JPH08160471A - Electrochromic device - Google Patents

Abstract

PURPOSE: To provide an electrochromic device which can be easily formed into various shapes and areas, is rich in variation of colors, has good responsiveness and can be easily produced. CONSTITUTION: A single layer film is formed between a pair of electrodes 2, 4 by dispersing fine particles of inorg. amorphous oxide of two or more elements synthesized from an alkali metal alkoxide or an acetate and a metal alkoxide in a polymer binder. The obtained single layer film is used as an EC layer 3. By this method, the EC layer 3 can be formed by using such a film forming device that has a rather simple structure and adapts an inexpensive liquid layer forming method. Thus, not only the production cost is decreased but also various kinds of elements can be compounded with a desired compsn. ratio to synthesize, and this device can cope with even a flexible substrate, curved substrate or large-area substrate to increase the freedom of design. By using an amorphous fine powder, the mobility of ions in the EC layer 3 is increased, which improves the responsiveness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrochromic device applied to a display device or a light control device by utilizing color change due to an electrochromic phenomenon.

[0002]

2. Description of the Related Art Heretofore, an electrochromic device (hereinafter referred to as an ECD in the present specification) utilizing a discoloration due to an electrochromic phenomenon has attracted attention for use in a display device or a light control device. For example, an ECD comprising two layers of a polymer composite type solid electrolyte layer and a coloring layer in which an inorganic salt and a plasticizer are dispersed in a polymer is disclosed in JP-A-58-30731 and JP-A-59-135431. It is disclosed. Further, Japanese Patent Laid-Open No. 58-40531 discloses an example in which an organic solid electrolyte film is used in consideration of easiness of production, cost, etc. while improving those characteristics. Since each of these ECDs uses the vapor layer method for forming the EC layer, not only the shape and area thereof are limited, but also the two-layer structure makes the manufacturing process complicated. There was a problem called.

Therefore, in order to shorten the process, reduce the cost, improve the contrast, the responsiveness, and the number of repetitions, an ECD in which the color-developing layer and the electrolyte layer are an organic polar group monolayer film formed by plasma polymerization is disclosed in JP-A-64-46732. It is disclosed in the official gazette.

However, even with this ECD, EC
Since the plasma polymerization method, which is one of the vapor phase methods, is used when manufacturing the film, it is not possible to shorten the process sufficiently, and it is difficult to manufacture a large-area element or an element with a curvature due to equipment restrictions. The problem of being said is not solved. In addition, in the plasma polymerization method, the elements that can be used are limited, and the range of the composition ratio is also limited, so that the color of the coloring layer obtained and the color that changes are also limited. In addition, since the device is expensive, there is a problem that the cost becomes high.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the prior art as described above, and its main purpose is to easily cope with various shapes and areas and to have a wide variety of color development. Therefore, it is to provide an electrochromic device which has good responsiveness and is easy to manufacture.

[0006]

According to the present invention, the above-mentioned object is achieved by polymerizing a fine powder of an inorganic amorphous oxide of two or more elements synthesized from an alkali metal alkoxide or an acetate salt and a metal alkoxide between a pair of electrodes. It is achieved by providing an electrochromic device characterized in that a monolayer film formed by being dispersed in a binder is interposed.

[0007]

In this way, the EC layer can be formed in a relatively simple structure, and an inexpensive film forming apparatus by the liquid layer method can be used. Therefore, the manufacturing cost can be reduced. Instead, various kinds of elements can be synthesized with a desired composition ratio, and a flexible substrate, a curved substrate, a substrate with a large area, or the like can be used. Moreover, the mobility of ions in the EC layer is increased by using amorphous fine powder.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is a sectional view showing the structure of a double-sided transmission type ECD to which the present invention is applied. An EC layer 3 is sandwiched between substrates 1 and 5 made of transparent glass or resin via transparent electrodes 2 and 4. The transparent electrodes 2 and 4 are turned on / off by a switch operation (not shown).
A DC power supply 6 capable of turning off and reversing the polarity is connected. Here, the EC layer 3 develops color due to an electrochromic phenomenon and also functions as a solid electrolyte.

