5Hz,4H),2.23-2.27(m,4H),1.31(s,18H)

[0258] MS (ASAP): 784.350 (measured value), 784.356 (theoretical value)

[0259] <Synthesis of electrochromic compound 1> Compound 1-3 (2.75 g, 3.5 mmol), acrylic acid (TCI, 1.51 g, 21 mmol), potassium carbonate (Kanto Chemical, fine powder, 3.7 g, 25.2 mmol), dehydrated dimethylformamide (60 mL), and 2,6-di-tert-butylcresol (2 crystals) were placed in a four-neck flask and heated at 85°C for 8.5 hours. The solution was cooled to room temperature, and water and ethyl acetate were added to separate the organic layer. The aqueous layer was extracted four times with ethyl acetate, and the combined organic layer was washed three times with water, followed by saturated brine, and dried over anhydrous sodium sulfate. The drying agent was filtered off, and the filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (toluene / ethyl acetate). 2,6-di-tert-butylcresol (1.55 mg) was added to the eluate, and the mixture was concentrated under reduced pressure to obtain electrochromic compound 1 as a pale yellow amorphous solid (yield: 2.29 g, yield: 76%, BHT content: 677 ppm).

[0260] 1 H NMR(500MHz, CDCl3) δ:7.44(d,J=9.0Hz,4H),7.30(d,J=8.5Hz,4H),7.02(d,J=9.0Hz,4H),6.93 (dd,J=0.3Hz,9.0Hz,8H),6.89(d,J=9.0Hz,4H),6.34(dd,J1=1.5Hz,J2=17. 0Hz,2H),6.22-6.16(m,2H),5.95(dd,J1=1.5Hz,J2=10.0Hz,2H),4.27(t,J =6.5Hz,4H),4.04(t,J=6.0Hz,4H),2.08(quint,J=6.5Hz,4H),1.26(s,18H)

[0261] MS(ASAP): 856.440 (measured value), 856.445 (theoretical value)

[0262] Example 2 <Synthesis of electrochromic compound 2> [ka]

[0263] <Synthesis of Compound 2-1> A recovery flask was charged with 4-bromo-4'-hydroxydiphenyl ether (Aldrich, 10.3 g, 38.7 mmol), acetone (100 mL), potassium carbonate (Kanto Chemical, fine powder, 3 eq to phenol, 16.0 g, 116 mmol), and 1-bromo-3-chloropropane (TCI, 2.5 eq to phenol, 15.2 g, 96.8 mmol), and the mixture was heated and stirred under reflux for 6 hours. After cooling to room temperature, the precipitate was filtered and washed with ethyl acetate. The combined organic layer was concentrated, and the residue (20 g) was purified by silica gel column chromatography (hexane / ethyl acetate) to obtain compound 2-1 as a pale yellow solid (yield: 12.6 g, 95%).

[0264] 1 H NMR(500MHz, CDCl3) δ7.40-7.37(m,2H),6.98-6.94(m,2H),6.91-6.88(m,2H),6.83-6.80(m,2H), 4.10(t,J=6.0Hz,2H),3.76(t,J=6.5Hz,2H),2.26-2.22(quint,J=6.5Hz,2H)

[0265] MS (ASAP): 339.981 (measured value), 339.987 (theoretical value)

[0266] <Synthesis of Compound 2-2> Palladium acetate (TCI, 121 mg, 0.55 mmol), tri-tert-butylphosphonium tetrafluoroborate (TCI, 480 mg, 1.66 mmol), compound 2-1 (18.4 mmol, 6.29 g), dehydrated toluene (Kanto Chemical, 65 mL) degassed with argon gas, and sodium tert-butoxide (TCI, 2.57 g, 27.6 mmol) were placed in a four-neck flask under an argon stream and heated at 80°C for 10 minutes. Then, 4-tert-butylaniline (3.55 g, 23.9 mmol) was added. The solution was heated at 115°C (bath temperature) for 2.5 hours. The solution was cooled to room temperature and filtered through Celite. The Celite was washed with toluene, and the combined filtrate was concentrated under reduced pressure. The resulting residue (10 g) was purified by silica gel column chromatography (hexane / toluene = 7 / 3 → 3 / 7 (v / v), gradient) and dried under reduced pressure to obtain compound 2-2 as a brown liquid (yield 5.9 g, 78%).

[0267] MS(ASAP): 409.172 (measured value), 409.181 (theoretical value)

[0268] <Synthesis of Compound 2-3> A four-neck flask was charged with 4,4'-dibromophenyl (TCI, 2.15 g, 6.9 mmol), compound 2-2 (5.8 g, 14.15 mmol), palladium acetate (TCI, 31 mg, 0.138 mmol), tri-tert-butylphosphonium tetrafluoroborate (TCI, 120 mg, 0.414 mmol), and toluene (50 mL) degassed with argon gas. Argon gas was bubbled through the solution for 10 minutes. The solution was heated to 80°C, and sodium tert-butoxide (TCI, 1.99 g, 20.7 mmol) was added. The solution was heated at 115°C for 7 hours. The solution was cooled to approximately 70°C and filtered through a Celite pad while hot. The Celite was washed with toluene, and the combined filtrates were concentrated, purified by silica gel column chromatography (hexane / toluene), and dried under reduced pressure to obtain compound 2-3 as a colorless amorphous solid (yield: 5.73 g, 86%).

