JPS6078428A - Transmission type electrochromic element - Google Patents

Abstract

PURPOSE:To manufacture easily a large-sized element of high contrast by using a specified mixed valence complex which develops color in an oxidized state as the material of the 1st EC layer of a transmission type EC element and a heterocyclic conjugated polymer or a metallic oxyhydroxide as the material of the 2nd EC layer. CONSTITUTION:The 1st EC layer 3 is formed on the surface of one of electrodes 2, 2 placed opposite to each other with a sealant 4 inbetween, the 2nd EC layer 5 is formed on the counter electrode 2, and an electrolyte 6 is sealed in the space between the electrodes 2, 2 to manufacture an ECD. At least one of the electrodes 2, 2 is transparent. The 1st EC layer 3 is made of a mixed valence complex which develops color in an oxidized state. The complex is represented by a formula M1x[M2(CN)6]y (where each of M1 and M2 is a transition metal, x is 3-4, and y is 2-3). The 2nd EC layer 5 is made of a heterocyclic conjugated polymer or a metallic oxyhydroxide. The EC layers 3, 5 develop deep color at the same time when color is developed, and they are made colorless at the same time when the color is vanished, so high contrast and high display quality are attained. Since the layers 3, 5 can be formed by electrodeposition or other method without requiring a vapor depositing apparatus, a large-sized element is easily manufactured at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a transmission electrochromic device with significantly improved display quality.

Prior Art FIG. 1 is a diagram showing the structure of a conventional transmission type electrochromic display element. In Fig. 1] is a transparent substrate, 2
3 is a transparent electrode, 3 is a first electrochromic layer, is a sealant, 5 is a second electrochromic layer, and 6 is an electrolyte. Such a display element was previously proposed by the present applicant in Japanese Patent Application No. 58-29289.

The display element described in this specification has one electrochromic layer formed using the following general formula % (1) (in which Ml and M2 are transition metals, X is 3 to 4, and y is 2 to 8). ), for example, Prussian blue, and the other electrochromic layer is a metal oxide layer that develops color in a reduced state, such as tungsten oxide (WO8). According to this device, electrodeposited Prussian blue can be used as the first electrochromic layer 8, and vapor-deposited WO8 can be used as the second electrochromic layer 5, and when coloring, both electrochromic layers simultaneously develop a deep color, Since both become colorless when decolored, the purpose of obtaining high contrast can be achieved. However, as mentioned above, while the first electrochromic layer, Prussian blue, can be deposited by electrodeposition, the second electrochromic layer, WO, usually has to be deposited by vapor deposition, which requires a large size. When forming such an element, a large evaporation apparatus is required, which raises the cost of the element and makes it difficult to obtain a uniform film thickness.

So: "An iron cobalt cyano complex (patent application 1986-86
No. 570) or Prussian Blue (Patent Application No. 58-5
8751) was developed. However, in the case of the former, in such conventional transmission type elements, the thickness of the iron-cobalt-cyano complex that can be electrodeposited is limited, so when Prussian blue is used in combination, the amount of electrodeposition is also limited. It is difficult to increase the coloring density sufficiently (light transmittance 2 os), and in the latter case, there is a residue when decoloring (light transmittance 60 os).The display quality is a combination of Prussian blue and WO8. There was a problem that it was lower than that of .

DISCLOSURE OF THE INVENTION The present invention has been made in view of these conventional problems, and the second electrochemical layer is made of a heterocyclic conjugated polymer or gold oxyhydroxide PA (metal oxide hydrate, m
This was achieved by constructing the structure using oxidation agents (e.g., etal oxiae/hydroxide).

That is, in the transmission type electrochromic layer of the present invention, the first electrochromic layer develops color in an oxidized state using the following general formula % formula % () (wherein Ml and M2 are transition metals, X is 8 to 4, The second electrochromic layer is composed of a heterocyclic conjugated polymer or a metal oxyhydroxide.

In the mixed valence complex represented by the above formula (1) constituting the first electrochromic layer, Ml is iron (Fe
), @ (Ou ), chromium (cr), M2 is iron (
Preferably, the compounds are Fe), ruthenium (Ru), cobalt (co), osmium (Os), and chromium (cr), and most preferably compounds consisting of a combination in which M1 is Fe and M2 is Fe or Ru. These compounds can also be used as the first electrolyte layer in a stacked manner or as a mixture.

The mixed valence complex described above can be formed into a film by ML deposition, spin coding, dip coating, or the like.

