JP6812634B2 - Electrochromic element - Google Patents

Description

The present invention relates to electrochromic devices.

Electrochromism is a phenomenon in which a redox reaction occurs reversibly by the transfer of electric charge and the color changes reversibly. The method of decolorizing by electrochemical redox reaction (hereinafter, electrochromic is sometimes called "EC") is a display element such as electronic paper, a light control lens, a light control glass, a light control window, etc. It is expected to be applied to dimming devices such as dimming mirrors.

In many of these EC device devices, a display composition containing a substance that develops and decolorizes by oxidation and reduction is sandwiched between two electrodes, and the electrolyte composition is sandwiched between the two electrodes to secure a certain interval. It is necessary to match. The color-developing characteristics of the created EC element depend not only on the display composition of the oxide electrode side EC layer and the reducing electrode side EC layer, but also on the thickness of the electrolyte layer sandwiched between them. Since the thickness of the electrolyte layer is related to the magnitude of ionic conductivity and the response speed, a technique for controlling the gap (thickness of the electrolyte composition) between two electrodes for the purpose of improving the characteristics of the EC element. Is disclosed (see, for example, Patent Documents 1 to 7).

Patent Document 1 discloses a method of arranging glass fibers or inorganic particles as spacer particles between two electrodes in order to keep the gap between the base materials constant. Patent Document 2 discloses a method of ensuring a constant gap even when a large screen is bonded by using a wire-shaped fiber as a spacer. Patent Document 3 discloses a method of inserting a fibrous rigid body into a polymer porous membrane. However, these techniques have a problem that the spacer can be visually confirmed due to the difference between the refractive index of the spacer and the refractive index of the electrolyte layer.

Therefore, a method of combining compositions so that the difference in refractive index between the glass beads used as a spacer and the ionic conduction layer used as an electrolyte layer is ± 0.03 or less as in Patent Document 4, or as in Patent Document 5. A method has been proposed in which a sealing material is applied to the ends of the two electrodes to keep the gap between the base materials constant without using glass beads or the like as a spacer. However, in these methods, when used as an EC element on a flexible PET film or a curved surface of spectacles having a curvature, the gap between the base materials may change due to pressing, which may affect the color development.

Further, Patent Document 6 proposes a method of treating the surface of the spacer with a reactive material to prevent the spacer from moving in the EC cell, and Patent Document 7 proposes a method in which the spacer is designated in the EC cell with a thixotropic agent. A method of fixing to a position has been proposed. In these conventional techniques, the gap between the base materials can be kept constant regardless of the rigidity and curvature of the base material, and the visibility of the spacer can also be suppressed. However, due to the difference in expansion and contraction of each layer, poor adhesion of each layer may occur due to external processing force during manufacturing and temperature change during actual use, which may affect color development and decolorization. Therefore, the current situation is that an electrochromic device that sufficiently satisfies both the retention of the gap between the electrodes and the adhesion of each layer provided between the electrodes is not provided.

The present invention has been made in view of the above circumstances, and has a spacer function capable of satisfactorily holding a gap between each layer provided between electrodes, and improves the adhesion between each layer. It is an object of the present invention to provide an electrochromic element capable of the above.

The electrochromic element of the present invention as a means for solving the above-mentioned problems includes a first electrode, a second electrode facing the first electrode at a distance, the first electrode, and the first electrode. An electrochromic element having an electrolyte provided between the second electrodes, and an electrochromic layer that develops and decolorizes between the first electrode and the second electrode in accordance with an oxidation-reduction reaction. It is characterized by having at least an electrolyte layer made of the electrolyte and thermoplastic resin particles.

INDUSTRIAL APPLICABILITY According to the present invention, the conventional problems can be solved, the object can be achieved, a spacer function capable of satisfactorily holding a gap between the respective layers provided between the electrodes, and the above-mentioned layers can be satisfactorily held. It is possible to provide an electrochromic element capable of improving adhesion.

It is sectional drawing which shows typically one structural example of the electrochromic element which concerns on 1st Embodiment of this invention. It is sectional drawing which shows typically one structural example of the electrochromic element which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows typically one structural example of the electrochromic element which concerns on 3rd Embodiment of this invention. It is sectional drawing which shows typically one structural example of the electrochromic element of the prior art. It is an electron micrograph which shows the state change before and after heating of the thermoplastic resin particle used in Example 4 of this invention.

Hereinafter, the electrochromic device according to the embodiment of the present invention will be described. The electrochromic element according to the present embodiment is located between the first electrode, the second electrode facing the first electrode at a distance, and the first electrode and the second electrode. An electrochromic element having an electrolyte provided, which is an electrochromic layer between the first electrode and the second electrode, which develops and decolorizes with an oxidation-reduction reaction, and an electrolyte layer composed of the electrolyte. And at least the thermoplastic resin particles, and further, if necessary, other members.

Further, in the electrochromic device according to the embodiment of the present invention, the first electrode has a first electrochromic layer (hereinafter, referred to as "first EC layer"), and the second electrode is a second electrode. It is preferable that the electrochromic layer (hereinafter referred to as “second EC layer”) is provided, and the electrolyte is sandwiched between the first EC layer and the second EC layer. Hereinafter, each member will be described in detail.

<Thermoplastic resin particles>
The thermoplastic resin particles have a function of a spacer, have a function of keeping a constant gap (interval) between members (base materials), and contribute to improvement of adhesion between each member. Therefore, it can be used in combination with glass beads or the like used for the purpose of keeping the gap between each member constant. The size of such thermoplastic resin fine particles is not particularly limited, but for example, in the case of a spherical shape, the particle size is preferably about 1 μm to 100 μm, more preferably about 3 μm to 50 μm. For example, in order to provide a spacer function for controlling the gap of the electrolyte layer and improve the adhesion between the first EC layer, the electrolyte layer and the second EC layer, about 5 μm to 30 μm is most preferable. In this case, it is even more preferable that the particle size distribution is more uniform because fine gap control is possible. The content of the thermoplastic resin particles is not particularly limited, but is usually in the range of 1 piece / cm ^{2 to} 100,000 pieces / cm ² , preferably 10 pieces / cm ^{2 to} 100,000 pieces / cm ² .

Such thermoplastic resin particles can be obtained by a general method. As a general method, for example, a pre-prepared thermoplastic resin is subjected to various mechanical high shearing forces such as a sand mill, a ball mill having a medium, a dyno mill, a pressure discharge type disperser (Gorin homogenizer, manufactured by Gorin), and a rotary shear type homogenizer. It can be obtained by a shear emulsification method in which the mixture is dispersed in an aqueous medium, a phase inversion emulsification method in which a thermoplastic resin is dissolved in an organic solvent and then the aqueous medium is added to invert the phase. Among these, a method of polymerizing an ethylenically unsaturated compound to a desired particle size is preferable from the viewpoint of the particle size distribution of the obtained particles described above.

In the present embodiment, the ethylenically unsaturated compound is a compound having at least one ethylenically unsaturated bond, and may be a monomer having an ethylenically unsaturated bond. Examples of the ethylenically unsaturated compound include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, lauryl acrylate, and 2-ethylhexyl acrylate. , (Meth) acrylic acid esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; ethylenically unsaturated such as acrylonitrile and methacrylic acid. Saturated nitriles; ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone; Preferable examples include olefins such as isoprene, butene and butadiene, and β-carboxyethyl acrylate.