[0269] 1 H NMR(500MHz,C6D6) δ7.43-7.40(m,4H),7.23-7.16(m,12H),7.10-7.07(m,4H),6.99-6.90(m,8H),3.55(t,J=6.0Hz,4H),1.69(quint,J=6.0Hz,4H),1.24(s,18H)

[0270] MS (ASAP): 968.400 (measured value), 968.409 (theoretical value)

[0271] <Synthesis of electrochromic compound 2> Compound 2-3 (5.64 g, 5.8 mmol), acrylic acid (TCI, 2.51 g, 34.9 mmol), potassium carbonate (Kanto Chemical, fine powder, 6.2 g, 41.9 mmol), dehydrated dimethylformamide (130 mL), and 2,6-di-tert-butylcresol (3 crystals) were placed in a four-neck flask and heated at 85 °C for 12.5 hours. The solution was cooled to room temperature, and water and ethyl acetate were added to separate the organic layer. The aqueous layer was extracted four times with ethyl acetate. The combined organic layer was washed four times with water, followed by saturated brine, and then dried over anhydrous sodium sulfate. The drying agent was filtered off, and the filtrate was concentrated under reduced pressure. The resulting residue (8.2 g) was purified by silica gel column chromatography (toluene / ethyl acetate (10 / 0)). 2,6-di-tert-butylcresol (3.2 mg) was added to the eluate, and the mixture was concentrated under reduced pressure to obtain electrochemical compound 2 as a colorless amorphous solid (yield: 5.37 g, yield: 88.7%, BHT content: 600 ppm).

[0272] 1H NMR(500MHz,C6D6) δ:7.43(dd,J1=7.0Hz,J2=2.0Hz,4H),7.23-7.17(m,12H),7.08(d,J1=7.0Hz,J2=2.0Hz,4H),6.97( dd,J1=6.5Hz,J2=2.0Hz,4H),6.92(dd,J1=6.5Hz,J2=2.0Hz,4H),6.66(d,J1=6.8Hz,J2=2.0Hz,4H) ,6.28(d,J1=17.3Hz,J2=1.43Hz,2H),5.95(d,J1=17.5Hz,J2=10.3Hz,2H),5.23(d,J1=10.3Hz,J2= 1.43Hz,2H),4.16(t,J=6.3Hz,4H),3.53(t,J=6.3Hz,4H),1.74(quint,J=6.3Hz,4H),1.24(s,18H)

[0273] MS(ASAP): 1040.486 (measured value), 1040.498 (theoretical value)

[0274] (Example 1-1) <Fabrication of the first electrochromic element> An example of the preparation of the electrochromic device of Example 1-1 is shown below.

[0275] - Formation of a first electrochromic layer on a first electrode - To form a first electrochromic layer on the first electrode, a first electrochromic composition having the composition shown below was prepared. [composition] First electrochromic compound (exemplified compound 1): 50 parts by mass IRGACURE 184 (BASF Japan Ltd.): 5 parts by mass Polyethylene glycol having a diacryloxy group (PEG400DA, manufactured by Nippon Kayaku Co., Ltd.): 50 parts by mass Methyl ethyl ketone: 900 parts by weight

[0276] The resulting first electrochromic composition was then applied by spin coating to an ITO glass substrate (40 mm × 40 mm, 0.7 mm thick, ITO film thickness: approximately 100 nm) serving as a first electrode. The resulting coating film was irradiated with UV light at 10 mW for 60 seconds using a UV irradiation device (USHIO INC., SPOT CURE), and then annealed at 60°C for 10 minutes to form a crosslinked first electrochromic layer with an average thickness of 400 μm.

[0277] - Formation of a degradation prevention layer on the second electrode - Next, a titanium oxide nanoparticle dispersion (product name: SP210, manufactured by Showa Titanium Co., Ltd., average particle diameter: approximately 20 nm) was spin-coated onto an ITO glass substrate (40 mm × 40 mm, thickness: 0.7 mm, ITO film thickness: approximately 100 nm) serving as a second electrode to form an anti-degradation layer. This was then annealed at 120°C for 15 minutes to form a nanostructured semiconductor material consisting of a titanium oxide particle film with a thickness of 1.0 μm.

[0278] - Formation of a second electrochromic layer on a second electrode - To form a second electrochromic layer on the second electrode, a second electrochromic composition having the composition shown below was prepared. [composition] Second electrochromic compound (exemplified compound A): 20 parts by mass Tetrafluoropropanol: 980 parts by mass

[0279] The resulting second electrochromic composition was applied by spin coating to the nanostructured semiconductor material consisting of a titanium oxide particle film formed on the second electrode, and then the unadsorbed compound was washed away with methanol to form a second electrochromic layer.

[0280] -Electrolyte liquid filling- An electrolyte solution having the following composition was prepared. [composition] IRGACURE 184 (BASF Japan Ltd.): 5 parts by mass PEG400DA (manufactured by Nippon Kayaku Co., Ltd.): 100 parts by weight 1-Ethyl-3-methylimidazolium tetracyanoborate (Merck): 50 parts by mass

[0281] 30 mg of the obtained electrolyte solution was measured with a micropipette and dropped onto an ITO glass substrate serving as a second electrode having an anti-degradation layer and a second electrochromic layer. An ITO glass substrate serving as a first electrode having a crosslinked first electrochromic layer was bonded onto the second electrode so that the electrode lead-out portion was present, producing a bonded element. The resulting bonded element was irradiated with UV (wavelength 250 nm) at 10 mW for 60 seconds using a UV irradiation device (USHIO INC., SPOT CURE). Thus, the electrochromic element of Example 1-1 was produced.

[0282] <Color development / decolorization drive> The color development and decolorization of the electrochromic element of Example 1-1 was confirmed. A voltage of -2V was applied for 5 seconds between the lead portion of the first electrode and the lead portion of the second electrode. As a result, color development due to the first electrochromic compound of the first electrochromic layer was confirmed in the overlapping portion of the first electrode layer and the second electrode layer. Color development due to the second electrochromic compound of the second electrochromic layer was also confirmed. Next, a voltage of +2V was applied for 5 seconds between the lead portion of the first electrode and the lead portion of the second electrode, and it was confirmed that the overlapping portion of the first electrode layer and the second electrode layer decolorized and became transparent.

