JP6888321B2 - Electrochromic element - Google Patents

Description

The present invention relates to electrochromic devices.

When a voltage is applied, oxidation and reduction occur reversibly, and the phenomenon of reversible coloring and decolorization is called electrochromism. Previous attempts have been made to use electrochromic elements for light intensity control elements (for example, dimming glass, dimming lenses, etc.) by creating electrochromic elements that are colored and decolorized by voltage manipulation and using a transparent base material. It is done from.

As a method for producing an electrochromic device, a method is known in which an electrolytic layer containing an electrolyte is sandwiched between a display electrode and a counter electrode on which an oxide layer and a reduction layer are formed. In this case, in the conventional manufacturing process, a spacer is used to prevent a short circuit between the electrodes during bonding.
However, conventionally, spherical beads or the like are used as spacers, and the beads are made of resin or glass. However, if the difference in refractive index from the electrolytic layer is large, haze deteriorates or uneven coloring occurs. There was a problem with optical characteristics such as the occurrence of.

Patent Document 1 discloses an electrochromic mirror in which the difference in refractive index between the beads used for the spacer and the electrolytic layer is ± 0.03 or less for the purpose of ensuring the optical characteristics while maintaining the cell gap. ..
Further, Patent Documents 2 and 3 disclose a method in which an electrolyte layer containing a polymer binder and a spacer is formed on an electrode and another electrode is attached to the electrode, and the average particle size of the spacer and the average particle size of the spacer are disclosed. The film thickness of the electrolyte layer is made substantially equal. In this way, we are trying to eliminate uneven coloring.

However, in the past, even if the optical characteristics could be ensured, the spacer did not contribute to the redox reaction, so that the spacer portion affected the color decolorization reaction, and a good color decolorization reaction was obtained in terms of electrical characteristics. There wasn't. Therefore, an electrochromic device having good optical and electrical characteristics has been required.

An object of the present invention is to provide an electrochromic device having good optical and electrical characteristics.

In order to solve the above problems, the electrochromic element of the present invention includes a first conductive substrate, a first electrochromic layer formed in contact with the first conductive substrate, and the first conductive substrate. It has a second conductive substrate facing each other, a second electrochromic layer formed in contact with the second conductive substrate, and an electrolyte layer having a spacer, and the first electrochromic layer and the first electrochromic layer. the second electrochromic layer face each other through the electrolyte layer, wherein the spacer is viewed contains an electrolyte and a resin, characterized in that formed by patterning the projection shape.

According to the present invention, it is possible to provide an electrochromic device having good optical characteristics and electrical characteristics.

It is schematic cross-sectional view along the thickness direction which shows an example of the electrochromic element of this invention. It is schematic cross-sectional view along the plane direction which shows an example of the electrochromic element of this invention.

Hereinafter, the electrochromic device according to the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments shown below, and can be modified within the range conceivable by those skilled in the art, such as other embodiments, additions, modifications, and deletions. However, as long as the action and effect of the present invention are exhibited, it is included in the scope of the present invention.

An embodiment of an electrochromic device will be described in the present invention. The electrochromic device of this embodiment is shown in FIGS. 1 and 2. FIG. 1 is a schematic cross-sectional view of the electrochromic element of the present embodiment along the thickness direction. FIG. 2 is a schematic cross-sectional view taken along the plane direction of the electrochromic element of the present embodiment, and is a cross-sectional view taken along the line AA in FIG.

The electrochromic element of the present embodiment includes a first conductive substrate 1, a first electrochromic layer 3 formed in contact with the first conductive substrate 1, and a second conductive substrate 1 facing the first conductive substrate 1. It has a conductive substrate 2, a second electrochromic layer 4 formed in contact with the second conductive substrate 2, and an electrolyte layer 5 having a spacer 6. The first electrochromic layer 3 and the second electrochromic layer 4 face each other via the electrolyte layer 5, and the spacer 6 contains an electrolyte and a resin.

Although the details will be described later, it is preferable that the first conductive substrate 1 and the second conductive substrate 2 are transparent, and when the electrochromic element is decolorized, the first electrochromic layer 3 and the second electrochromic layer 4 are used. And the electrolyte layer 5 is preferably transparent.

