JPH0220589A - Electrochromic device - Google Patents

Abstract

PURPOSE:To enable the formation of an electrochromic device exhibiting improved repetition life, response speed and color contrast by using a butadiene compd. having a particular structure as an electrochromic material of a coloring layer. CONSTITUTION:This electrochromic device is one wherein use is made of a butadiene compd. of formula 1 (wherein each of Ar1, Ar2, Ar3 and Ar4 is an unsubstd. or substd. aryl group, with the proviso that at least one thereof has a disubstd. amino group). Examples of the substituent of Ar1 to Ar4 include a halogen atom, an alkyl group, an alkoxy group and a disubstd. alkyl group. Examples of the disubstd. amino group include a dialkylamino group, a diaralkylamino group, a diarylamino group and a diallylamino group.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrochromic device suitable for display devices, and more particularly to an electrochromic device in which the electrochromic material of the coloring layer is a butadiene compound.

Note that although electrochromic devices are suitable for display elements, they are not particularly limited thereto, and can also be used for optical shutters, active filters, etc., so they are referred to as electrochromic devices in the sense that they include these.

BACKGROUND OF THE INVENTION Transition metals are well known as inorganic compounds exhibiting electrochromic properties, and research and development of Wo-based electrochromic devices has been particularly active. However, electrochromic materials made of transition metal oxides generally have a single color, and the color tone is not necessarily clear.
There are problems such as difficulty in producing full color.

Therefore, recently, electrochromic materials made of organic compounds, which are easy to design in color, have been attracting attention.

When organic compound electrochromic materials are classified based on their color development mechanism, they are divided into reversible electrodeposition type and ion implantation type. Viologen-based and anthraquinone-based dyes are known as electrochromic materials belonging to the former category. Known electrochromic materials belonging to the latter category include tetrathiafulvalene (TTF) and rare earth sifthalodianine. In addition, as a new compound exhibiting electrochromic properties, JP-A No. 60-99188
A stilbene compound is reported in the publication.

Problems to be Solved by the Invention However, in order to put organic electrochromic materials into practical use, it is necessary to solve problems such as short cycle life, slow response speed, and low contrast. It has been pointed out.

(2) Regarding the repeat life, each of the electrochromic layer, electrode, and electrolyte layer deteriorates, and the repeat life is approximately 101 times at a practical level.

If a repeat life of 10' times is achieved, the applications will expand, so the current goal is to achieve a repeat life of 101 times. Regarding the deterioration of the electrochromic layer, alkali metal ions in the electrolyte layer (regardless of whether it is liquid or solid) repeatedly enter and exit the electrochromic layer, and are captured and accumulated in the electrochromic layer, causing this deterioration. It has become clear. This results in 10
' times is the limit, and no solution has been found yet.

■As for the slow response speed, the conventional WO1 system has a slow response speed of 0.
It is known that, while the limit is 1 sandbox, it is possible to use organic electrochromic C materials up to several tens of m5ec. However, in practical use, LOmsec is generally considered to be a problem.

(2) Regarding low contrast, the color density can be increased by increasing the applied voltage. However, the repeated lifespan will be shortened and the display electrodes will deteriorate.
It is not appropriate to increase the voltage too much.

In view of the above problems, an object of the present invention is to provide an electrochromic device that can improve repeat life, response speed, contrast, etc.

Means for Solving the Problems An electrochromic device according to the present invention is constructed by sealing a solution containing an electrolyte of a butadiene compound between a transparent electrode on a transparent substrate and an electrode on another substrate, The basic characteristic of the butadiene compound is that it is a compound represented by the following maximum [I]; General formula: Good aryl group, at least one having a di-substituted amino group. ] Specific butadiene compounds used in the present invention include, but are not limited to, the following.

(Hereinafter, blank space) [12] Above - maximum [11, Ar11Ar2, Ar, ,
Examples of substituents for Ar include halogen atoms, alkyl groups, alkoxy groups, and di-substituted alkyl groups.

In particular, at least one of the substituents Ar and -Ar4 has a di-substituted amino group, and examples of the di-substituted amino group include a dialkylamino group, a dialkylamino group, a diarylamino group, and a diallylamino group.

The electrochromic device of the present invention is obtained by sealing between electrodes an electrochromic solution containing the above-mentioned compound of maximum [I] as a main component and also containing a solvent, a supporting electrolyte, and the like. In the above solution, −
maximum[! ] or other electrochromic materials.

Since the above-mentioned compound of the present invention has a particularly low ionization potential, it can develop color with a small applied voltage.

Further, examples of solvents used in the present invention include aprotic polar solvents such as dichloromethane, chloroform,
l,2-dichloroethane, acetonitrile, clobionitrile, benzonitrile, acetone, propylene carbonate, nitromethane, nitrobenzene, ethyl acetate,
Tetrahydro7ran, dioxane, pyridine, dimethyJ
Reformamide, dimethylsulfoxide, dimethylacetamide, etc. may be mentioned, which may be used alone or as a mixture, and may be mixed with water, alcohol, etc. Further, as the supporting electrolyte, a salt soluble in the solvent used is used. An example of this is LiCQoLiBF, NH,CQO,.

CCHs>*NCQ, (CzHs)*HCl2. (Cz
Hs)sNBr, (C!H5)4N CN, (C4H
I)4N CQO4, (C4H1)4N B F I(
Ca HI) 4 N HS OiAgCQO4,AgB
F, etc. can be mentioned.