[0283] FIG. 3 shows the UV-visible absorption spectrum of the electrochromic device of Example 1-1 when it develops color. The absorption spectrum in FIG. 3 is the UV-visible absorption spectrum obtained by subtracting the UV-visible absorption spectrum of the second electrochromic compound when it develops color and the spectra of the first electrochromic compound and the second electrochromic compound when they are bleached from the UV-visible absorption spectrum of electrochromic compound 1-1 of the electrochromic device of Example 1-1 when it develops color. That is, the absorption spectrum in FIG. 3 shows only the UV-visible absorption spectrum of the first electrochromic compound (exemplary compound 1) when it develops color. Note that FIG. 3 shows the absorption spectrum in the wavelength range of 380 nm to 780 nm. As shown in FIG. 3, it was confirmed by visual observation that both the first electrochromic compound and the second electrochromic compound developed orange to brown colors.

[0284] (Examples 1-2 to 1-10) Electrochromic devices were fabricated in the same manner as in Example 1-1, except that the above-mentioned exemplary compound 1 used as the first electrochromic compound in Example 1-1 was replaced with the above-mentioned exemplary compounds 2 to 10. It was confirmed that the electrochromic devices of Examples 1-2 to 1-10 also exhibited ultraviolet-visible absorption spectra similar to those of the electrochromic device of Example 1-1. Figure 4 also shows the visible-ultraviolet absorption spectrum of the second electrochromic compound in Example 1-2 during color development. Similar to exemplary compound 1, an orange color was exhibited.

[0285] (Comparative Examples 1-1 to 1-6) Electrochromic devices were produced in the same manner as in Example 1-1, except that Exemplified Compound 1 used as the first electrochromic compound in Example 1-1 was changed to the following Comparative Compounds 1 to 6. It was confirmed that the electrochromic devices of Comparative Examples 1-1 to 1-6 also obtained ultraviolet-visible absorption spectra similar to those of the electrochromic device of Example 1-1.

[0286] <Comparative compound 1> [ka]

[0287] <Comparative compound 2> [ka]

[0288] <Comparative compound 3> [ka]

[0289] <Comparative compound 4> [ka]

[0290] <Comparative compound 5> [ka]

[0291] <Comparative compound 6> [ka]

[0292] Next, Table 1 shows the types and application positions of the electrochromic compounds used in Examples 1-1 to 1-10 and Comparative Examples 1-1 to 1-6.

[0293] <Evaluation> Using each of the prepared electrochromic devices, a cycle test, a continuous color development test, a light durability test, and a color test were carried out. The results are shown in Table 1.

[0294] [Test 1-1: Repeated durability test] For each of the electrochromic elements fabricated in Examples and Comparative Examples, a voltage of 2 V was applied between the lead portion of the first electrode and the lead portion of the second electrode for 5 seconds, followed by a voltage of -2 V for 5 seconds, which was counted as one color-developing / discharging driving operation. This color-developing / discharging driving operation was repeated 10,000 times. The absorption maximum in the visible region (380 nm to 780 nm) at this time was defined as λmax (490 nm in the case of Example 1). The change in absorbance at this time was measured using a spectrometer (USB4000, manufactured by Ocean Optics) and evaluated according to the following criteria. [Evaluation criteria] ○: When the absorbance of λmax is 95% or more compared to the initial state △: When the absorbance at λmax is 90% or more but less than 95% of the initial state ×: When the absorbance at λmax is less than 90% of the initial value

[0295] [Test 1-2: Continuous color development test] For each of the electrochromic devices prepared in Examples and Comparative Examples, a voltage of 1.6 V was applied between the first and second electrodes, and the color-developed state was maintained for 48 hours. The absorbance in the visible region (380-780 nm) before and after the voltage application was measured using a spectrometer (USB4000, manufactured by Ocean Optics), and the yellow index (YI) was calculated. The difference between the YI before and after the voltage application was taken as ΔYI, and the results were evaluated according to the following criteria. [Evaluation criteria] ○: ΔYI is less than 0.5 △: ΔYI is 0.5 or more and less than 3 ×: ΔYI is 3 or more

[0296] [Test 1-3: Light durability test] For each of the electrochromic elements fabricated in Examples and Comparative Examples, a voltage of 1.6 V was applied between the first and second electrodes. While maintaining the color-developed state of the electrochromic element, it was irradiated with artificial sunlight (product name: SOLAX XC-100W, manufactured by Seric Co., Ltd., 150,000 lux) through a UV-cut filter (product name: Lumicool 1501UH, manufactured by Lintec Corporation) for 48 hours. The electrochromic element was then irradiated with deuterium tungsten halogen light (product name: DH-2000, manufactured by Ocean Optics Inc.). The transmittance in the visible region (380 nm to 780 nm) before and after irradiation was measured using a spectrometer (USB4000, manufactured by Ocean Optics Inc.). The yellow index (YI) was calculated, and the difference between the YI values ​​before and after irradiation was defined as ΔYI. The evaluation was based on the following criteria. [Evaluation criteria] ○: When ΔYI is less than 5 △: When ΔYI is 5 or more and less than 10 ×: ΔYI is 10 or more

[0297] [Table 1]

[0298] From the results in Table 1, it was confirmed that the electrochromic elements of Examples 1-1 to 1-10 satisfied all of the requirements for repeated operation durability, continuous color development, and light durability, and were particularly excellent in continuous operation stability and light durability. In contrast, it was confirmed that the electrochromic elements of Comparative Examples 1-1 to 1-6 did not satisfy all of the requirements for repeated operation durability, continuous color development, and light durability. Therefore, it can be said that the electrochromic composition of the present invention contributes to improving the continuous driving stability and light durability of electrochromic devices compared to conventional materials.

