JPH0336528A - Electrochromic element and production thereof - Google Patents

Abstract

PURPOSE:To efficiently produce the electrochromic (EC) element having a large contact area and a high response speed with easy operations by dispersing or solubilizing an EC material by a surfactant and forming the EC layer of the EC element by a so-called micell electrolysis method. CONSTITUTION:The EC element is basically constituted of a transparent electrode/EC layer/electrolyte layer/counter electrode. The transparent electrode is formed on a transparent substrate at need. The EC layer is formed by subjecting a dispersion or solubilizing soln., which is obtd. by dispersing or solubilizing the material of the EC layer in an aq. medium by the surfactant having 10 to 20 HLB value, to an energization treatment under the conditions of forming the thin film of the substrate on the transparent electrode. The EC layer is efficiently produced by the relatively simple operations in this way and since the EC layer is formed by the micell electrolysis method, the contact area and the response speed increase.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrochromic device and a method for manufacturing the same.
The present invention relates to an EC element having a large contact area and a fast response speed, in which an EC layer (hereinafter referred to as an EC layer) is formed by a so-called micelle electrolysis method using a specific surfactant, and an efficient manufacturing method thereof.

[Problems to be solved by conventional techniques and inventions] In recent years,
EC display panels using EC elements are CRT (Ca
It is attracting attention as one of the next generation display panels to replace the Thode Ray Tube. Conventionally, this EC element has (1) used as an EC layer a thin film of an inorganic material such as tungsten dioxide deposited on an electrode substrate by a physical vapor deposition method such as a vacuum evaporation method or a sputtering method;
(2) A dye material such as viologen or pyrazoline is thinly coated on the electrode substrate and this coating is used as an EC layer, or (3) polythiophene, polypyrrole, etc. are coated on the electrode substrate by electrolytic polymerization, etc. It has been proposed that a thin film made of a conductive organic polymer is formed and used as an EC layer.

However, since these EC elements cannot have a sufficiently large contact area, they are not satisfactory in terms of response speed, contrast, etc.

Further, the conventional method for manufacturing an EC element requires complicated operations and is not necessarily efficient.

Therefore, the inventor of the present invention aimed to solve the problems of the conventional EC elements described above, develop an EC element with a large contact area and a fast response speed, and also make it possible to efficiently manufacture the EC element with simple operations. A method must be developed.We conducted extensive research.

[Means to solve the problem]

As a result, it has been found that the above object can be achieved by forming the EC layer of the EC element by a so-called micelle electrolysis method. The present invention was completed based on this knowledge.

That is, the present invention provides an EC element in which 11 EC layers are formed on a transparent electrode, and an electrolyte layer is formed between the EC layer and a counter electrode, and the EC layer is made of a material of the EC layer. By dispersing or solubilizing a dispersion or solubilizing solution in an aqueous medium with a surfactant having an HLB value of 10 to 20, the dispersion or solubilization solution is treated with electricity under conditions that form a thin film of the material on a transparent electrode. The object of the present invention is to provide an EC element characterized in that the EC element is formed by forming the EC element. The present invention also provides the above E
In manufacturing the C element, a dispersion or solubilization solution obtained by dispersing or solubilizing the material of the EC layer in an aqueous medium with a surfactant of HLB (tl! 10 to 20) is used to produce the C element. The present invention also provides a method for manufacturing an EC element, characterized in that the EC element is formed by applying electricity under conditions that form a thin film of the material on the transparent electrode.

The EC element of the present invention basically consists of a transparent electrode/EC layer/electrolyte layer/counter electrode, and if necessary, the transparent electrode is formed on a transparent substrate. The transparent substrate here is generally glass.

Transparent plastics (acrylic resin, polycarbonate resin, polyethylene terephthalate resin, etc.).

Quartz etc. will be used. Moreover, this transparent substrate may be provided on one electrode (transparent electrode) side, the other electrode (counter electrode) side, or both, if necessary.

Next, a transparent conductive film is usually used for the transparent electrode of the EC element of the present invention, and specifically, ITO (mixed oxide of indium oxide and tin oxide), 5nOz.

Examples include conductive metal oxides such as ZnOt, and these are usually formed into a thin film by vapor deposition, sputtering, or the like.