<First electrochromic layer (first EC layer) on the first electrode side>
The first EC layer is formed on the first electrode and contains, for example, an electrochromic material that is colored by a reduction reaction, and further contains other components if necessary. As the electrochromic material, either an inorganic electrochromic compound or an organic electrochromic compound may be used. Further, a conductive polymer known to exhibit electrochromism can also be used. As the first EC layer, it is preferable to use a structure in which an organic electrochromic compound is supported on conductive or semiconductor fine particles. Specifically, for example, a structure in which fine particles having a particle size of about 5 nm to 100 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. The structure efficiently injects electrons into the organic EC compound by utilizing the large surface effect of the fine particles, and therefore responds at a higher speed than the conventional electrochromic device. Further, since a transparent film can be formed as the first EC layer by using the fine particles, a high color density of the electrochromic dye can be obtained. It should be noted that a plurality of types of organic electrochromic compounds can also be supported on conductive or semiconductor fine particles.

Examples of the electrochromic material include polymer-based or dye-based electrochromic compounds. Specifically, for example, azobenzene-based, anthraquinone-based, diarylethene-based, dihydroprene-based, dipyridine-based, styryl-based, styrylspiropirane-based, spiroxazine-based, spirothiopyrane-based, thioindigo-based, tetrathiafluvalene-based, terephthalic acid-based, tri Low molecules such as phenylmethane, triphenylamine, naphthopyrane, viologen, pyrazoline, phenazine, phenylenediamine, phenoxazine, phenothiazine, phthalocyanine, fluorane, flugide, benzopyran, metallocene, etc. Examples thereof include based organic electrochromic compounds, conductive polymer compounds such as polyaniline and polythiophene. These may be used alone or in combination of two or more. Among these, a viologen-based compound or a dipyridine-based compound is preferable from the viewpoint of having a low bleaching potential and showing a good color value.

Examples of the viologen-based compound include the compounds described in Japanese Patent No. 3955641, JP-A-2007-171781, and JP-A-2008-116718. Among these, the dipyridine compound represented by the following general formula (1) is preferable from the viewpoint of showing a good color value for color development.

[General formula (1)]

In the general formula (1), R1 and R2 each independently represent an alkyl group or an aryl group having 1 to 8 carbon atoms which may have a substituent, and at least one of R1 and R2 is COOH. It has a substituent selected from PO (OH) ₂ and Si (OC _k H _{2k + 1} ) ₃ (where k represents 1 to 20). In the general formula (1), X represents a monovalent anion. Examples of the anion of the monovalent, not particularly limited as long as it forms a cation and stably pairs can be appropriately selected depending on the intended purpose, e.g., Br ion (Br ^-), Cl ions (Cl ^- ), ClO ₄ ion (ClO ₄ ^-), PF ₆ ion (PF ₆ ^-), BF ₄ ion (BF ₄ ^-), and the like. In the general formula (1), n, m, and 1 represent 0, 1 or 2. A, B, and C represent an alkyl group having 1 to 20 carbon atoms, an aryl group, or a heterocyclic group, each of which may have a substituent independently.

The thickness of the first EC layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.2 μm to 10.0 μm. If the thickness is less than 0.2 μm, it may be difficult to obtain the color development density, and if it exceeds 10.0 μm, the manufacturing cost may increase and the visibility may be easily lowered due to coloring.

<Second electrochromic layer (second EC layer) on the second electrode side>
The second EC layer contains, for example, an electrochromic material that is colored by an oxidation reaction. As the electrochromic material, a radically polymerizable compound having a triarylamine is contained. Further, the second EC layer may contain another radically polymerizable compound containing no polymerization initiator or triarylamine as an electrochromic material, and may further contain other components as needed. Is.

<< Radical Polymerizable Compound with Triarylamine >>
The radically polymerizable compound having a triarylamine is important for imparting an electrochromic function having a redox reaction on the surface of the second electrode. Examples of the radically polymerizable compound having a triarylamine include a compound represented by the following general formula 1.
[General formula 1]
An-Bm
However, when n = 2, m is 0, and when n = 1, m is 0 or 1. At least one of A and B has a radically polymerizable functional group. The A has a structure represented by the following general formula 2, and is bonded to the B at any position from R ₁ to R ₁₅ . The B has a structure represented by the following general formula 3, and is coupled to the A at any position from R ₁₆ to R ₂₁ .

[General formula 2]

[General formula 3]
However, in the general formulas 2 and 3, R ₁ to R ₂₁ are all monovalent organic groups, which may be the same or different, and at least one of the monovalent organic groups. Is a radically polymerizable functional group.

− Monovalent organic group −
The monovalent organic group in the general formula 2 and the general formula 3 may independently have a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxyl group, and a substituent. An alkoxycarbonyl group, an aryloxycarbonyl group which may have a substituent, an alkylcarbonyl group which may have a substituent, an arylcarbonyl group which may have a substituent, an amide group, and a substituent. It may have a monoalkylaminocarbonyl group which may have a substituent, a dialkylaminocarbonyl group which may have a substituent, a monoarylaminocarbonyl group which may have a substituent, and a substituent. Diarylaminocarbonyl group, sulfonic acid group, alkoxysulfonyl group which may have a substituent, aryloxysulfonyl group which may have a substituent, alkylsulfonyl group which may have a substituent, substituent. It has an arylsulfonyl group that may have a group, a sulfonamide group, a monoalkylaminosulfonyl group that may have a substituent, a dialkylaminosulfonyl group that may have a substituent, and a substituent. It may have a monoarylaminosulfonyl group which may have a substituent, a diarylaminosulfonyl group which may have a substituent, an amino group, a monoalkylamino group which may have a substituent, and a substituent. Dialkylamino group, alkyl group which may have a substituent, alkenyl group which may have a substituent, alkynyl group which may have a substituent, aryl which may have a substituent. A group, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an alkylthio group which may have a substituent, and an arylthio group which may have a substituent. , A heterocyclic group which may have a substituent and the like. Among these, an alkyl group, an alkoxyl group, a hydrogen atom, an aryl group, an aryloxy group, a halogen group, an alkenyl group and an alkynyl group are particularly preferable from the viewpoint of stable operation and photodurability.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group and the like. Examples of the aryl group include a phenyl group and a naphthyl group. Examples of the aralkyl group include a benzyl group, a phenethyl group, a naphthylmethyl group and the like. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group and the like. Examples of the aryloxy group include a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 4-methoxyphenoxy group, a 4-methylphenoxy group and the like. Examples of the heterocyclic group include carbazole, dibenzofuran, dibenzothiophene, oxadiazole, thiadiazole and the like. Examples of the substituent further substituted with the substituent include an alkyl group such as a halogen atom, a nitro group, a cyano group, a methyl group and an ethyl group, an alkoxy group such as a methoxy group and an ethoxy group, and an aryloxy such as a phenoxy group. Examples thereof include an aryl group such as a group, a phenyl group and a naphthyl group, and an aralkyl group such as a benzyl group and a phenethyl group.

-Radical polymerizable functional group-
The radically polymerizable functional group may be any group as long as it has a carbon-carbon double bond and is radically polymerizable. Examples of the radically polymerizable functional group include the 1-substituted ethylene functional group and the 1,1-substituted ethylene functional group shown below.