[0299] Example 2-1 <Fabrication of the second electrochromic element> An example of the preparation of the electrochromic device of Example 2-1 will be described below.

[0300] -Formation of spacers on the first electrode- An isopropanol solution of gap control particles (average particle size 80 μm, product name Micropearl GS, manufactured by Sekisui Chemical Co., Ltd.) was applied to an ITO glass substrate (40 mm × 40 mm, thickness 0.7 mm, ITO film thickness: approximately 100 nm) serving as a first electrode, and then dried at 80°C for 3 minutes.

[0301] - Formation of a degradation prevention layer on the second electrode - Next, a titanium oxide nanoparticle dispersion (product name: SP210, manufactured by Showa Titanium Co., Ltd., average particle diameter: approximately 20 nm) was spin-coated onto an ITO glass substrate (40 mm × 40 mm, thickness: 0.7 mm, ITO film thickness: approximately 100 nm) serving as a second electrode to form an anti-degradation layer. This was then annealed at 120°C for 15 minutes to form a nanostructured semiconductor material consisting of a titanium oxide particle film with a thickness of 1.0 μm.

[0302] -Board bonding- The ITO substrate serving as the first electrode and the ITO substrate serving as the second electrode were bonded together, with the electrode surfaces facing each other and offset by 5 mm to form the electrode lead-out area. A sealant (TB3050B, manufactured by ThreeBond Co., Ltd.) was then applied to the end surfaces, excluding the two injection holes, and the resulting bonded element was irradiated with UV (wavelength 250 nm) at 10 mW for 60 seconds using a UV irradiation device (SPOT CURE, manufactured by Ushio Inc.).

[0303] -Electrolyte liquid filling- An electrolyte solution having the following composition was prepared. [composition] Electrochromic compound 2-1 (exemplified compound M1): 50 parts by mass 1-Ethyl-3-methylimidazolium bisfluorosulfonylimide (EMIM-FSI) (manufactured by Merck): 100 parts by mass N-methylpyrrolidone (NMP): 600 parts by weight

[0304] 30 mg of the obtained electrolyte solution was measured with a micropipette and injected through the injection hole of the cell. The injection hole was sealed with a sealant, and similarly, UV (wavelength 250 nm) was irradiated at 10 mW for 60 seconds using a UV irradiation device (USHIO INC., SPOT CURE). In this way, an electrochromic element of Example 2-1 as shown in FIG. 2 was produced.

[0305] <Color development / decolorization drive> The color development and fading of the electrochromic element of Example 2-1 prepared was confirmed in the same manner as the electrochromic element of Example 1-1. As a result, when a voltage of 2 V was applied for 5 seconds between the lead portion of the first electrode and the lead portion of the second electrode, color development (orange) due to electrochromic compound 2 of the electrochromic layer was confirmed in the overlapping portion of the first electrode and the second electrode. Furthermore, when a voltage of -2 V was applied for 5 seconds between the lead portion of the first electrode and the lead portion of the second electrode, it was confirmed that the overlapping portion of the first electrode and the second electrode was decolorized and became transparent.

[0306] (Examples 2-2 to 2-5) An electrochromic element was produced in the same manner as in Example 2-1, except that the exemplary compound M1 used as the electrochromic compound 2-1 in Example 2-1 was changed to any one of the exemplary compounds M2 to M5.

[0307] (Comparative Examples 2-1 to 2-6) Electrochromic devices were produced in the same manner as in Example 1, except that the exemplary compound M1 used as the electrochromic compound 2-1 in Example 2-1 was changed to the comparative compounds m1 to m6 shown below. Note that it was confirmed that the electrochromic devices of Comparative Examples 2-1 to 2-6 also exhibited color development derived from the electrochromic compound 2-1, similar to the electrochromic device of Example 2-1.

[0308] <Comparative compound m1> [ka]

[0309] <Comparative compound m2> [ka]

[0310] <Comparative compound m3> [ka]

[0311] <Comparative compound m4> [ka]

[0312] <Comparative compound m5> [ka]

[0313] <Comparative compound m6> [ka]

[0314] <Evaluation> Using each of the electrochromic devices thus fabricated, a continuous color development test, a light durability test, a color test, and a degradation analysis were carried out. The results are shown in Table 2.

[0315] [Test 2-1: Repeated durability test] For each of the electrochromic elements fabricated in Examples and Comparative Examples, a voltage of 2 V was applied between the lead portion of the first electrode and the lead portion of the second electrode for 5 seconds, followed by a voltage of -2 V for 5 seconds, which was counted as one color-developing / decoloring driving operation. This color-developing / decoloring driving operation was repeated 10,000 times. The absorption maximum in the visible region (380 nm to 780 nm) at this time was defined as λmax (490 nm in the case of Example 1). The change in absorbance at this time was measured using a spectrometer (USB4000, manufactured by Ocean Optics) and evaluated according to the following criteria. [Evaluation criteria] ○: When the absorbance of λmax is 95% or more compared to the initial state △: When the absorbance at λmax is 90% or more but less than 95% of the initial state ×: When the absorbance at λmax is less than 90% of the initial value