The EC element of the present invention has an EC layer laminated on the transparent electrode, and is characterized in that the EC layer is formed by a so-called micelle electrolysis method. Here, the micelle electrolysis method is EC
A dispersion or solubilized solution obtained by dispersing or solubilizing the layer material in an aqueous medium with a surface activity having an HLB value of 10 to 20 is applied to the transparent electrode (anode or cathode) as a film (thin film) of the material. ) refers to the method of conducting energization processing under conditions where The material of the EC layer used in this method may be any material as long as it develops color through an oxidation-reduction reaction, and various materials may be used, but it is usually tungsten oxide (WOt).
, W O3), molybdenum oxide (M o Ox,
MOOri, vanadium pentoxide (VgOs), titanium oxide (TiO2), iridium hydroxide (Ir(OH),
), rhodium oxide (RhzOs·nH,O), viologen compounds, porphyrin complex compounds (rare earths such as Ru and Pt), polytetrathiofluorene (PTTF), and indigo dyes.

Suitable examples include bilene-aξ-group compounds, diindoleethenes, spiropyrans, merocyanines, and phthalocyanines and metal complexes thereof.

According to the method of the present invention, first, the material for the EC layer is dispersed or solubilized in an aqueous medium with a surfactant having an HLB value of 10 to 20 to obtain a dispersion or solubilized solution.

Here, the aqueous medium includes various media such as water, a mixture of water and alcohol, and a mixture of water and acetone.

On the other hand, as the surfactant, a surfactant having an HLB value of 10 to 20, preferably 12 to 18 is used. Preferred examples of such surfactants include nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene alkylphenyl ether, and polyoxyethylene polyoxypropylene alkyl ether. I can give it to you. In addition, it is also possible to use alkyl sulfates, polyoxyethylene alkyl ether sulfates, alkyltrimethylammonium chlorides, fatty acid diethyl 4-noethyl ξ-d, and the like. Furthermore, as a preferable example of a surfactant,
The following ferrocene derivatives may be mentioned. That is, the general formula [wherein R1 and Rz are each an alkyl group having 6 or less carbon atoms, an alkoxy group having 6 or less carbon atoms, an amino group 1 dimethylamino group, hydroxyl group, acetylamide) group, carboxyl group, methoxycarbonyl group, acetoxy group , represents an aldehyde group or a halogen, and R'' is hydrogen or has 4 carbon atoms.
~18 straight chain or branched alkyl group or alkenyl group, R4 and R5 each represent hydrogen or methyl group, Y represents oxygen or oxycarbonyl group, a is an integer of O ~ 4, b is O ~ 4 The integer 8m is an integer from 1 to 18, and n is a real number from 2.0 to 70.0. ] The ferrocene derivative represented by the following can be mentioned as a typical example. Here, each symbol in general formula (I) is as described above. In other words, international publication WO3B107
538. WO39101939゜Patent Application 1986-2337
As described in No. 97 and others, R1 and R1 each represent an alkyl group having 6 or less carbon atoms (methyl group (CH3),
ethyl group (C, Hs), etc.), alkoxy group (methoxy group (OCH:t), ethoxy group (QC!H!l), etc.), amino group (NHR), etc.

dimethylamino) group (N (CH3) z)), hydroxyl group (OH).

Acetyl group (NHCOCHs), carboxyl group (COOH), acetoxy group (OCOCH3).

Methoxycarbonyl group (COOCH3), aldehyde group (CHO) or halogen (chlorine, bromine.

fluorine, iodine, etc.). R1 and R2 may be the same or different, and even if a plurality of R1 and R2 are present in the five-membered ring of ferrocene, the plurality of substituents may be the same or different. . Further, R3 represents hydrogen or a straight chain or branched alkyl group or alkenyl group having 4 to 18 carbon atoms.

Furthermore, Y is oxygen (-〇-) or oxycarbonyl group (-
C-0-), and Ra and RS represent hydrogen or a methyl group (CH3).

Therefore, -0(CH,CH,O)iH2 -C-0(CH,CH2O), H or 1 etc.

Moreover, m represents an integer of 1 to 18. Therefore, an alkylene group having 1 to 1 B carbon atoms, such as an ethylene group or a propylene group, is interposed between the ring carbon atom and the oxygen or oxycarbonyl group. Furthermore, n indicates the number of repeats of the oxyalkylene group such as the above oxyethylene group,
It means not only integers from 2.0 to 70.0 but also real numbers including these, and indicates the average value of the repeating number of oxyalkylene groups, etc.