<First conductive substrate and second conductive substrate>
A conductive substrate refers to a substrate that functions as an electrode. In the present embodiment, the first electrode 1b may be formed on the first substrate 1a to form the first conductive substrate 1. Further, the second electrode 2b may be formed on the second substrate 2a to form the second conductive substrate 2.
Examples of the substrate (first substrate 1a, second substrate 2a) include glass and a plastic substrate. As the plastic base material, known materials such as PET (polyethylene terephthalate) resin and PC (polycarbonate) resin can be used. It is preferable to use a transparent support as the substrate.

The first electrode 1b and the second electrode 2b are preferably made of a transparent conductive material, and are preferably indium tin oxide (tin-doped indium oxide) (hereinafter referred to as “ITO”) and fluorine-doped tin oxide (hereinafter referred to as “ITO”). Hereinafter, examples thereof include inorganic materials such as "FTO"), indium tin oxide doped with antimony (hereinafter referred to as "ATO"), and zinc oxide. Furthermore, transparent carbon nanotubes and other highly conductive non-transparent materials such as Au, Ag, Pt, and Cu are formed in a fine network to improve conductivity while maintaining transparency. Electrodes may be used. Among these, ITO is suitable as an electrode included in the electrochromic element of the present invention because high adhesion can be obtained.

As a method for producing the first electrode 1b and the second electrode 2b, for example, a vacuum vapor deposition method, a sputtering method, an ion plating method, or the like can be used. When the material of the first electrode 1b and the second electrode 2b is a material that can be applied and formed, for example, a spin coating method, a casting method, a microgravure coating method, a gravure coating method, a bar coating method, a roll coating method, and a wire. Bar coating method, dip coating method, slit coating method, capillary coating method, spray coating method, nozzle coating method, gravure printing method, screen printing method, flexographic printing method, offset printing method, reverse printing method, inkjet printing method, etc. A printing method can be used.

The film thicknesses of the first electrode 1b and the second electrode 2b are not particularly limited and can be appropriately changed. For example, when ITO is used, the film thickness is preferably about 50 nm or more and 500 nm or less.

As the first conductive substrate 1 and the second conductive substrate 2, a transparent substrate is used for the first substrate 1a and the second substrate 2a, and a transparent electrode is used for the first electrode 1b and the second electrode 2b. It is preferable to make it transparent.

<First electrochromic layer and second electrochromic layer>
Next, the first electrochromic layer 3 and the second electrochromic layer 4 in the present embodiment will be described.
Hereinafter, when the term "electrochromic layer" is used, the first electrochromic layer 3 and the second electrochromic layer 4 are not distinguished, and both will be described.
Further, the first electrochromic layer may be referred to as a display electrode, and the second electrochromic layer may be referred to as a counter electrode. Further, in the present embodiment, the first electrochromic layer will be described as an oxide layer using an oxidized electrochromic compound, and the second electrochromic layer will be described as a reduced layer using a reduced electrochromic compound. It is not something that can be done.

As a material for forming the electrochromic layer, for example, an electrochromic compound is prepared by mixing it with a binder, a solvent, an additive or the like.

In the present embodiment, an oxidized electrochromic compound is used for the first electrochromic layer 3. The first electrochromic layer 3 is a first electrochromic layer containing a radically polymerizable compound having a triarylamine structure and another radically polymerizable compound different from the radically polymerizable compound having the triarylamine structure. It is preferably a crosslinked product obtained by cross-linking the layer-forming material. In this case, it is preferable in terms of solubility and durability of the polymer.
Further, by having a radically polymerizable compound having a triarylamine structure, a better color decolorization reaction can be exhibited.

The binder is not particularly limited, and a known polymer resin can be used. For example, other radically polymerizable compounds different from the above-mentioned radically polymerizable compound having a triarylamine structure can be mentioned.
The other radically polymerizable compound is a compound having at least one radically polymerizable functional group, unlike the radically polymerizable compound having the triarylamine structure.
Examples of the other radical-polymerizable compounds include monofunctional radical-polymerizable compounds, bifunctional radical-polymerizable compounds, trifunctional or higher-functional radical-polymerizable compounds, functional monomers, and radical-polymerizable oligomers. Among these, a radically polymerizable compound having two or more functions is particularly preferable.