(1) Examples of the 1-substituted ethylene functional group include a functional group represented by the following general formula (i).

However, in the general formula (i), X ₁ is an arylene group which may have a substituent, an alkenylene group which may have a substituent, an −CO− group, an −COO− group, or −CON (R). ₁₀₀ ) -Group [R ₁₀₀ represents a hydrogen, alkyl group, aralkyl group, aryl group. ], Or -S- group.

Examples of the arylene group of the general formula (i) include a phenylene group and a naphthylene group which may have a substituent. Examples of the alkenylene group include an ethenylene group, a propenylene group, a butenylene group and the like. Examples of the alkyl group include a methyl group and an ethyl group. Examples of the aralkyl group include a benzyl group, a naphthylmethyl group, a phenethyl group and the like. Examples of the aryl group include a phenyl group and a naphthyl group.

Specific examples of the radically polymerizable functional group represented by the general formula (i) include a vinyl group, a styryl group, a 2-methyl-1,3-butadienyl group, a vinylcarbonyl group, an acryloyloxy group and an acryloylamide group. Examples include a vinyl thioether group.

(2) Examples of the 1,1-substituted ethylene functional group include a functional group represented by the following general formula (ii).

However, in the general formula (ii), Y is an alkyl group which may have a substituent, an aralkyl group which may have a substituent, an aryl group which may have a substituent, a halogen atom, or a cyano. Group, nitro group, alkoxy group, -COOR ₁₀₁ group [R ₁₀₁ may have a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, and a substituent. The aryl group, or CONR ₁₀₂ R ₁₀₃ (R ₁₀₂ and R ₁₀₃ may have a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. Represents an aryl group and may be the same or different from each other.)]. Further, X ₂ represents the same substituent, single bond, and alkylene group as X ₁ of the general formula (i). However, at least one of Y and X ₂ is an oxycarbonyl group, a cyano group, an alkenylene group, or an aromatic ring.

Examples of the aryl group of the general formula (ii) include a phenyl group and a naphthyl group. Examples of the alkyl group include a methyl group and an ethyl group.
Examples of the alkoxy group include a methoxy group and an ethoxy group.
Examples of the aralkyl group include a benzyl group, a naphthylmethyl group, a phenethyl group and the like.

Specific examples of the radically polymerizable functional group represented by the general formula (ii) include an α-acryloyloxy chloride group, a methacryloyloxy group, an α-cyanoethylene group, an α-cyanoacryloyloxy group, and an α-cyanophenylene group. , Methacryloylamino group and the like. Examples of the substituent further substituted with the substituents for X ₁ , X ₂ and Y include an alkyl group such as a halogen atom, a nitro group, a cyano group, a methyl group and an ethyl group, a methoxy group and an ethoxy group. Examples thereof include an alkoxy group such as, an aryloxy group such as a phenoxy group, an aryl group such as a phenyl group and a naphthyl group, and an aralkyl group such as a benzyl group and a phenethyl group. Among the radically polymerizable functional groups, an acryloyloxy group and a methacryloyloxy group are particularly preferable.

As the radically polymerizable compound having the triarylamine, compounds represented by the following general formulas 1-1 to 1-3 are preferably mentioned.

[General formula 1-1]

[General formula 1-2]

[General formula 1-3]
In the general formulas 1-1 to 1-3, R ₂₇ to R ₈₉ are all monovalent organic groups, which may be the same or different, and at least among the monovalent organic groups. One is a radically polymerizable functional group. Examples of the monovalent organic group and the radically polymerizable functional group include the same ones as those in the general formula 1.

Examples of the exemplary compounds represented by the general formula 1 and the general formulas 1-1 to 1-3 include those shown below. The radically polymerizable compound having the triarylamine is not limited to these.

<Example compound 1>

<Example compound 2>

<Example compound 3>

<Example compound 4>

<Example compound 5>

<Example compound 6>

<Example compound 7>

<Example compound 8>
<Example compound 9>

<Example compound 10>

<Example compound 11>

<Example compound 12>

<Example compound 13>

<Example compound 14>

<Example compound 15>

<Example compound 16>

<Example compound 17>

<Example compound 18>

<Example compound 19>

<Example compound 20>

<Example compound 21>

<Example compound 22>

<Example compound 23>

<Example compound 24>

<Example compound 25>

<Example compound 26>

<Example compound 27>

<Example compound 28>

<Example compound 29>

<Example compound 30>

<Example compound 31>

<Example compound 32>

<Example compound 33>

<Example compound 34>

<Example compound 35>

<Example compound 36>

<Example compound 37>

<Example compound 38>

<Example compound 39>

<Example compound 40>

<< Other radically polymerizable compounds >>
The other radically polymerizable compound is a compound having at least one radically polymerizable functional group, unlike the radically polymerizable compound having the triarylamine skeleton. Examples of the other radically polymerizable compound include a monofunctional radically polymerizable compound having one polymerizable functional group, a bifunctional radically polymerizable compound having two polymerizable functional groups, and a trifunctional compound having three or more polymerizable functional groups. Examples thereof include the above radically polymerizable compounds, functional monomers, and radically polymerizable oligomers. Among these, a radically polymerizable compound having two or more functional groups is particularly preferable. The radically polymerizable functional group in the other radically polymerizable compound is the same as the radically polymerizable functional group in the radically polymerizable compound having a triarylamine, and among these, the acryloyloxy group and the methacryloyloxy group are particularly selected. preferable.

Examples of the monofunctional radical polymerizable compound 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, styrene monomer and the like. These may be used alone or in combination of two or more.

Examples of the bifunctional radically polymerizable compound include 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, and 1, Examples thereof include 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.

Examples of the trifunctional or higher functional radical polymerizable compound include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, EO-modified trimethylolpropane triacrylate, PO-modified trimethylolpropane triacrylate, and 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, tris (acryloxy) Ethyl) isocyanurate, dipentaerythritol hexaacrylate (DPHA), caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkyl-modified dipentaerythritol pentaacrylate, alkyl-modified dipentaerytholtetraacrylate, alkyl-modified dipentaerythritol Examples thereof include trimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, 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 modification refers to ethylene oxy modification, and PO modification refers to propylene oxy modification.

Examples of the functional monomer include those substituted with fluorine atoms such as octafluoropentyl acrylate, 2-perfluorooctyl ethyl acrylate, 2-perfluorooctyl ethyl methacrylate, and 2-perfluoroisononyl ethyl acrylate. Acryloyl polydimethylsiloxane ethyl, methacryloyl polydimethyl siloxane ethyl, acryloyl polydimethyl siloxane propyl, acryloyl polydimethyl siloxane butyl, diacryloyl poly having a siloxane repeating unit of 20 to 70 described in JP-A-60503 and JP-A-6-45770. Examples thereof include vinyl monomers having a polysiloxane group such as dimethylsiloxane diethyl, acrylates and methacrylates. These may be used alone or in combination of two or more.

Examples of the radically polymerizable oligomer include epoxy acrylate-based oligomers, urethane acrylate-based oligomers, polyester acrylate-based oligomers, and the like.