There are various ferrocene derivatives used in the method of the present invention in addition to those represented by the above general formula (1),
Ammonium type, pyridine type (International Publication WO3
B107538 etc.), patent application No. 63-23379
Specification No. 7, Specification No. 63-233798, Specification No. 63-
No. 248600, No. 63-248601, Japanese Patent Application No. 1-45370, No. 1-54956, No. 1-70680, No. 170681, No. 1-76498 Specification and 1-764
Examples include the ferrocene derivatives described in No. 99.

These ferrocene derivatives can very efficiently solubilize or disperse the material of the EC layer in an aqueous medium.

In the present invention, there are various methods for preparing the micelle solution or dispersion, but specifically, various surfactants including the ferrocene derivative of the general formula (1) are added to the aqueous medium at a concentration. is above the critical micelle concentration, and further E
The C layer material may be added and sufficiently dispersed using ultrasonic waves, a homogenizer, a stirrer, etc. at a liquid temperature of about 20°C-too°C to form micelles.

In the method of the present invention, a supporting salt is added as desired to the homogeneous dispersion or aqueous solution obtained in this way, and excess EC layer material is removed by centrifugation, decantation, static sedimentation, etc., depending on the situation. The resulting electrolyte is left standing or is subjected to energization treatment while being slightly stirred. In addition, the EC layer material may be added to the electrolytic solution during the energization process, or a part of the electrolytic solution is extracted from the system, and the ECJi material is added to the extracted electrolytic solution and thoroughly mixed and stirred.
.

A circulation circuit for returning this liquid to the system may also be provided.

The concentration of the EC layer material at this time may be at least the saturation concentration. The concentration of the surfactant is not particularly limited, but is usually 10 μM to 0.1 M, preferably 0.5 mM to 5 mM.
Select within the range. Further, a supporting salt (supporting electrolyte) is added as necessary to adjust the electrical conductivity of the aqueous medium. The amount of supporting salt to be added may be within a range that does not interfere with the solubilization or precipitation of the dispersed EC layer material, and is usually at a concentration of about 0 to 300 times that of the surfactant, preferably 10 to 200 times. As a guideline, the concentration should be approximately

Although it is possible to carry out current application without adding this supporting salt, in this case, a highly pure F and C layer thin film containing no supporting salt can be obtained. In addition, when using a supporting salt, the type of supporting salt is particularly limited as long as it can adjust the electrical conductivity of the aqueous medium without hindering the progress of solubilization or the deposition of the EC layer material on the electrode. There isn't.

Specifically, - Sulfates (salts of lithium, potassium, sodium, rubidium, aluminum, etc.) and acetates (lithium, potassium, sodium, rubidium, beryllium, magnesium, calcium, etc.) are widely used as supporting salts in boat fishing. , strontium, barium, aluminum, etc.).

Halide salts (salts of lithium, potassium, sodium, rubidium, calcium, magnesium, aluminum, etc.) and water-soluble oxide salts (salts of lithium, potassium, sodium, rubidium, calcium, magnesium, aluminum, etc.) are suitable.

The energization conditions in the method of the present invention may be set to such a condition that a thin film of the EC layer material is formed on the electrode being used.The energization conditions in the method of the present invention may vary depending on the situation. Although it varies, specifically the liquid temperature is room temperature to 70℃.
The energization process is performed at a constant potential or constant current, preferably at 20 to 60° C. and for 1 minute to 2 hours. In this constant potential energization process, the distance between the two poles is 0.
．． 5-10. OV, preferably set to a potential of 3.0 to 0.5■, and in the constant current energization process, the current density is set to 1 tt A/cj to 100 mA/d, preferably 100 u A/cd. It is sufficient to set it within the range of -10mA10J.

The ECC layer thus obtained may be further subjected to post-treatments such as electrical cleaning, solvent cleaning, and baking at 150 to 350'C, if necessary.

After forming the EC layer in this way, the EC element of the present invention can be obtained by forming an electrolyte layer and further a counter electrode by a conventional method. As the material of the electrolyte layer, AlzO3, solid electrolyte type,
5iOz, LiF.

CrzOz, Tag's, Zr0z, PLZT(Pb-
Examples include La-Zr-TiOx), Nafion-H, and ion exchange resins. Also, as a liquid electrolyte type, propylene carbonate + LiBFn.