The material for forming the first electrochromic layer 3 undergoes a cross-linking reaction between the radically polymerizable compound having the triarylamine structure and another radically polymerizable compound different from the radically polymerizable compound having the triarylamine structure. It is preferable to contain a polymerization initiator as necessary in order to proceed efficiently.
The polymerization initiator can be changed as appropriate, and examples thereof include a thermal polymerization initiator and a photopolymerization initiator. A photopolymerization initiator is preferable from the viewpoint of polymerization efficiency.

The method for forming the electrochromic layer is not particularly limited and can be appropriately changed. For example, inkjet, screen printing, gravure printing, die coating, spray coating, flexographic printing and the like can be mentioned.

In the present embodiment, a reduced electrochromic compound is used for the second electrochromic layer 4. Examples of the reduced electrochromic compound include azobenzene-based, anthraquinone-based, diarylethane-based, dihydroprene-based, dipyridine-based, styryl-based, styrylspiropirane-based, spiroxazine-based, spirothiopyran-based, thioindigo-based, tetrathiafluvalene-based, and terephthalic acid. System, triphenylmethane system, triphenylamine system, naphthopyrane system, viologen system, pyrazoline system, phenazine system, phenylenediamine system, phenoxazine system, phenothiazine system, phthalocyanine system, fluorane system, flugide system, benzopyran system, metallocene system, etc. Low molecular weight organic electrochromic compounds and the like. These may be used alone or in combination of two or more.

The second electrochromic layer 4 may have a structure in which an organic electrochromic compound is supported on conductive or semiconductor fine particles. Specifically, it has a structure in which fine particles having a particle size of, for example, about 5 nm to 50 nm are sintered on the surface of the electrode, and an organic electrochromic compound having a polar group such as a phosphonic acid, a carboxyl group, or a silanol group is adsorbed on the surface of the fine particles. is there.

In such a structure, electrons are efficiently injected into the organic electrochromic compound by utilizing the large surface effect of the fine particles, so that a high-speed response is possible as compared with the conventional electrochromic display device. Further, since a transparent film can be formed by using fine particles, a high color density of the electrochromic dye can be obtained. Further, a plurality of types of organic electrochromic compounds can be supported on conductive or semiconductor fine particles.

The average thickness of the electrochromic layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.2 μm to 5.0 μm. If the average thickness is less than 0.2 μm, it may be difficult to obtain the color development density, and if it exceeds 5.0 μm, the manufacturing cost may increase and the visibility may easily decrease due to coloring.

<Electrolyte layer>
The electrolyte layer 5 is a layer capable of conducting ions for supplying ions to the electrochromic layer. Further, the electrolyte layer 5 is preferably a transparent layer because of its properties as a display element of the electrochromic element. The electrolyte layer 5 has a spacer 6, an electrolyte, and further contains an electrolyte solvent and other components, if necessary.

The electrolyte layer 5 can be in the form of a liquid, a solid, a gel, a polymer crosslinked type, or the like. By forming the electrolyte layer 5 in the form of a gel or a solid, advantages such as improvement in device strength and improvement in reliability can be obtained. In particular, it is preferable to form a gel that can maintain high ionic conductivity. As a gelling method, it is preferable to retain the electrolyte, the electrolyte solvent and other components in the polymer resin. As a result, high ionic conductivity and solid strength can be obtained.

As the electrolyte, for example, inorganic ion salts such as alkali metal salts and alkaline earth metal salts can be used, and quaternary ammonium salts, acids, supporting salts of alkalis and the like can be used. Specifically, LiClO ₄ , LiBF ₄ and the like can be used. Examples thereof include LiAsF ₆ , LiPF _{6 , LiCF 3} SO ₃ , LiCF ₃ COO, KCl, NaClO ₃ , NaCl, NaBF ₄ , NaSCN, KBF ₄ , Mg (ClO ₄ ) ₂ , Mg (BF ₄ ) ₂ .