The manufacturing procedure of this ECD will be described. First,
An alcoholate compound solution is spin-coated on each of the substrates 1 and 5 and heat-treated to form transparent electrodes 2 and 4 by a liquid film method. Here, when the heat resistance of the substrate is low, the film may be formed by a vapor phase method such as vapor deposition that has been conventionally performed. For a substrate having a curved surface or a large area substrate, dipping (Dipp
ing), spray coating may be used.

Next, an alkoxide solution of an alkali metal such as Na, Li and K and an alkoxide solution of Si, Zr and Ti are mixed at a composition ratio of 0.33: 1 to 3: 1 and transesterified. A stock solution used for the EC layer 3 is obtained by. These raw solutions are hydrolyzed to synthesize a fine powder sol. Then, the solvent in the synthesized fine powder sol is volatilized and then dried at a temperature of 200 ° C. or lower. To the amorphous oxide fine powder obtained here, a polymer binder of 50 to 70 vol% and an appropriate amount of a solvent are added and stirred and mixed in a ball mill to obtain a slurry. The EC layer 3 is formed on the transparent electrode 2 of the substrate 1 or the transparent electrode 4 of the substrate 5 from this slurry by using a doctor blade, a baker applicator or the like.
At this time, by adjusting a doctor blade or a baker applicator, a film having a desired film thickness can be formed in a range of about 10 μm to 500 μm. For a substrate having a curved surface and a substrate having a large area, a desired film can be obtained by dipping and spray coating as described above. Then, the EC layer 3 is sandwiched between the other substrate and the ECD is formed.

As described above, by using the liquid phase method, various elements can be formed into films with various composition ratios, so that a coloring layer of many colors can be obtained. Further, it is easy to add a trace element in order to improve contrast and responsiveness. Further, since the amorphous fine powder is used, the response speed is fast. Table 1 shows examples of combinations of elements and coloring.

[0012]

[Table 1]

FIG. 2 is a modification of FIG. 1, and the structure thereof is the same as that of the reflection type ECD except that the substrate 5 of FIG. 1 is replaced with a normal electrode 7 made of a metal film, a foil, a metal plate or the like. This is the same as the above embodiment.

In this embodiment, the alkoxide solution of alkali metal such as Na, Li, K and the alkoxide solution of Si, Zr, Ti etc. are mixed, but the solution alkali metal acetate is used instead of the alkoxide of alkali metal. Even if it is used, the same effect can be obtained.

[0015]

As is apparent from the above description, according to the electrochromic device of the present invention, an inorganic amorphous oxide of two or more elements synthesized between an alkali metal alkoxide or an acetate salt and a metal alkoxide is provided between a pair of electrodes. By using a single-layer film formed by dispersing the above fine powder in a polymer binder as an EC layer, the EC layer has a relatively simple structure and is formed by an inexpensive liquid layer method. Since the equipment can be used, not only the manufacturing cost can be reduced, but also various kinds of elements can be synthesized with a desired composition ratio, and flexible substrates, curved substrates, large-area substrates, etc. can also be designed. The degree of freedom is improved. Further, by using amorphous fine powder, the mobility of ions in the EC layer is increased, so that the responsiveness is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing the structure of a double-sided transmission type ECD to which the present invention is applied.

FIG. 2 is a sectional view similar to FIG. 1, showing a structure of a single-sided transmission type ECD to which the present invention is applied.

[Explanation of symbols]

 1, 5 Substrate 2, 4 Transparent electrode 3 EC layer 6 DC power supply

Claims (1)

[Claims] 1. A compound prepared from an alkali metal alkoxide or an acetate salt and a metal alkoxide between a pair of electrodes.
An electrochromic device comprising a single-layer film formed by dispersing fine particles of an inorganic amorphous oxide containing elements or more in a polymer binder.