Propylene carbonate + LiCl0a, γ-butyllactone + LiCfO4, γ-butyllactone + Li
Examples include BF*. When a liquid electrolyte type electrolyte is used, it is preferable to further provide and seal a substrate on the counter electrode, and it is also possible to form a dielectric thin film to form the electrolyte layer. Examples of the material for the dielectric thin film include Cr 20 z +Ta t Os.

Furthermore, the counter electrode is not particularly limited and may be the same as the electrodes mentioned above, such as carbon, gold, etc., which are commonly used.
A platinum, ITO electrode, or the like may be used. Here, this counter electrode may be formed as a thin film on a substrate such as stainless steel by vapor deposition or the like.

In this way, the EC element of the present invention comprising a transparent electrode/ECEC-type electrolyte layer/counter electrode can be manufactured.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1 0.1 g of amorphous powder of tungsten oxide (WO3) was dispersed with ultrasonic waves for 10 minutes in a solution of 2 mM surfactant dissolved in 100 d of water, and then dispersed with a stirrer for 3 days. Stir six:
. Thereafter, LiBr was added to give an electrolytic solution of 0.1 M.

Next, this electrolytic solution was subjected to constant potential electrolysis at a potential of 0.5 V using an ITO transparent electrode as an anode and platinum as a cathode, and the obtained thin film was fired at 500''C.

Furthermore, this WO,/ITO substrate was used as an anode, and the carbon/ITO substrate was used as an anode.
A platinum electrode was used as the cathode. Next, 0.1 g each of titanium oxide and tungsten oxide were added to 100 cc of a 0.1M I4□SO aqueous solution. Thereafter, 10 cc of glycerin was added and thoroughly stirred.

After that, this sulfuric acid solution is sealed between the two electrodes, and EC
It was named Element.

When a potential of 1.47 V was applied to the EC element manufactured in this manner, the color changed to blue, the response speed was 147 milliseconds, and the contrast ratio was 6:1.

Comparative Example 1 Using an ITO transparent electrode as a target, a molybdenum resistance boat containing tungsten oxide (WO,) was placed in a vacuum evaporation apparatus, energized, heated to 235°C, and evaporated at a deposition rate of 0.5 to 0.7 m. / sec, a thin film of tungsten oxide was obtained on the same ITO transparent electrode as in Example 1.

Next, an EC element was manufactured in the same manner as in Example 1, except that the tungsten oxide film created by the vacuum evaporation method was used instead of the tungsten oxide film created by the micelle electrolysis method in Example 1. The results are shown in Table 1.

Examples 2 to 4 E was carried out in the same manner as in Example 1, except that the compound shown in Table 1 was used as the EC layer and the film of Nafion-H (manufactured by DuPont) was used as the electrolyte.
A C element was manufactured. The results are shown in Table 1.

(The following is a blank space) [Effects of the Invention] As described above, the EC element of the present invention can be efficiently manufactured with relatively simple operations. Furthermore, since the EC layer is formed by micelle electrolysis, the contact area is large, the response speed is fast, and the contrast ratio is sufficiently satisfactory.

Therefore, the EC element of the present invention includes an EC display panel +
It can be effectively used in fields such as tM optical glass, variable ND filters, and optical shutters.

Claims (3)

[Claims] (1) An electrochromic element comprising an electrochromic layer laminated on a transparent electrode and an electrolyte layer formed between the electrochromic layer and a counter electrode, wherein the electrochromic layer is formed of the electrochromic layer. A dispersion or solubilized solution obtained by dispersing or solubilizing the material in an aqueous medium with a surfactant having an HLB value of 10 to 20 is treated with electricity under conditions that form a thin film of the material on a transparent electrode. An electrochromic element characterized in that it is formed by. (2) Laminating an electrochromic layer on a transparent electrode,
Further, when manufacturing an electrochromic device by forming an electrolyte layer between the electrochromic layer and the counter electrode, the electrochromic layer is prepared using a surface active material having an HLB value of 10 to 20 in an aqueous medium. Production of an electrochromic device, characterized in that it is formed by applying a current to a dispersion or solubilized solution obtained by dispersing or solubilizing it with an agent under conditions that form a thin film of the material on the transparent electrode. Method. (3) The manufacturing method according to claim 2, wherein the surfactant is a ferrocene derivative.