An ionic liquid can also be used as the electrolyte. Among these, organic ionic liquids are preferable because they have a molecular structure that exhibits a liquid in a wide temperature range including room temperature.
Examples of the ionic liquid include 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide (EMIMTFSI, manufactured by Kanto Chemical Co., Ltd.), ethylmethylimidazolium tetracyanoborate (EMIMTCB, manufactured by Merck), and ethylmethyl. Imidazolium tripentafluholoethyl trifluoroolophosphate (EMIMFAP, manufactured by Merck), allylbutyl imidazolium tetrafluoroborate (ABIMBF4, manufactured by Kanto Chemical Co., Ltd.), methylpropylpyrrolidinium bisfluorosulfonimide (P13FSI, manufactured by Kanto Chemical Co., Ltd.) A liquid in which (manufactured by) is dissolved. These may be used alone or in combination of two or more.

The ionic liquid may be dissolved directly in any of the photopolymerizable monomers, oligomers, and liquid crystal materials. If the solubility is poor, the solution may be dissolved in a small amount of solvent and mixed with any of a photopolymerizable monomer, an oligomer, and a liquid crystal material.

The average thickness of the electrolyte layer 5 is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 100 nm or more and 100 μm or less.

Examples of the solvent include propylene carbonate, acetonitrile, γ-butyrolactone, ethylene carbonate, sulfolane, dioxolane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, 1,2-dimethoxyethane, 1,2-ethoxymethoxyethane, and polyethylene glycol. , Alcohols, or a mixed solvent thereof and the like.

As the polymer resin, a photocurable resin is preferable. This is because an electrochromic device can be manufactured at a low temperature and in a short time as compared with a method of forming a thin film by thermal polymerization or evaporation of a solvent.

Further, as the polymer resin, a methacrylate-based polymer and an acrylate-based polymer are preferable. The polymer is preferably obtained by photocuring a compound having at least one radically polymerizable functional group. As the radically polymerizable compound, the same compounds as those mentioned as the binder of the electrochromic layer can be used. For example, a monofunctional radical polymerizable compound, a bifunctional radical polymerizable compound, a trifunctional or higher functional radical polymerizable compound, a functional monomer, a radical polymerizable oligomer and the like can be mentioned. These can be used alone or in combination of multiple types.

A gelled electrolyte layer can be obtained by mixing the compound having a radically polymerizable functional group with the electrolyte, an electrolyte solvent, and other components described below and photocuring.

The other components are not particularly limited and may be appropriately selected depending on the intended purpose. For example, a solvent, a plasticizer, a polymerization initiator, a leveling agent, a sensitizer, a dispersant, a surfactant, and an antioxidant can be selected. Examples include agents and fillers.

<< Spacer >>
Conventionally, spacers have been used in the electrolyte layer for the purpose of preventing short circuits between electrodes when manufacturing electrochromic devices. The conventional spacer becomes an insulator that does not contribute to the redox reaction. However, since the spacer does not contribute to the redox reaction, the spacer portion affects the color decolorization reaction, and a good color decolorization reaction has not been obtained in terms of electrical characteristics.

On the other hand, when the spacer 6 of the present embodiment contains an electrolyte, it can contribute to the color decolorization reaction and improve the electrical characteristics of the color decolorization. Further, since the spacer 6 contains an electrolyte, the refractive indexes of the electrolyte layer and the spacer can be brought close to each other, so that the internal haze can be reduced and the optical characteristics can be improved.

The spacer 6 of the present embodiment contains an electrolyte and a resin. Examples of the electrolyte contained in the spacer 6 include an electrolyte that can be used for the above-mentioned electrolyte layer 5. Above all, the ionic liquid is preferable.

The electrolyte contained in the spacer 6 may be the same as or different from the electrolyte contained in the electrolyte layer 5, but the electrolyte contained in the spacer 6 is the same as the electrolyte contained in the electrolyte layer 5. It preferably contains an ingredient. In this case, the difference in the refractive index between the spacer and the electrolyte layer can be made smaller, and the optical characteristics are improved.

The resin contained in the spacer 6 can be appropriately changed, and examples thereof include a resin that can be used for the above-mentioned electrolyte layer 5.