At least one of the radical-polymerizable compound having the triarylamine and the other radical-polymerizable compound different from the radical-polymerizable compound having the triarylamine has two or more radical-polymerizable functional groups. It is preferable from the viewpoint of forming a crosslinked product. The content of the radically polymerizable compound having a triarylamine 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 can be sufficiently exhibited, the durability is good with repeated use by the applied voltage, and the color development sensitivity is good. Even if the content is 100% by mass, the electrochromic function is possible, and in this case, the color development sensitivity with respect to the thickness is the highest. On the contrary, the compatibility with the electrolyte required for the transfer of electric charge may be lowered, so that the electrical characteristics deteriorate due to the deterioration of durability due to repeated use by the applied voltage. Although it cannot be said unconditionally because the required electrical characteristics differ depending on the process used, 30% by mass or more and 90% by mass or less is more preferable in consideration of the balance between the characteristics of both color development sensitivity and repeatability.

<< Polymerization Initiator >>
The second EC layer has, as an electrochromic material, the radical-polymerizable compound having the triarylamine, the other radical-polymerizable compound different from the radical-polymerizable compound having the triarylamine, and the triarylamine. In order to efficiently proceed with the polymerization reaction of the mixture with the radically polymerizable compound, it is preferable to contain a polymerization initiator if necessary. Examples of the polymerization initiator include a thermal polymerization initiator and a photopolymerization initiator, but a photopolymerization initiator is preferable from the viewpoint of polymerization efficiency.

The thermal polymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 2,5-dimethylhexane-2,5-dihydroperoxide, dicumyl peroxide, benzoyl peroxide, t. -Butyl cumyl peroxide, 2,5-dimethyl-2,5-di (peroxybenzoyl) hexin-3, di-t-butylbeloxide, t-butylhydrobeloxide, cumenehydrobeloxide, lauroyl peroxide, etc. Peroxide-based initiators; azobisisobutyrynitrile, azobiscyclohexanecarbonitrile, methyl azobisisobutyrate, azobisisobutyramidine hydrochloride, azo-based initiators such as 4,4'-azobis-4-cyanovaleric acid, etc. Can be mentioned. These may be used alone or in combination of two or more.

The photopolymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. For example, diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-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, 1-phenyl-1,2-propanedione-2- (o) -Acetophenone-based or ketal-based photopolymerization initiators such as oxime; benzoin ether-based photopolymerization initiators such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether, benzoin isopropyl ether; benzophenone, 4-hydroxybenzophenone , O-Methyl benzoyl benzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether, acrylated benzophenone, benzophenone-based photopolymerization initiators such as 1,4-benzoylbenzene; 2-isopropylthioxanthone, 2- Examples thereof include thioxanthone-based photopolymerization initiators such as chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2,4-dichlorothioxanthone.

Examples of other photopolymerization initiators include ethylanthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, and bis (2,4,6-trimethylbenzoyl) phenyl. Phosphine oxide, bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, methylphenylglioxyester, 9,10-phenanthrene, aclysine compounds, triazine compounds, imidazole compounds, etc. Can be mentioned. These may be used alone or in combination of two or more.

It should be noted that those having a photopolymerization promoting effect can be used alone or in combination with the photopolymerization initiator. For example, triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, ethyl benzoate (2-dimethylamino), 4,4'-dimethylaminobenzophenone, and the like can be mentioned.

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, based on 100 parts by mass of the total amount of the radically polymerizable compound.

<< Other ingredients >>
The other components are not particularly limited and may be appropriately selected depending on the intended purpose. For example, fillers, solvents, plasticizers, leveling agents, sensitizers, dispersants, surfactants, antioxidants and the like can be selected. Can be mentioned.

The average thickness of the second EC layer is preferably 1 μm or more and 30 μm or less, more preferably 2 μm or more and 20 μm or less, and further preferably 4 μm or more and 15 μm or less.

<Electrolyte layer>
The electrolyte constituting the electrolyte layer is composed of a monofunctional radical polymerizable compound containing at least a hydroxyl group, a bifunctional or higher functional radical polymerizable compound, and an ionic conductive compound, and may contain a polymerization initiator. In addition, other components may be contained if necessary.

<< Ion conductive compounds >>
As the ionic conductive compound, for example, inorganic ionic salts such as alkali metal salts and alkaline earth metal salts can be used, and quaternary ammonium salts, acids and supporting salts of alkalis can be used. Specifically, LiClO ₄ , LiBF ₄ , 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, etc. Be done.

Further, as the ionic conductive compound, an ionic liquid can also be used. Among these, an organic ionic liquid is preferably used because it has a molecular structure showing the liquid in a wide temperature range including room temperature. As the molecular structure, as the cation component, for example, imidazole derivatives such as N, N-dimethylimidazole salt, N, N-methylethyl imidazole salt, N, N-methylpropyl imidazole salt; N, N-dimethylpyridinium salt, Pyridinium derivatives such as N, N-methylpropylpyridinium salt; aliphatic quaternary ammonium salts such as trimethylpropylammonium salt, trimethylhexylammonium salt and triethylhexylammonium salt can be mentioned. As the anion component, in consideration of the stability in the atmosphere, it is preferable to use containing a fluorine compound, for ^{_{example, BF 4 -, CF 3 SO}} 3 -, PF 4 -, (FSO 2) 2 ^{_{N -, (CF 3 SO 2}} ) 2 N - , and the like. As the ionic conductive compound, it is preferable to use an ionic liquid in which the cation component and the anion component are arbitrarily combined.

<< Monofunctional radically polymerizable compound containing hydroxyl group >>
The radical-polymerizable functional group of the monofunctional radical-polymerizable compound containing a hydroxyl group is the same as that of the radical-polymerizable compound having a triarylamine and other radical-polymerizable compounds not containing a triarylamine, and is acryloyloxy. Groups and methacryloyloxy groups are preferred. Examples of the monofunctional radically polymerizable compound containing a hydroxyl group include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, and 2-hydroxy-3-phenoxypropyl acrylate. 2-acryloyloxyethyl-2-hydroxyethyl-phthalic acid, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, 1,4-cyclohexanedimethanol monoacrylate, glycerin monomethacrylate, etc. Be done. These may be used alone or in combination of two or more.

<< Bifunctional or higher functional radical polymerizable compound >>
As the bifunctional or higher functional radical polymerizable compound, any one of the bifunctional radical polymerizable compound, the trifunctional or higher functional radical polymerizable compound, and the polyfunctional radical polymerizable oligomer described in the above-mentioned electrochromic composition shall be used. Can be done.

The content of the ionic conductive compound is preferably 10% by mass or more and 80% by mass or less, and more preferably 30% by mass or more and 60% by mass or less with respect to the total amount of the electrolyte. If the content is less than 10% by mass, there is a reason that sufficient ionic conductivity cannot be provided as an electrolyte. Further, if it exceeds 80% by mass, it cannot behave as a solid electrolyte having good workability.

On the other hand, the total content of the monofunctional radical-polymerizable compound containing a hydroxyl group and the radical-polymerizable compound having two or more functional groups is the opposite of the content of the ionic conductive compound, and is preferably 20% by mass or more and 90% by mass or less. More preferably, it is 40% by mass or more and 70% by mass or less. If the content is less than 20% by mass, it cannot behave as a solid electrolyte with good processability, and if the content exceeds 90% by mass, sufficient ionic conductivity cannot be provided. The content of the monofunctional radically polymerizable compound containing a hydroxyl group in the total radical polymerization compound in the electrolyte is preferably 20% by weight or more and 90% by weight or less, and more preferably 50% by weight or more and 80% by weight or less. If the content of the monofunctional radically polymerizable compound containing a hydroxyl group is less than 20% by weight, the adhesion between the electrolyte and the electrode is likely to be insufficient, and if it exceeds 90%, the amount of the bifunctional or higher functional radically polymerizable compound is small and the electrolyte strength is high. There are reasons why it is insufficient.