Next, the material constituting the second electrochromic layer is
Heterocyclic conjugated polymers or metal oxyhydroxides (metal oxide hydrates). Examples of heterocyclic conjugated polymers include polypyrrole, pyrrole such as poly(2,5-thennylene), and thiophene polymers. The absorption spectrum changes and discoloration occurs when the transition absorption energy of π electrons due to double bonds and unpaired electrons changes due to oxidation or reduction. Furthermore, in metal oxyhydroxides, the d electrons are excited in the d shell in transition elements, but upon oxidation or reduction, the transition absorption energy changes, the absorption spectrum changes, and the color changes. This metal oxyhydroxide can form a film by electrodeposition.

In the display element of the present invention, in the conventional transmission type electrochromic element shown in FIG.
The electrochromic layer 5 is composed of a heterocyclic conjugated polymer or a metal oxyhydroxide, and is prepared in the same manner as conventional elements except that these layers are provided on each transparent electrode in advance. be able to. That is, a first electrochromic layer and a second electrochromic layer are made to face each other, and the electrodes 2 and 2 are held parallel to each other via a seal 4 to form a cell. An electrolyte solution may be injected into the cell through an injection port (not shown) provided for the cell, and the injection port may be sealed with epoxy resin or the like to form one electrolyte layer.

For the electrolyte layer, an ion conductive layer such as a solution of sulfuric acid, hydrochloric acid, potassium chloride, potassium perchlorate, etc. dissolved in an aqueous or organic solvent, a polymer electrolyte, an inorganic solid electrolyte, etc. is used.

Embodiments of the Invention Example 1 Prussian blue was electrodeposited as the first electrochromic layer to a thickness of 150.0 mm, and a second layer was dissolved in 0.1 mol/l, containing 1% water and desorbed. Approximately 5,000 yen from the acetonitrile solution. Using polypill electropolymerized to the thickness of A, 1 morph Na was used as the electrolyte layer.
An element having the structure shown in FIG. 1 was fabricated using propylene carbonate of cto.

As a result, the color when colored was blue (about 5% in terms of light transmittance), and the color when decolored was light brown (about 75% in light transmittance), with no residue remaining and an element with a high contrast ratio could be obtained.

Example 2 In Example 1, the materials shown in Table 1 were electrolytically polymerized instead of virol to produce an element. All of the obtained elements had no residual image and had a high contrast ratio.

Table 1 Example 8 In Example 1, as the second electrochromic layer, 0.18 mol/l of N15O,.6H80 and 0.18
% of Na0AO and 0.1 mol/! of Na2S
N was electrodeposited from a mixed solution of O4 to a thickness of about a, oooJ.
A device was prepared in the same manner except that iO(OH) was used,
It was possible to obtain an element with a high contrast ratio, which was blue (light transmittance of about 5 inches) when colored, and light gray (light transmittance of about 75 inches) when decolorized, and had no residual color.

Example 4 In Example 3, a device was fabricated by electrodepositing the materials shown in Table 2 instead of NiO(OH). In either case, it was possible to obtain an element with a high contrast ratio and no residual image.

Example 5 In Example 1, xyjl) (Ru(1) (ON > 6) was 1,
A device was produced in the same manner except that electrodeposition was performed to a thickness of 500A (1). As a result, it was possible to obtain an element with a high contrast ratio, which had a purple color (light transmittance of about 5 g) when colored and a light brown color (light transmittance of about 759 g) when decolorized, with no residual color remaining.

As described in detail, according to the present invention, the first electrochromic layer contains a mixed valence complex represented by Mix(Mg(0N)6)y, and the second electrochromic layer contains a heterocyclic conjugated system. Polymer or metal oxyhydroxide (
By using a structure using metal oxide hydrate), it is possible to fabricate devices with a large contrast ratio, improving the quality of the device, and eliminating the need for vapor deposition equipment to deposit the electrochromic layer, making it possible to fabricate large devices. This has the advantage of being easier to manufacture and cheaper.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the electrochromic device of the present invention. DESCRIPTION OF SYMBOLS 1... Transparent substrate 2... Transparent electrode 8... First electrochromic layer 4... Seal material 5... Second electrochromic layer 6... Electrolyte. Patent applicant Nissan Motor Co., Ltd.

Claims (1)

[Scope of Claims] L A first electrochromic layer is provided on the surface of one of the electrodes, at least one of which is transparent, and a second electrochromic layer is provided on the surface of the opposing electrode, In an electrochromic element in which an electrolyte is sealed between picture electrodes, the first electrochromic layer is colored in an oxidized state using the following general formula % formula % (1) (in the formula, Ml and M2 are transition gold M, x is composed of a mixed valence complex represented by 3 to 3, and y is 2 to 3), and the second electrochromic layer is composed of a heterocyclic conjugated polymer or a metal oxyhydroxide. Transmissive electrochromic device.