[0316] [Test 2-2: Continuous color development test] For each of the electrochromic devices fabricated in Examples and Comparative Examples, a voltage of 1.6 V was applied between the first and second electrodes, and the color-developed state was maintained for 48 hours. The absorbance in the visible region (380 nm to 780 nm) before and after the voltage application was measured using a spectrometer (USB4000, manufactured by Ocean Optics), and the yellow index (YI) was calculated. The difference between the YI before and after the voltage application was taken as ΔYI, and the results were evaluated according to the following criteria. [Evaluation criteria] ○: ΔYI is less than 0.5 △: ΔYI is 0.5 or more and less than 3 ×: ΔYI is 3 or more

[0317] [Test 2-3: Light durability test] For each of the electrochromic elements fabricated in Examples and Comparative Examples, a voltage of 1.6 V was applied between the first and second electrodes. While maintaining the color-developed state of the electrochromic element, it was irradiated with artificial sunlight (product name: SOLAX XC-100W, manufactured by Seric Co., Ltd., 150,000 lux) through a UV-cut filter (product name: Lumicool 1501UH, manufactured by Lintec Corporation) for 48 hours. The electrochromic element was then irradiated with deuterium tungsten halogen light (product name: DH-2000, manufactured by Ocean Optics Inc.). The transmittance in the visible region (380 nm to 780 nm) before and after irradiation was measured using a spectrometer (USB4000, manufactured by Ocean Optics Inc.). The yellow index (YI) was calculated, and the difference between the YI values ​​before and after irradiation was defined as ΔYI. The evaluation was based on the following criteria. [Evaluation criteria] ○: When ΔYI is less than 5 △: When ΔYI is 5 or more and less than 10 ×: ΔYI is 10 or more

[0318] [Table 2] From the results in Table 2, it was confirmed that the electrochromic elements of Examples 2-1 to 2-5 satisfied both the continuous color development and light durability and were excellent in continuous driving stability and light durability. In contrast, it was confirmed that the electrochromic elements of Comparative Examples 2-1 to 2-6 were insufficient in either the continuous color development or light durability. Therefore, it can be said that the electrochromic compound 2-1 of the present invention contributes to improving the continuous driving stability and light durability of the electrochromic device.

[0319] Example 3-1 <Fabrication of the third electrochromic element> In Example 1-1, an electrochromic element was prepared in the same manner as in Example 1-1, except that the first electrochromic composition used was a first electrochromic compound obtained by mixing equal parts (50 parts by mass) of exemplary compound 1 and exemplary compound TPA1.

[0320] <Color development / decolorization drive> The color development and fading of the electrochromic element of Example 3-1 prepared was confirmed in the same manner as the electrochromic elements of Examples 1 and 2. As a result, when a voltage of -2 V was applied for 5 seconds between the lead portion of the first electrode and the lead portion of the second electrode, the overlapping portion of the first electrode and the second electrode was confirmed to be black, a mixture of blue and orange originating from the electrochromic compound of the electrochromic layer. Furthermore, when a voltage of +2 V was applied for 5 seconds between the lead portion of the first electrode and the lead portion of the second electrode, it was confirmed that the colored portion was decolorized and became transparent.

[0321] (Comparative Examples 3-1 to 3-3) Electrochromic elements were produced in the same manner as in Example 3-1, except that first electrochromic compositions were used in which exemplary compound 1 used in the first electrochromic compound in Example 3-1 was replaced with comparative compounds 1, 2, and 3. It was confirmed that the electrochromic elements of comparative examples 3-1 to 3-3 also produced a black color that combined blue and orange, similar to the electrochromic element of Example 3-1.

[0322] <Evaluation> Using each of the prepared electrochromic devices, a repeated durability test and a continuous color development test were carried out. The results are shown in Table 3.

[0323] <Test 3-1: Repeated durability test> For each of the electrochromic elements fabricated in Examples and Comparative Examples, a voltage of 2 V was applied between the lead portion of the first electrode and the lead portion of the second electrode for 5 seconds, followed by a voltage of -2 V for 5 seconds, which constituted one color-developing / decoloring driving operation. This color-developing / decoloring driving operation was repeated 10,000 times. The absorption maxima in the visible region (380 nm to 780 nm) at this time were defined as λmax (490 nm and 660 nm in the case of Example 3-1, with 490 nm as the reference). The change in absorbance at this time was measured using a spectrometer (USB4000, manufactured by Ocean Optics) and evaluated according to the following criteria. [Evaluation criteria] ○: When the absorbance of λmax is 95% or more compared to the initial state △: When the absorbance at λmax is 90% or more but less than 95% of the initial state ×: When the absorbance at λmax is less than 90% of the initial value

[0324] [Test 3-2: Continuous color development test] For each of the electrochromic devices fabricated in Examples and Comparative Examples, a voltage of 1.6 V was applied between the first and second electrodes, and the color-developed state was maintained for 48 hours. The absorbance in the visible region (380 nm to 780 nm) before and after the voltage application was measured using a spectrometer (USB4000, manufactured by Ocean Optics), and the yellow index (YI) was calculated. The difference between the YI before and after the voltage application was taken as ΔYI, and the results were evaluated according to the following criteria. [Evaluation criteria] ○: ΔYI is less than 0.5 △: ΔYI is 0.5 or more and less than 3 ×: ΔYI is 3 or more