<< Polymerization Initiator >>
As the polymerization initiator, the polymerization initiator described in the second EC layer described above can be used. 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, based on 100 parts by mass of the total amount of the radically polymerizable compound. When the ionic conductive compound has poor solubility in a radically polymerizable compound, it may be dissolved in a small amount of solvent and mixed with the radically polymerizable compound.

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.

The electrolyte preferably has a photocurable electrolyte composition. This is because the device can be manufactured at a low temperature and in a short time as compared with the method of forming a thin film by thermal polymerization or evaporation of a solvent. The average thickness of the electrolyte layer made of the electrolyte is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 100 nm or more and 10 μm or less.

<1st electrode and 2nd electrode>
The material of the first electrode and the second electrode is not particularly limited as long as it is a conductive transparent material, and can be appropriately selected depending on the intended purpose. For example, tin-doped indium oxide ( Examples thereof include "ITO"), fluorine-doped tin oxide (hereinafter referred to as "FTO"), antimonated tin oxide (hereinafter referred to as "ATO"), and inorganic materials such as zinc oxide. Among these, InSnO, GaZnO, SnO, In ₂ O ₃ , and ZnO are preferable.

Furthermore, transparent carbon nanotubes and other highly conductive non-permeable materials such as Au, Ag, Pt, and Cu are formed in a fine network to improve conductivity while maintaining transparency. Electrodes may be used. Further, it may have a laminated structure in which conductive oxides such as ITO, conductive metals such as Au, and conductive carbons such as carbon nanotubes are laminated in layers. When ITO is used as the material for 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 to 500 nm.

As a method for producing each of the first electrode and the second electrode, for example, a vacuum vapor deposition method, a sputtering method, an ion plating method and the like can be used. There is no particular limitation as long as the materials of the first electrode and the material of the second electrode can be applied and formed, and for example, a spin coating method, a casting method, a microgravure coating method, a gravure coating method, a bar coating method, and the like. Roll coating method, 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 Various printing methods such as a printing method can be used.

<Other parts>
The other members are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a support, an insulating porous layer, a deterioration prevention layer, and a protective layer.

-Support-
The support has a function of supporting the first electrode, the first EC layer, the second electrode, the second EC layer, and the like. As the support, any transparent material that can support each layer may be used, and well-known organic glass or inorganic glass can be used as it is.

As the support, for example, a glass substrate such as non-alkali glass, borosilicate glass, float glass, and soda-lime glass can be used. Further, as the support, a resin substrate such as polycarbonate, acrylic resin, polyethylene, polyvinyl chloride, polyester, epoxy resin, melamine resin, phenol resin, polyurethane, or polyimide may be used.
Further, the surface of the base material may be coated with a transparent insulating layer, a UV cut layer, an antireflection layer or the like in order to enhance water vapor barrier property, gas barrier property, ultraviolet ray resistance, and visibility. Polycarbonate is preferably used as the support having workability and transparency.

The shape of the support is not particularly limited and may be appropriately selected depending on the intended purpose. For example, it may be rectangular or round. The support may be a plurality of superpositions, and for example, by forming a structure in which an electrochromic element is sandwiched between two glass substrates, it is possible to enhance the water vapor barrier property and the gas barrier property.

(Manufacturing method of electrochromic element)
The method for manufacturing an electrochromic element according to the present embodiment is for an electrochromic element having a first electrode, a second electrode, and an electrolyte provided between the first electrode and the second electrode. The manufacturing method preferably includes a coating step and a cross-linking step, and further includes other steps as necessary.

<Applying process>
The coating step is a step of coating the first electrochromic composition containing the above-mentioned inorganic electrochromic compound or organic electrochromic compound on the first electrode. Further, on the second electrode, a second radical-polymerizable compound having the above-mentioned triarylamine skeleton, another radical-polymerizable compound different from the radical-polymerizable compound having the triarylamine, and a filler are contained. This is a step of applying the electrochromic composition of.

A coating solution containing the first or second electrochromic composition is applied onto the first and second electrodes. The coating liquid is diluted with a solvent and applied if necessary. The solvent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, an alcohol solvent such as methanol, ethanol, propanol and butanol; a ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone. Ester solvents such as ethyl acetate and butyl acetate; Ether solvents such as tetrahydrofuran, dioxane and propyl ether; Halogen solvents such as dichloromethane, dichloroethane, trichloroethane and chlorobenzene; Aromatic solvents such as benzene, toluene and xylene; Methyl Examples thereof include cellosolve-based solvents such as cellosolve, ethyl cellosolve, and cellosolve acetate. These may be used alone or in combination of two or more. The dilution ratio with the solvent varies depending on the solubility of the first or second electrochromic composition, the coating method, the thickness of the first EC layer or the second EC layer, and the like, and can be appropriately selected. The coating can be performed by, for example, a dip coating method, a spray coating method, a bead coating method, a ring coating method, or the like.

<Crosslinking process>
The cross-linking step is a step of cross-linking the applied first and second electrochromic compositions by applying heating or light energy. After applying the first and second electrochromic compositions on the first and second electrodes, energy is applied from the outside and the mixture is cured to form the first and second EC layers. Examples of the external energy include heat, light, and radiation. The method of applying the heat energy is performed by heating from the coating surface side or the support side using air, a gas such as nitrogen, steam, various heat media, infrared rays, or electromagnetic waves.

The heating temperature is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 60 ° C. or higher and 170 ° C. or lower. As the light energy, a UV irradiation light source such as a high-pressure mercury lamp or a metal halide lamp having an emission wavelength of ultraviolet light (UV) can be mainly used, but it is visible according to the absorption wavelength of a radically polymerizable substance or a photopolymerization initiator. It is also possible to select an optical light source. Irradiation dose of UV is not particularly limited and may be appropriately selected depending on the intended purpose, 5 mW / cm ² or more 15,000 MW / cm ² or less.

<Other processes>
Examples of the other steps include a first electrode forming step, a second electrode forming step, a thermoplastic resin particle containing step, a bonding step, and the like. The first electrode forming step and the second electrode forming step can be performed by using the methods described in the first and second electrodes. Examples of the thermoplastic resin particle-containing step include a step of incorporating the thermoplastic resin particles into the electrolyte layer, a step of incorporating the thermoplastic resin particles into the first EC layer, a step of incorporating the thermoplastic resin particles into the second EC layer, and the electrolyte layer and the first EC. It is one of the steps of containing in at least one of the layer and the second EC layer. Further, it may be a step of dispersing the thermoplastic resin particles in an electrolyte containing at least an ionic liquid.

As the bonding step, for example, one having a first EC layer or the like formed on the first electrode and one having a second EC layer or the like formed on the second electrode are prepared, and a second EC layer or the like is formed on the second electrode, via an electrolyte. It can be produced by laminating these. If the electrolyte can be cured by light or heat, it can be cured after bonding.