The content of the electrolyte contained in the spacer 6 can be changed as appropriate, but for example, it is preferably contained in an amount of 1% by mass or more and 80% by mass or less with respect to the spacer. In this case, the spacer can contribute to the decolorization reaction, the resin content can be appropriately adjusted, and the strength required to prevent short-circuiting of the electrodes can be imparted.

The shape of the spacer 6 is not particularly limited and can be changed as appropriate. For example, as shown in the cross-sectional view taken along the thickness direction of FIG. 1, it may have a tapered shape, or it may have another shape such as a circular shape or a rectangular shape. Further, as shown in the cross-sectional view taken along the plane direction of FIG. 2, it may have a circular shape, or may have another shape such as a rectangular shape.

The height of the spacer is substantially the thickness of the electrolyte layer, but is not particularly limited and can be appropriately selected depending on the intended purpose. The average height of the spacers is preferably 100 nm or more and 100 μm or less, for example.

Not all spacers contained in the electrolyte layer need to be in contact with the first electrochromic layer and the second electrochromic layer, and some may be in contact with either one or not. .. When the spacer is in contact with at least one of the first electrochromic layer and the second electrochromic layer, it is possible to more reliably prevent the electrodes from being short-circuited.

The proportion of the spacer contained in the electrolyte layer can be appropriately changed so as to improve the optical characteristics and the electrical characteristics, but for example, it is preferably contained in an amount of 1% by mass or more and 50% by mass or less with respect to the electrolyte layer. In this case, the spacer can contribute to the decolorization reaction and can have the strength required to prevent short-circuiting of the electrodes.

Further, the spacer and the electrolyte layer may have the same components, which can simplify the manufacturing process. In this case, the spacer is preferably harder than the electrolyte layer. When the same component and the same hardness are used, the coloring and decolorizing reaction can be improved, but the function of the spacer to prevent short-circuiting of the electrode is reduced. The hardness can be examined using a nano indenter or the like.

Next, a method for producing the spacer and the electrolyte layer in the present embodiment will be described.
First, a spacer forming material containing an electrolyte and a resin is applied onto the first electrochromic layer or the second electrochromic layer formed on the conductive substrate. The spacer forming material can be applied by inkjet, screen printing, gravure printing, dispenser or the like.
The spacer may be formed on either one of the first electrochromic layer and the second electrochromic layer, or may be formed on both.

After applying the spacer forming material on the electrochromic layer, it is cured. The curing method can be changed as appropriate, and examples thereof include a method of curing by UV exposure and a method of curing by heat.

After forming the spacer, the material for forming the electrolyte layer is applied onto the electrochromic layer on which the spacer is formed. The material for forming the electrolyte layer can be applied using, for example, a dispenser, screen printing, an inkjet, or the like.

Next, the conductive substrate on which the electrochromic layer is separately formed is attached to the conductive substrate on which the electrochromic layer and the spacer are formed. At this time, it may be bonded by pressing it while removing air with a laminator or a vacuum bonding machine.
Further, at the time of bonding, an adhesive or the like may be used to improve the adhesive strength. In this case, the adhesive can function as a sealing material.

Since the electrolyte layer functions even if it is in a liquid state, an electrochromic element can be obtained by bonding conductive substrates, but the electrolyte layer may be cured after bonding to form a solid or gel. When it is in the form of a solid or gel, it is possible to prevent liquid leakage and to manufacture a more reliable element.

When the material for forming the spacer and the material for forming the electrolyte layer are the same in the case of curing the electrolyte layer, it is preferable to cure both so that the spacer is harder than the electrolyte layer. In this case, the curing of the electrolyte layer is preferably lower than the integrated light intensity of the spacer.

<Encapsulant>
The sealing material 7 is not particularly limited and can be appropriately changed. For example, a resin such as an adhesive can be used. The sealing material 7 is used for the purpose of preventing the electrolyte layer 5 from sticking out and increasing the adhesive force between the substrates. The shape of the sealing material 7 is not particularly limited, and may be, for example, a shape as shown in FIGS. 1 and 2.
The thickness of the sealing material 7 with respect to the surface direction of the element is preferably, for example, 100 μm to 10 mm.