[0325] [Test 3-3: Light durability test] For each of the electrochromic elements fabricated in Examples and Comparative Examples, a voltage of 1.6 V was applied between the first and second electrodes. While maintaining the color-developed state of the electrochromic element, it was irradiated with artificial sunlight (product name: SOLAX XC-100W, manufactured by Seric Co., Ltd., 150,000 lux) through a UV-cut filter (product name: Lumicool 1501UH, manufactured by Lintec Corporation) for 48 hours. The electrochromic element was then irradiated with deuterium tungsten halogen light (product name: DH-2000, manufactured by Ocean Optics Inc.). The transmittance in the visible region (380 nm to 780 nm) before and after irradiation was measured using a spectrometer (USB4000, manufactured by Ocean Optics Inc.). The yellow index (YI) was calculated, and the difference between the YI values ​​before and after irradiation was defined as ΔYI. The evaluation was based on the following criteria. [Evaluation criteria] ○: When ΔYI is less than 5 △: When ΔYI is 5 or more and less than 10 ×: ΔYI is 10 or more [Table 3] From the results in Table 3, it was confirmed that the electrochromic elements of Example 3-1 and Comparative Examples 3-1 to 3-3 all produced a black color that was a combination of blue and orange, and therefore, that the black color was produced by including a benzidine compound in the first electrochromic composition. Furthermore, from the results in Table 3, it was confirmed that the electrochromic element of Example 3-1 satisfied both the repeated durability and continuous color development, and was excellent in continuous driving stability and light durability. In contrast, it was confirmed that the electrochromic elements of Comparative Examples 3-1 to 3-3 were insufficient in any of the repeated durability, continuous color development, and light durability, and had somewhat inferior properties. Therefore, it can be said that the first electrochromic composition contributes to improving the continuous driving stability and light durability of the electrochromic element.

[0326] Example 4-1 <Fabrication of the fourth electrochromic element> An electrochromic element was produced in the same manner as in Example 2-1, except that, as electrochromic compound 2-1, exemplary compound M1 and exemplary compound TPAM1 were mixed in equal parts (50 parts by mass).

[0327] <Evaluation> Using each of the prepared electrochromic devices, a repeated durability test and a continuous color development test were carried out. The results are shown in Table 4.

[0328] (Coloring and decoloring drive) The color development and decolorization of the electrochromic element of Example 4 was confirmed in the same manner as the electrochromic elements of Examples 1 and 2. As a result, when a voltage of 2 V was applied for 5 seconds between the lead portion of the first electrode and the lead portion of the second electrode, the overlapping portion of the first electrode and the second electrode was confirmed to be black, a mixture of blue and orange originating from the electrochromic compound of the electrochromic layer. Furthermore, when a voltage of -2 V was applied for 5 seconds between the lead portion of the first electrode and the lead portion of the second electrode, it was confirmed that the colored portion was decolorized and became transparent.

[0329] (Comparative Examples 4-1 to 4-3) Electrochromic elements were prepared in the same manner as in Example 4-1, except that the exemplary compound M1 used in electrochromic compound 2-1 in Example 4-1 was changed to comparative compounds m1, m2, and m3. It was confirmed that the electrochromic elements of Comparative Examples 4-1 to 4-3 also produced a black color that combined blue and orange, similar to the electrochromic element of Example 4-1.

[0330] <Evaluation> Using each of the produced electrochromic devices, a repeated durability test, a continuous color development test, and a light durability test were carried out. The results are shown in Table 4.

[0331] [Test 4-1: Repeated durability test] For each of the electrochromic elements fabricated in Examples and Comparative Examples, a voltage of 2 V was applied between the lead portion of the first electrode and the lead portion of the second electrode for 5 seconds, followed by a voltage of -2 V for 5 seconds, which constituted one color-developing / decoloring driving operation. This color-developing / decoloring driving operation was repeated 10,000 times. The absorption maxima in the visible region (380 nm to 780 nm) at this time were defined as λmax (490 nm and 660 nm in the case of Example 4-1, with 490 nm as the reference). The change in absorbance at this time was measured using a spectrometer (USB4000, manufactured by Ocean Optics) and evaluated according to the following criteria. [Evaluation criteria] ○: When the absorbance of λmax is 95% or more compared to the initial state △: When the absorbance at λmax is 90% or more but less than 95% of the initial state ×: When the absorbance at λmax is less than 90% of the initial value

[0332] [Test 4-2: Continuous color development test] For each of the electrochromic devices fabricated in Examples and Comparative Examples, a voltage of 1.6 V was applied between the first and second electrodes, and the color-developed state was maintained for 48 hours. The absorbance in the visible region (380 nm to 780 nm) before and after the voltage application was measured using a spectrometer (USB4000, manufactured by Ocean Optics), and the yellow index (YI) was calculated. The difference between the YI before and after the voltage application was taken as ΔYI, and the results were evaluated according to the following criteria. [Evaluation criteria] ○: ΔYI is less than 0.5 △: ΔYI is 0.5 or more and less than 3 ×: ΔYI is 3 or more

[0333] [Test 4-3: Light durability test] For each of the electrochromic elements fabricated in Examples and Comparative Examples, a voltage of 1.6 V was applied between the first and second electrodes. While maintaining the color-developed state of the electrochromic element, it was irradiated with artificial sunlight (product name: SOLAX XC-100W, manufactured by Seric Co., Ltd., 150,000 lux) through a UV-cut filter (product name: Lumicool 1501UH, manufactured by Lintec Corporation) for 48 hours. The electrochromic element was then irradiated with deuterium tungsten halogen light (product name: DH-2000, manufactured by Ocean Optics Inc.). The transmittance in the visible region (380 nm to 780 nm) before and after irradiation was measured using a spectrometer (USB4000, manufactured by Ocean Optics Inc.). The yellow index (YI) was calculated, and the difference between the YI values ​​before and after irradiation was defined as ΔYI. The evaluation was based on the following criteria. [Evaluation criteria] ○: When ΔYI is less than 5 △: When ΔYI is 5 or more and less than 10 ×: ΔYI is 10 or more

[0334] [Table 4] From the results in Table 4, it was confirmed that the electrochromic elements of Example 4-1 and Comparative Examples 4-1 to 4-3 all produced a black color that combined blue and orange, and that the black color was produced by including a benzidine compound in electrochromic compound 2-1. Furthermore, from the results of Table 4, it was confirmed that the electrochromic element of Example 4-1 satisfied both the repeated durability and continuous color development, and was excellent in continuous driving stability and light durability. In contrast, it was confirmed that the electrochromic elements of Comparative Examples 4-1 to 4-3 were insufficient in any of the repeated durability, continuous color development, and light durability, and had somewhat inferior properties. Therefore, it can be said that the electrochromic compound 2-1 contributes to improving the continuous driving stability and light durability of the electrochromic device.