(Electrochromic element according to the first to third embodiments)
Here, FIGS. 1 to 3 schematically show a configuration example of the electrochromic elements 100A to 100C according to the first to third embodiments of the present invention. As shown in FIGS. 1 to 3, the electrochromic elements 100A to 100C according to the first to third embodiments include a first support 1, a first electrode 2, a first EC layer 3, and an electrolyte. It includes a layer 4, a thermoplastic resin particle 5, a second EC layer 6, a second electrode 7, and a second support 8. The details of each member are as described above.

The first electrode 2 is formed on the first support 1, and the first EC layer 3 is formed on the surface of the first electrode 2. Hereinafter, these laminated bodies will be referred to as a reducing electrode side EC layer 10. The second electrode 7 is formed on the second support 8, and the second EC layer 6 is formed on the surface of the second electrode 7. Hereinafter, these laminated bodies are referred to as an oxide pole side EC layer 20. The electrolyte layer 4 is sandwiched between the first EC layer 3 and the second EC layer 6. The thermoplastic resin particles 5 also contribute to the spacer function of controlling the thickness of the electrolyte layer 4 and the improvement of the adhesion between the first EC layer 3, the electrolyte layer 4, and the second EC layer 6. The first and second EC layers 3 and 6 are decolorized in association with the electrochemical redox reaction.

In the first to third electrochromic elements 100A to 100C, the reducing electrode side EC layer 10 and the oxidizing electrode side EC layer 20 are individually prepared, and the EC layers 20 are bonded to each other via the electrolyte layer 4. Can be made.

In the electrochromic element 100A according to the first embodiment, as shown in FIG. 1, the thermoplastic resin particles 5 are contained in the electrolyte layer 4, and the thermoplastic resin particles 5 are used as spacers for adjusting the film thickness of the electrolyte layer 4. I'm using it. With this configuration, the adhesion of the × portion shown on the right side of the paper in FIG. 1 is improved. By heating to a glass transition temperature of Tg or higher after bonding, the thermoplastic resin particles 5 become transparent and the binder function is exhibited. Therefore, it is possible to improve the thickness of the electrolyte layer 4, the adhesion between the first EC layer 3 and the electrolyte layer 4 in the electrochromic element 100A, and the adhesion between the second EC layer 6 and the electrolyte layer 4.

As shown in FIG. 2, the electrochromic element 100B according to the second embodiment is shown on the right side of the paper in FIG. 2 by adding the thermoplastic resin particles 5 between the first EC layer 3 and the electrolyte layer 4. × The adhesion of the part is improved. After bonding, the thermoplastic resin particles 5 become transparent by heating to a glass transition temperature of Tg or higher, and the binder function is exhibited, so that the adhesion between the first EC layer 3 and the electrolyte layer 4 can be improved. it can.

As shown in FIG. 3, the electrochromic element 100C according to the third embodiment is shown on the right side of the paper in FIG. 3 by adding the thermoplastic resin particles 5 between the electrolyte layer 4 and the second EC layer 6. × The adhesion of the part is improved. After bonding, the thermoplastic resin particles 5 become transparent by heating to a glass transition temperature of Tg or higher, and the binder function is exhibited, so that the adhesion between the electrolyte layer 4 and the second EC layer 6 can be improved. it can.

(Conventional electrochromic element)
For comparison, FIG. 4 shows a conventional electrochromic element 100. The conventional electrochromic element 100 includes a first support 1, a first electrode 2, a first EC layer 3, an electrolyte layer 4, a thermosetting resin particle 9, a second EC layer 6, and a second. A second electrode 7 and a second support 8 are provided. The reducing electrode side EC layer 10 composed of the first support 1, the first electrode 2 and the first EC layer 3, and the oxide electrode side EC composed of the second support 8, the second electrode 7, and the second EC layer 6. The conventional electrochromic element 100 is created by individually forming the layers 20 and bonding the layers 20 to each other via the electrolyte layer 4.

In the conventional electrochromic element 100, the thermosetting resin particles 9 are used as spacers. The shape is maintained even after heat treatment (200 ° C., 30 minutes) after bonding. That is, the spacer is not transparent and can be visually recognized.

Examples of the present invention will be described below, but the present invention is not limited to these examples.

Thermoplastic resin particles A to C were prepared as in Preparation Examples 1 to 3 below. A differential scanning calorimeter DSC / RDC220 (manufactured by Seiko Instruments Inc.) was used to measure the glass transition temperature Tg of the thermoplastic resin fine particles. A Coulter Multisizer Type II (manufactured by Beckman Coulter) was used for measuring the particle size of the thermoplastic resin particles.

(Example 1 of Preparation of Thermoplastic Resin Particle A)
300 parts by weight of ion-exchanged water and 1.5 parts by weight of TTAB (tetradecyltrimethylammonium bromide, manufactured by Sigma) were placed in a separable flask, and after nitrogen substitution for 20 minutes, the temperature was raised to 65 ° C. with stirring. It was warm.

Next, 40 parts by weight of the n-butyl acrylate monomer was added, and the mixture was further stirred for 20 minutes. After dissolving 0.5 parts by weight of the polymerization initiator V-50 (2,2'-azobis (2-methylpropion amidine) dihydrochloride, manufactured by Wako Pure Chemical Industries, Ltd.) in 10 parts by weight of ion-exchanged water in advance, It was put into a flask. It was held at 65 ° C. for 3 hours, and 0.5 parts by weight of TTAB was dissolved in 61 parts by weight of styrene monomer, 9 parts by weight of n-butyl acrylate monomer, 2 parts by weight of acrylic acid and 0.8 parts by weight of dodecanethiol. The emulsified solution emulsified in 100 parts by weight of the ion-exchanged water was continuously charged into the flask over 2 hours using a metering pump. The temperature was raised to 70 ° C. and held for another 2 hours to complete the polymerization. Then, the pH in the system was adjusted to 6.0 with a 0.5 mol / liter aqueous sodium hydroxide solution, and then heated to 80 ° C. while continuing stirring.

While heating to 80 ° C., an aqueous sodium hydroxide solution was additionally added dropwise to prevent the pH from falling below 5.0. After holding at 80 ° C. for 3 hours, a part of the slurry was washed and dried by centrifugal dehydration, and it was confirmed that resin particles having a particle size of about 5 μm were generated. In addition, when DSC analysis in the temperature range of -80 ° C to 140 ° C was performed, a glass transition due to polybutyl acrylate was observed around -50 ° C, and a styrene-butyl acrylate-acrylic acid copolymer was observed around 60 ° C. A glass transition of the resin due to the copolymer, which is thought to consist of coalescence, was observed. The remaining slurry was replaced with a methanol solution before washing and drying to prepare a slurry solution of thermoplastic resin particles. The obtained slurry is designated as thermoplastic resin particles A.

(Example 2 of Preparation of Thermoplastic Resin Particle B)
The following components were placed in a hermetically sealed reaction vessel that rotates in a constant temperature water tank.
・ Ion-exchanged water: 100 parts by weight ・ Polyvinyl alcohol: 6 parts by weight

The reaction vessel was gently stirred at room temperature to prepare an aqueous polyvinyl alcohol solution. To this, 80 parts by weight of styrene and 2.0 parts by weight of 2,2'-azobisisobutyronitrile previously dissolved in 20 parts by weight of nbutyl acrylate were added, and the mixture was stirred with a homogenizer and then slowly constant. The suspension polymerization was completed by heating at 65 ° C. for 6 hours while stirring at the stirring speed of. After centrifugal dehydration, it was washed with water and dried to obtain a slurry liquid by the same method as in the case of Preparation Example 1 of thermoplastic resin particles. The particle size at this time was about 20 μm. In addition, when DSC analysis was performed, a glass transition of the resin due to a copolymer thought to be composed of a styrene-butyl acrylate-acrylic acid copolymer was observed at around 67 ° C. The obtained slurry is designated as thermoplastic resin particles B.