<Manufacturing method of electrochromic element>
As described above, the method for manufacturing the electrochromic element of the present embodiment includes a step of forming the first electrochromic layer on the first conductive substrate and a second electrochromic layer on the second conductive substrate. A step of forming, a step of applying a spacer forming material on the first electrochromic layer or the second electrochromic layer, and curing the material to form a spacer, and the first electrochromic layer and the first. The step of laminating the first conductive substrate and the second conductive substrate so that the two electrochromic layers face each other via the spacer, and the material for forming the electrolyte layer is the first electrochromic layer and the said. It has a step of forming an electrolyte layer by applying it between the second electrochromic layers. The spacer forming material contains an electrolyte and a resin.

Further, the spacer forming material and the electrolyte layer forming material can be produced with the same composition, and it is preferable that the spacer is formed so as to be harder than the electrolyte layer. In this case, the electrochromic device can be manufactured more easily.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples.

(Example 1)
<Conductive substrate>
As the conductive substrate, ITO glass (40 mm × 40 mm, glass thickness 0.7 mm, ITO thickness 100 nm) on which ITO was formed was used. The size of the color-decoloring portion of the element was 30 mm × 30 mm.

<Formation of the first electrochromic layer>
The first electrochromic layer forming material was prepared with the following composition.

[composition]
15% by mass of electrochromic compound represented by the following structural formula (1)
-Polyethylene glycol diacrylate (PEG400D manufactured by Nippon Kayaku Co., Ltd.) 14.25% by mass
-Photoinitiator (BASF's Irgacure 184) 0.75% by mass
・ Cyclohexanone 70% by mass

The first electrochromic layer forming material was dissolved by ultrasonic waves for 10 minutes. Then, after applying to a conductive substrate to a necessary place using an inkjet device, the solvent is dried on a hot plate at 80 ° C. for 1 minute, and then UV-exposed to a thickness of 1.3 μm. A first electrochromic layer was formed.

<Formation of a second electrochromic layer>
Titanium oxide nanoparticle dispersion liquid (SP210 manufactured by Showa Titanium Co., Ltd., average particle size 20 nm) is applied onto a conductive substrate by a spin coating method, and annealed at 120 ° C. for 15 minutes to obtain a 1.0 μm titanium oxide particle film. A nanostructured semiconductor material composed of Then, a material for forming a second electrochromic layer was prepared with the following composition.

[composition]
-Electrochromic compound represented by the following structural formula (2) 2% by mass
・ 2,2,3,3-tetrafluoropropanol 98% by mass

The second electrochromic layer forming material was applied to the semiconductor material obtained as described above by a spin coating method. Next, annealing treatment was performed at 120 ° C. for 10 minutes to form a second electrochromic layer having a thickness of 1.0 μm composed of a titanium oxide particle film and an electrochromic compound.

<Formation of electrolyte layer>
-Preparation of materials for forming electrolyte layer-
A material for forming an electrolyte layer was prepared with the following composition.

[composition]
1-Ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide 60% by mass
-Polyethylene glycol diacrylate (PEG400D manufactured by Nippon Kayaku Co., Ltd.) 20% by mass
・ Methoxypolyethylene glycol monoacrylate (NOF Corporation Blemmer PME) 18% by mass
-Photoinitiator (BASF's Irgacure 184) 2% by mass

-Preparation of materials for spacer formation-
A material for forming a spacer was prepared with the following composition.

[composition]
1-Ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide 30% by mass
-Polyethylene glycol diacrylate (PEG400D manufactured by Nippon Kayaku Co., Ltd.) 66.5% by mass
-Photoinitiator (BASF's Irgacure 184) 3.5% by mass

A spacer-forming material was patterned on the obtained first electrochromic layer so as to form protrusions of 30 μm using an inkjet device, and cured by UV exposure to form spacers. The curing conditions were irradiation with an integrated light intensity of 0.6 J / cm ^{2 at a wavelength of 240 to 275 nm.}
Then, the material for forming the electrolyte layer was filled on the first electrochromic layer using an aerojet dispenser. After filling the material for forming the electrolyte layer, the conductive substrates were bonded to each other using an optical adhesive. After bonding, the electrolyte layer was cured by UV exposure to form a gel. The curing conditions were irradiation with an integrated light intensity of 0.3 J / cm ^{2 at a wavelength of 240 to 275 nm.}

As described above, the electrochromic device of this example was produced. The obtained electrochromic device had the configuration shown in FIGS. 1 and 2. The optical adhesive was formed as a sealing material and was produced in a shape as shown in the figure.