[0335] The present invention includes, for example, the following aspects. <1> a first electrode; a second electrode facing the first electrode at a distance; an electrolyte layer provided between the first electrode and the second electrode; An electrochromic element having The electrochromic element is characterized by having a layer containing an electrochromic compound represented by the following general formula (1) on the first electrode. [ka] In the general formula (1), R1 to R4 are all monovalent organic groups that do not have a hydrogen atom at the benzyl position, and may have a polymerizable functional group as a partial structure. R5~R 28 represents a hydrogen atom, an alkyl group, or an alkoxy group, and R 25 and R 28 or R 26 and R 27 may be bonded to each other to form a structure represented by the following general formula (2). [ka] However, in the general formula (2), R 29 and R 30 represents an alkyl group, an alkoxy group, or an aryl group, and R 29 and R 30 When both of the groups are aryl groups, they may form a cyclic structure via a common bond. <2> a first electrode; a second electrode facing the first electrode at a distance; an electrolyte layer provided between the first electrode and the second electrode; An electrochromic element having The electrochromic element is characterized in that the electrolyte layer contains an electrochromic compound represented by the following general formula (1): [ka] In the general formula (1), R1 to R4 are all monovalent organic groups that do not have a hydrogen atom at the benzyl position, and may have a polymerizable functional group as a partial structure. R5~R 28 represents a hydrogen atom, an alkyl group, or an alkoxy group, and R 25 and R 28 or R 26 and R 27 may be bonded to each other to form a structure represented by the following general formula (2). [ka] However, in the general formula (2), R 29 and R 30 represents an alkyl group, an alkoxy group, or an aryl group, and R 29 and R 30 When both of the groups are aryl groups, they may form a cyclic structure via a common bond. <3> the monovalent organic group having no hydrogen at the benzyl position is any one selected from a tertiary butyl group, a trialkylsilyl group, a triarylsilyl group, a diallylmonoalkylsilyl group, an alkoxy group, and a phenoxy group; <1> from <2> The electrochromic device according to any one of the above items. <4> In the general formula (1), R1 to R 28 any one of the above is a group containing a polymerizable functional group. <1> from <3> The electrochromic device according to any one of the above items. <5> The polymerizable functional group is either a (meth)acryloyl group or a (meth)acryloxy group. <4> 1. An electrochromic device according to claim 1. <6> R 13 From R 24 are all hydrogen atoms, <1> from <5> The electrochromic device according to any one of the above items. <7> The electrochromic compound is characterized by being represented by the following general formula (1). [ka] In the general formula (1), R1 to R4 are all monovalent organic groups that do not have a hydrogen atom at the benzyl position, and may have a polymerizable functional group as a partial structure. R5~R 28 represents a hydrogen atom, an alkyl group, or an alkoxy group, and R 25 and R 28 or R 26 and R 27 may be bonded to each other to form a structure represented by the following general formula (2). [ka] However, in the general formula (2), R 29 and R 30 represents an alkyl group, an alkoxy group, or an aryl group, and R 29 and R 30 When both of the groups are aryl groups, they may form a cyclic structure via a common bond. <8> the monovalent organic group having no hydrogen at the benzyl position is any one selected from a tertiary butyl group, a trialkylsilyl group, a triarylsilyl group, a diallylmonoalkylsilyl group, an alkoxy group, and a phenoxy group; <7> The electrochromic compound is described in <9> In the general formula (1), R1 to R 28 any one of the above is a group containing a polymerizable functional group. <7> from <8> The electrochromic compound according to any one of the above items. <10> The polymerizable functional group is either a (meth)acryloyl group or a (meth)acryloxy group. <9> The electrochromic compound is described in <11> R 13 From R 24 are all hydrogen atoms, <7> from <10> The electrochromic compound according to any one of the above items. <12> The aforementioned <7> from <11> 1. An electrochromic composition comprising the electrochromic compound according to any one of claims 1 to 9. <13> The above-mentioned composition further containing another radical polymerizable compound. <12> The electrochromic composition is as described in <14> The polymerizable functional group contained in the electrochromic composition is polymerized or crosslinked. <12> from <13> The electrochromic composition according to any one of the above items. <15> a first electrode; a second electrode facing the first electrode at a distance; an electrolyte layer provided between the first electrode and the second electrode; An electrochromic element having The aforementioned <12> from <14> and a layer containing the electrochromic composition according to any one of the above items on the first electrode. <16> a first electrode; a second electrode facing the first electrode at a distance; an electrolyte layer provided between the first electrode and the second electrode; An electrochromic element having The electrolyte layer is <12> from <14> 1. An electrochromic device comprising the electrochromic composition according to any one of claims 1 to 9.