(Preparation of Thermoplastic Resin Particle C 3)
The following components were placed in a hermetically sealed reaction vessel that rotates in a constant temperature water tank.
-Methanol: 100 parts by weight-Methyl vinyl ether-maleic acid copolymer: 5 parts by weight

The reaction vessel was gently stirred at 60 ° C., and the methyl vinyl ether-maleic acid copolymer was completely dissolved in about 2 hours to prepare a dispersion stabilizer. 250 parts by weight of a methanol solution in which the dispersion stabilizer for the resin material was dissolved was transferred into a hermetically sealed reaction vessel rotating in a constant temperature water bath, cooled to room temperature, and then charged with the following components.
-Styrene: 80 parts by weight-n-Butyl acrylate: 20 parts by weight

Air was completely expelled by blowing N ₂ gas into the reaction vessel while mixing by rotating the reaction vessel, and the vessel was sealed. After that, the water tank was kept at 60 ° C., and the polymerization was carried out while stirring at 100 rpm. At this time, 2.0 parts by weight of 2,2'-azobisisobutyronitrile was used as an initiator to initiate polymerization. After 3 hours from the start of the polymerization, 1.0 part by weight of dodecyl mercaptan was diluted with 30 parts by weight of methanol and added to the polymerization system in about 30 minutes. The polymerization rate at this time was 22% as a result of measurement by the internal standard method by gas chromatography. Further polymerization was continued and the polymerization was completed in 24 hours.

After completion of the polymerization, a slurry liquid of thermoplastic resin particles C having a particle size of about 5 μm was obtained by the same method as in Preparation Examples 1 and 2. The obtained slurry is designated as thermoplastic resin particles C. When the thermoplastic resin particles C were subjected to DSC analysis, a glass transition of the resin due to the copolymer considered to be composed of a styrene-butyl acrylate-acrylic acid copolymer was observed at around 62 ° C.

(Example 1)
An example of manufacturing the electrochromic device of Example 1 is shown below. As the first and second supports and the first and second electrodes, a polycarbonate substrate with ITO (50 mm × 50 mm, thickness 0.5 mm, ITO film thickness of about 100 nm) was used. For the formation of the first EC layer and the second EC layer described below, the first and second electrodes were surface-treated with oxygen plasma before use.

<Formation of EC layer on the reducing electrode side>
Titanium oxide nanoparticle dispersion (trade name: SP210, manufactured by Showa Titanium Co., Ltd., average particle size: about 20 nm) on polycarbonate with ITO as the first electrode treated with oxygen plasma to form the EC layer on the reducing electrode side. ) Was applied by the spin coating method. Next, an annealing treatment was performed at 120 ° C. for 5 minutes to form a nanostructured semiconductor material composed of a porous titanium oxide film having a thickness of about 1.0 μm.

Next, as an electrochromic compound, a 2,2,3,3-tetrafluoropropanol solution containing 1.5% by weight of the compound represented by the following structural formula A is applied by a spin coating method, and then 120 ° C. × 10 The first EC layer was formed by adsorbing the porous titanium oxide film by annealing for a minute. Then, the first electrode of 50 mm × 50 mm was punched out at 4 kN by a press machine (manufactured by Tester Sangyo Co., Ltd.) using a Thomson blade of 40 mm × 10 mm. As a result, four 40 mm × 10 mm size reducing electrode side EC layers were obtained per 50 mm × 50 mm sheet.

<Structural formula A>

The above-mentioned thermoplastic resin particles A were applied onto the first EC layer of the obtained reducing electrode side EC layer by a spin coating method, and vacuum-dried for a whole day and night.

<Formation of EC layer on the oxidation electrode side>
In order to form the EC layer on the oxidation electrode side, an electrochromic composition having the composition shown below was prepared.
[composition]
-Triarylamine compound having a monofunctional acrylate (exemplified compound 35): 70 parts by weight-PEG400 diacrylate having a bifunctional acrylate (hereinafter referred to as "PEG400DA", manufactured by Nippon Kayaku Co., Ltd.): 30 parts by weight-IRGACURE184 (BASF) Made by Japan Co., Ltd.): 5 parts by weight ・ Methyl ethyl ketone: 900 parts by weight

Next, the obtained electrochromic composition was applied by a spin coating method on a polycarbonate with ITO as a second electrode treated with oxygen plasma. The obtained coating film was irradiated with UV having a wavelength of 250 nm at 10 mW / cm ² for 60 seconds with a UV irradiation device (SPOT CURE manufactured by Ushio, Inc.), and annealed at 60 ° C. for 4 minutes to obtain an average thickness of 1 A 0.0 μm crosslinked second EC layer was formed. Similar to the EC layer on the reducing electrode side, a Thomson blade was used and punched with a press machine (manufactured by Tester Sangyo Co., Ltd.) at 4 kN. As a result, four 40 mm × 10 mm size EC layers on the oxide electrode side were obtained per 50 mm × 50 mm sheet.

<Formation of electrolyte layer>
In order to form the electrolyte layer, an electrolyte solution having the composition shown below was prepared.
[composition]
-PEG400DA (manufactured by Nippon Kayaku Co., Ltd.): 50 parts by mass-IRGACURE184 (manufactured by BASF Japan Co., Ltd.): 2 parts by mass-1-ethyl-3-methylimidazolium bis (fluorosulfonyl) imide (manufactured by Kanto Chemical Co., Inc.): 50 parts by mass

15 μL of the obtained electrolyte solution was measured with a micropipette and dropped onto the first EC layer of the oxidation electrode side EC layer. On top of this, the reducing electrode side EC layer on which the thermoplastic resin fine particles A were sprayed was laminated with a shift of 5 mm so that the lead-out portion of the electrode was present. The obtained bonding element was annealed on a hot plate at 60 ° C. for 5 minutes, and UV with a wavelength of 250 nm was irradiated at 10 mW / cm ² for 60 seconds by a UV irradiation device (SPOT CURE manufactured by Ushio Electric Co., Ltd.). , 120 ° C. for 10 minutes to prepare the electrochromic device of Example 1. The following evaluation experiments were performed on the obtained electrochromic device of Example 1.

<Color release drive>
The color development and decolorization of the prepared electrochromic device of Example 1 was confirmed. Specifically, when a voltage of + 3V was applied for 5 seconds between the extraction portion of the first electrode of the reducing electrode side EC layer and the extraction portion of the second electrode of the oxidation electrode side EC layer, the first In the overlapping portion of the electrode 1 and the second electrode, blackish color development derived from the first EC layer and the second EC layer was confirmed.

Next, when a voltage of -3V was applied for 5 seconds between the extraction portion of the first electrode of the reducing electrode side EC layer and the extraction portion of the second electrode of the oxide electrode side EC layer, the reduction It was confirmed that the overlapping portion of the first electrode of the polar EC layer and the second electrode of the oxide polar EC layer was decolorized and became transparent.