FIG. 1 is a schematic cross-sectional view of the electrochromic device of the present invention when it is implemented as a display element.

In the figure, (1) and (2) are glass substrates, (3) is a transparent electrode, (4) is a counter electrode, (5) is an electrochromic solution in which the organic electrochromic material and supporting salt are dissolved, and (6) is It is a porous light scatterer.

The glass substrate is not particularly limited as long as it is transparent. In Figure 1, we will explain using a glass substrate, which has a suitable strength, can form a transparent electrode on its surface, and is not affected by the adverse effects such as swelling and turbidity due to the solvent used in the organic electrochromic solution. In combination, transparent resins such as polyethylene, polypropylene,
It is also possible to use polyether sulfones, polyether ether ketones, etc.

As the transparent electrode formed on the glass substrate, known ones can be applied, such as indium oxide, tin oxide,
Vapor-deposited gold, aluminum, copper, silver, etc.
? It can be formed by means such as taring. At that time, the desired translucency is ensured.

rT has a transparent electrode formed on a glass substrate.
o. Commercially available products such as NESA may also be used.

One set of transparent electrodes is connected to each electrode with a suitable lead wire such as nichrome wire, gold wire, copper wire, platinum wire, etc., and a backing is applied so that a display part of a desired shape is formed between both transparent electrodes. .

The backing material is suitably a material that is not affected by the electrolyte solution, such as Teflon tape, adhesive, or Teflon rubber.

It is desirable that the distance between the two electrodes is as small as possible without short circuiting, but if the distance becomes large, there is a possibility that the contrast in the color change will be worse.

The space formed between both electrodes is filled with a solution in which an electrochromic material such as the butadiene compound of the present invention and a supporting electrolyte are dissolved.

The concentration of electrochromic material is 0°01-1
．． 0mo(2/(2, preferably 0.05-0.5mo
It is Q/Q. l, Omo(Darker than 2/12, the fading response becomes slow, and if it is thinner than 0.01moQ/2, the change is small and clear colors are not produced.

The concentration of the supporting electrolyte is adjusted depending on the solvent used and the required display performance, but it is 0. O1~1, 0 m
It is better to set it as oO,/Q.

A porous light scattering material may be enclosed between both electrodes. As such a light scattering body, a thin ceramic plate such as alumina or silica, or a thin polymer plate can be used, and this has the effect of making the contrast of color change clearer.

As described above, when the electrochromic device of the present invention is used as a display element, there is a gap between the two electrodes.
About 3 to 4.0V, preferably about 0.5 to 3.0V,
More preferably, it can be applied at a low voltage of about 0.5 to 2.0 V, and it is thought that color development and decolorization occur when the electrochromic material present in the solution near the surface of the positive electrode undergoes redox. If the applied voltage is lower than 0.5V, color change is unlikely to occur; 4. Even if it is higher than Ov, deterioration tends to occur.

Example 1 Compound No. 4 exemplified above and NH, CQO.

NESA
An electrochromic display device was fabricated by inserting it between pieces of glass with a 1.5 μm mylar spacer interposed therebetween. The solution was slightly yellowish but transparent. When a DC voltage of 1°5V was applied to both electrodes of the resulting device, the device colored dark green, and when the voltage was removed, it returned to its original transparent state.

Next, when a voltage of 3V was applied to both electrodes of the element, there was no change other than the color becoming darker, and when the voltage was turned off, it returned to its original transparency.

From the above results, it can be seen that the electrochromic display element of the present invention exhibits good discoloration at low applied voltages and has a wide applied voltage range.

Using the display device obtained in this example, color development and decolorization were performed by turning on and off the application of a voltage of 1.5 V. Even after repeating this operation 106 times, no electrochemical deterioration occurred. It was hardly recognized.

Example 2 An engineered left-throchromic display element was produced in the same manner as in Example 1, except that compound No. 7 was used instead of compound No. 4 exemplified above.

The obtained device was operated in the same manner as in Example 1 and its characteristics were repeatedly evaluated, and results similar to those obtained with the electrochromic display device of Example 1 were obtained.

Examples 3 to 5 Electrochromic display was performed in the same manner as in Example 1, except that the compounds No. 5, No. 19, No. 11 exemplified above were used instead of the compound No. 094 used in Example 1. The device was fabricated.

The obtained device was operated in the same manner as in Example 1 and its characteristics were repeatedly evaluated, and results similar to those obtained with the electrochromic display device of Example 1 were obtained.

Effects of the Invention The electrochromic display element of the present invention has the advantage of having a high color density, a low applied voltage necessary for coloring, and a wide applied voltage range, and moreover, various solvents can be used. .

[Brief explanation of the drawing]

FIG. 1 shows a schematic cross-sectional view of an example of an electrochromic display element of the present invention. 1.2...Glass substrate, 3...Transparent electrode, 4...
Counter electrode, 5... Organic electrochromic solution, 6... Porous light scatterer. Patent applicant Minolta Camera Co., Ltd.

Claims (1)

[Claims] 1. An electrochromic device using a butadiene compound represented by the following general formula [I]. General formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] [In the formula, Ar_1, Ar_2, Ar_3, Ar_4 are aryl groups that may have substituents, and at least one has a di-substituted amino group. . ]