[0336] The aforementioned <1> from <6> and <15> from <16> The electrochromic element according to any one of <7> from <11> The electrochromic compound according to any one of the above, <12> from <14> According to the electrochromic composition described in any one of the above, the conventional problems can be solved and the object of the present invention can be achieved. [Explanation of symbols]

[0337] 10A electrochromic element 10B Electrochromic element 11 First support 12 Display electrode 13 First electrochromic layer 14A electrolyte layer 14B Electrolyte layer 15 Second electrochromic layer 16 Counter electrode 17 Second Support [Prior art documents] [Patent documents]

[0338] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-038572 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-209300

Claims

1. a first electrode; a second electrode facing the first electrode at a distance; an electrolyte layer provided between the first electrode and the second electrode; An electrochromic element having An electrochromic element comprising a layer containing an electrochromic compound represented by the following general formula (1) on the first electrode: 【Chemical 1】 However, in the general formula (1), R １ ~R ４ are all monovalent organic groups having no hydrogen atom at the benzyl position, and any one of them is a group having a polymerizable functional group at its terminal (excluding the case where all four of R 1 to R 4 are groups having a polymerizable functional group), and R ５ ~R ２８ represents a hydrogen atom, an alkyl group, or an alkoxy group; R ２５ and R ２８ or R ２６ and R ２７ may be bonded to each other to form a structure represented by the following general formula (2). 【Chemistry 2】 However, in the general formula (2), R ２９ and R ３０ represents an alkyl group, an alkoxy group, or an aryl group; R ２９ and R ３０ When both of the groups are aryl groups, they may form a cyclic structure via a common bond.

2. a first electrode; a second electrode facing the first electrode at a distance; an electrolyte layer provided between the first electrode and the second electrode; An electrochromic element having The electrochromic element is characterized in that the electrolyte layer contains an electrochromic compound represented by the following general formula (1): 【Chemistry 3】 However, in the general formula (1), R １ ~R ４ are all monovalent organic groups having no hydrogen atom at the benzyl position, and any one of them is a group having a polymerizable functional group at its terminal (excluding the case where all four of R 1 to R 4 are groups having a polymerizable functional group), and R ５ ~R ２８ represents a hydrogen atom, an alkyl group, or an alkoxy group; R ２５ and R ２８ or R ２６ and R ２７ may be bonded to each other to form a structure represented by the following general formula (2). 【Chemistry 4】 However, in the general formula (2), R ２９ and R ３０ represents an alkyl group, an alkoxy group, or an aryl group; R ２９ and R ３０ When both of the groups are aryl groups, they may form a cyclic structure via a common bond.

3. 3. The electrochromic device according to claim 1, wherein the monovalent organic group having no hydrogen at the benzyl position is any one selected from a tertiary butyl group, a trialkylsilyl group, a triarylsilyl group, a diallylmonoalkylsilyl group, an alkoxy group, and a phenoxy group.

4. 4. The electrochromic device according to claim 1, wherein the polymerizable functional group is either a (meth)acryloyl group or a (meth)acryloxy group.

5. R １３ From R ２４ The electrochromic device according to claim 1 , wherein all of are hydrogen atoms.

6. An electrochromic composition comprising an electrochromic compound represented by the following general formula (1): 【Chemistry 5】 However, in the general formula (1), R １ ~R ４ are all monovalent organic groups having no hydrogen atom at the benzyl position, and any one of them is a group having a polymerizable functional group at its terminal (excluding the case where all four of R 1 to R 4 are groups having a polymerizable functional group), and R ５ ~R ２８ represents a hydrogen atom, an alkyl group, or an alkoxy group; R ２５ and R ２８ or R ２６ and R ２７ may be bonded to each other to form a structure represented by the following general formula (2). 【Chemistry 6】 However, in the general formula (2), R ２９ and R ３０ represents an alkyl group, an alkoxy group, or an aryl group; R ２９ and R ３０ When both of the groups are aryl groups, they may form a cyclic structure via a common bond.

7. 7. The electrochromic composition according to claim 6, wherein the monovalent organic group having no hydrogen at the benzyl position is any one selected from a tertiary butyl group, a trialkylsilyl group, a triarylsilyl group, a diallylmonoalkylsilyl group, an alkoxy group, and a phenoxy group.

8. 8. The electrochromic composition according to claim 6, wherein the polymerizable functional group is either a (meth)acryloyl group or a (meth)acryloxy group.

9. R １３ From R ２４ The electrochromic composition according to any one of claims 6 to 8, wherein all of are hydrogen atoms.

10. An electrochromic composition according to claim 6, further comprising a radical polymerizable compound other than the electrochromic compound represented by general formula (1).

11. An electrochromic composition characterized by being a copolymer obtained by polymerizing an electrochromic compound represented by the following general formula (1): 【Chemistry 7】 In the general formula (1), R 1 to R 4 are all monovalent organic groups that do not have a hydrogen atom at the benzyl position, and any one of them is a group having a polymerizable functional group at its terminal (excluding the case where all four of R 1 to R 4 are groups having a polymerizable functional group), R 5 to R 28 represent a hydrogen atom, an alkyl group or an alkoxy group, and R 25 and R 28 or R 26 and R 27 may be bonded to each other to form a structure represented by the following general formula (2): 【Chemistry 8】 In the general formula (2), R 29 and R 30 represent an alkyl group, an alkoxy group, or an aryl group, and when both R 29 and R 30 are aryl groups, they may form a cyclic structure via a common bond.

12. a first electrode; a second electrode facing the first electrode at a distance; an electrolyte layer provided between the first electrode and the second electrode; An electrochromic element having An electrochromic device comprising a layer containing the electrochromic composition according to any one of claims 6 to 11 on the first electrode.

13. a first electrode; a second electrode facing the first electrode at a distance; an electrolyte layer provided between the first electrode and the second electrode; An electrochromic element having 12. An electrochromic device, wherein the electrolyte layer contains the electrochromic composition according to claim 6.

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