<Adhesion evaluation>
Further, the electrode pair of the obtained electrochromic element of Example 1 was partially peeled off by a cutter, and both electrodes having a polycarbonate substrate as a support were bent at 90 °. A film chuck (FC-21, manufactured by Imada Co., Ltd.) was attached to the bent electrode, one side was attached to the digital force gauge, and the adhesion force when the film was slowly lifted from the other side and peeled off was measured with the digital force gauge. The adhesion was 1.5 N / cm, showing good adhesion.

(Comparative Example 1)
The electrochromic device of Comparative Example 1 was produced in the same manner as in Example 1 without using the thermoplastic resin particles A used in Example 1. The color development and decolorization of the obtained electrochromic element of Comparative Example 1 was confirmed in the same manner as in Example 1. Subsequently, when the adhesion force was measured in the same manner as in Example 1, the adhesion force was 0.2 N / cm, and the adhesion was poor.

(Comparative Example 2)
In place of the thermoplastic resin particles A used in Example 1, highly crosslinked polymer fine particles having a particle size of about 30 μm (Micropearl GS-230 manufactured by Sekisui Chemical Industry Co., Ltd.) were used and compared in the same manner as in Example 1. 2 electrochromic elements were manufactured. The color development and decolorization of the obtained electrochromic element of Comparative Example 2 was confirmed in the same manner as in Example 1. However, when the adhesion was measured in the same manner as in Example 1, the adhesion was 0.2 N / cm, and the adhesion was poor.

(Example 2)
The micropearl GS-230 used in Comparative Example 2 and the thermoplastic resin particles A used in Example 1 were used in combination to prepare an electrochromic device of Example 2. The color development and decolorization of the obtained electrochromic element of Example 2 was confirmed in the same manner as in Example 1. Subsequently, when the adhesion force was measured in the same manner as in Example 1, the adhesion force was 1.5 N / cm, and the adhesion was good.

(Example 3)
Instead of the thermoplastic resin particles A used in Example 1, the thermoplastic resin particles B were used to prepare the electrochromic device of Example 3 in the same manner as in Example 1. The color development and decolorization of the obtained electrochromic element of Example 3 was confirmed in the same manner as in Example 1. Subsequently, when the adhesion force was measured in the same manner as in Example 1, the adhesion force was 1.5 N / cm, and the adhesion was good.

(Example 4)
Instead of the thermoplastic resin particles A used in Example 1, the thermoplastic resin particles C were used to prepare the electrochromic device of Example 4 in the same manner as in Example 1. The color development and decolorization of the obtained electrochromic element of Example 4 was confirmed in the same manner as in Example 1. Subsequently, when the adhesion force was measured in the same manner as in Example 1, the adhesion force was 1.7 N / cm, and the adhesion was good.

Here, before and after heating, the thermoplastic resin particles C used in Example 4 were placed on a slide glass as an observation sample, a cover glass was placed on the slide glass, and the mixture was allowed to stand on a hot plate at 200 ° C. for 5 minutes. The state change was observed with an electron microscope. “Photo 1” and “Photo 1-1” in FIG. 5 show the state before heating. “Photo 1” shows a state in which the thermoplastic resin particles C are placed on a slide glass and a cover glass is placed on the slide glass, and it can be seen that the thermoplastic resin particles C are in a white fine particle state. Further, from "Photo 1-1", it can be seen that the thermoplastic resin particles C before heating are in the form of particles of about 5 μm.

“Photo 2” and “Photo 2-2” in FIG. 5 show the state after heating, and it was observed that the thermoplastic resin particles C were plasticized and became transparent by heating. Further, the thermoplastic resin particles C after heating and the cover glass were in close contact with each other, and the cover glass did not fall even when the slide glass was turned upside down.

From the above evaluation results, by using the compositions of Examples 1 to 4, good gap control and adhesion between the layers can be maintained, so that an electrochromic device having excellent repeatability and responsiveness can be provided. be able to.

Examples of aspects of the present invention are as follows.
<1> An electro having a first electrode, a second electrode facing the first electrode at a distance, and an electrolyte provided between the first electrode and the second electrode. A chromic element, between the first electrode and the second electrode, an electrochromic layer that develops and decolorizes in response to an oxidation-reduction reaction, an electrolyte layer made of the electrolyte, and thermoplastic resin particles. It is an electrochromic element characterized by having at least.
<2> The electrochromic device according to <1>, wherein the thermoplastic resin particles are contained in the electrolyte layer.
<3> The electrochromic device according to <1>, wherein the electrochromic layer is provided on the first electrode, and the thermoplastic resin particles are contained in the electrochromic layer.
<4> The electrochromic device according to <1>, wherein the electrochromic layer is provided on the second electrode, and the thermoplastic resin particles are contained in the electrochromic layer.
<5> The electrochromic layer has a first electrochromic layer provided on the first electrode and a second electrochromic layer provided on the second electrode, and the heat. The electrochromic element according to <1>, wherein the plastic resin particles are contained in at least one of the electrolyte layer, the first electrochromic layer, and the second electrochromic layer.
<6> The electrochromic device according to any one of <1>, <2> or <5>, wherein the thermoplastic resin particles are dispersed in the electrolyte containing at least an ionic liquid.
<7> The electrochromic device according to any one of <1> to <6>, wherein the thermoplastic resin particles have a particle size of 1 μm to 100 μm.

2 1st electrode 3 1st electrochromic layer (1st EC layer)
4 Electrolyte layer (electrolyte) 5 Thermoplastic resin particles 6 Second electrochromic layer (second EC layer)
7 Second electrode 100A, 100B, 100C Electrochromic element

Japanese Unexamined Patent Publication No. 62-15223 Japanese Unexamined Patent Publication No. 03-08921 Japanese Unexamined Patent Publication No. 06-281969 Japanese Patent No. 4360663 Japanese Unexamined Patent Publication No. 2004-029432 Japanese Unexamined Patent Publication No. 2006-071997 Japanese Patent No. 5338436

Claims (5)

An electrochromic device having a first electrode, a second electrode facing the first electrode at a distance, and an electrolyte provided between the first electrode and the second electrode. There,
An electrochromic layer that develops and decolorizes with a redox reaction between the first electrode and the second electrode,
It has at least an electrolyte layer made of the electrolyte and thermoplastic resin particles.
The thermoplastic resin particles are contained in the electrolyte layer,
The electrochromic layer is provided on the first electrode.
The thermoplastic resin particles are contained in the electrochromic layer,
The thermoplastic resin particles, by heating above the glass transition temperature Tg, characteristics and to Rue recto runner electrochromic device that has an a transparent nature. The electrochromic layer is provided on the second electrode.
The electrochromic device according to claim 1, wherein the thermoplastic resin particles are contained in the electrochromic layer. The electrochromic layer has a first electrochromic layer provided on the first electrode and a second electrochromic layer provided on the second electrode.
The electrochromic device according to claim 1, wherein the thermoplastic resin particles are contained in at least one of the electrolyte layer, the first electrochromic layer, and the second electrochromic layer. The electrochromic element according to any one of claims 1 to 3, wherein the thermoplastic resin particles are dispersed in the electrolyte containing at least an ionic liquid. The electrochromic device according to any one of claims 1 to 4, wherein the thermoplastic resin particles have a particle size of 1 μm to 100 μm.