(Example 2)
In Example 1, an electrochromic device was produced in the same manner as in Example 1 except that the same material as that for forming the electrolyte layer was used as the spacer forming material. The curing conditions such as the integrated light amount were the same as in Example 1.

(Comparative Example 1)
In the preparation of the spacer forming material of Example 1, only polyethylene glycol diacrylate and Irgacure 184 were used without adding an electrolyte. Other than that, an electrochromic device was produced in the same manner as in Example 1.

(Comparative Example 2)
In the preparation of the spacer forming material of Example 1, acrylic resin beads (micropearl manufactured by Sekisui Chemical Co., Ltd.) having a diameter of 30 μm were added without adding an electrolyte. Other than that, an electrochromic device was produced in the same manner as in Example 1.

(Comparative Example 3)
An electrochromic device was produced in the same manner as in Example 1 except that the spacer was not formed in Example 1.

(Measurement)
Haze was measured based on JIS-K-7136.
At the time of coloring, a voltage of −2.0 V was applied to the first electrochromic layer and the second electrochromic layer for 5 seconds, and the color unevenness visually evaluated at that time was evaluated. Those in which color unevenness could not be visually confirmed were marked with ◯, and those in which color unevenness could be confirmed were marked with x.
The memory property was marked with ◯ when the application of voltage was stopped after coloring and the color did not change for 30 seconds or more when left unattended.

The results are shown in Table 1.

In Comparative Example 1, since the electrolyte does not exist in the spacer, a portion that does not react at the time of coloring is formed, and uneven coloring occurs. Since beads are used in Comparative Example 2, it is difficult to control the haze, and as in Comparative Example 1, there is a portion that does not contribute to color loss, so that uneven coloring occurs. In Comparative Example 3, the first electrochromic layer and the second electrochromic layer come into contact with each other in the central portion and cause a short circuit, resulting in poor memory after coloring.
On the other hand, in Examples 1 and 2, haze, uneven coloring, and memory properties were good.
From the above, an electrochromic device having good optical and electrical characteristics can be obtained by the present invention.

1 1st conductive substrate 1a 1st substrate 1b 1st electrode 2 2nd conductive substrate 2a 2nd substrate 2b 2nd electrode 3 1st electrochromic layer 4 2nd electrochromic layer 5 Electrolyte layer 6 Spacer 7 Encapsulant

Japanese Patent No. 4360663 Japanese Unexamined Patent Publication No. 2008-139745 Japanese Unexamined Patent Publication No. 2008-145830

Claims (6)

The first conductive substrate and
A first electrochromic layer formed in contact with the first conductive substrate,
A second conductive substrate facing the first conductive substrate and
A second electrochromic layer formed in contact with the second conductive substrate,
With an electrolyte layer having a spacer,
The first electrochromic layer and the second electrochromic layer face each other via the electrolyte layer.
The spacer viewed contains an electrolyte and a resin, an electrochromic element characterized by formed by patterning the projection shape. The electrochromic device according to claim 1, wherein the electrolyte contained in the spacer contains the same components as the electrolyte contained in the electrolyte layer. The electrochromic device according to claim 1 or 2, wherein the spacer is in contact with at least one of the first electrochromic layer and the second electrochromic layer. The electrochromic device according to any one of claims 1 to 3, wherein the electrolyte is an ionic liquid. The electrochromic device according to any one of claims 1 to 4, wherein the first electrochromic layer or the second electrochromic layer has a radically polymerizable compound having a triarylamine structure. The first conductive substrate and the second conductive substrate are transparent and are transparent.
The electrochromic according to any one of claims 1 to 5, wherein the first electrochromic layer, the second electrochromic layer, and the electrolyte layer are transparent when the electrochromic element is decolorized. element.

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