JPS61147235A - Electrochromic display element - Google Patents

Abstract

PURPOSE:To improve the life and contrast of display and to facilitate multicolor display by dissolving a specified dye and I2 in a nonaqueous org. soln. contg. a supporting electrolyte and using the obtd. soln. as electrochromic soln. CONSTITUTION:A confronting display electrode and a counter electrode are provided on two substrates, at least one of the two being transparent. An electrochromic soln. prepd. by dissolving a dye expressed by the formula I (wherein R1 and R2 are same or different lower alkyl; R3 and R4 are H or alkyl; R5 is lower alkyl; Z is 0 or S; X is H, halogen, lower alkyl, alkoxy, NO2, or SO2CH3; m is 2 or 3; n is an integer 1 or 2) and I2 in a nonaqueous org. soln. contg. a supporting electrolyte, is filled between the substrates. If at least one of the substrates is transparent, the product is useful as display element. If both are transparent, the element is used in the form of light transmitting display element instead of light reflecting display element. Transparent In2O3, SnO2, or mixtures thereof are used as the material for the display electrode 2 and counter electrode 3.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrochromic display element used as a light-receiving display for displaying numbers on calculators, watches and various meters, and displaying various types of home appliances.

The current state of development of conventional light-receiving displays can be found in, for example, [Nonemissive Electroopti].
cDisplays J, R, Kmetz (Ple
num Inc.) “Display Devices”
J, 1. Written by Pankore (Springer-Ve
rlag) etc.

Compared to liquid crystals, electrochromic displays have no viewing angle dependence, and their colors are bright and clear. As an electrochromic material, WO3 is well known as an inorganic material. Viologen is the most well-known organic substance, and other pigments such as pyrazolines and anthraquinones are also known.

The problem to be solved by the invention WO3 is that a thin film is formed on a transparent electrode by a vapor deposition method, etc., and an electrolytic film or a dielectric film is provided between the counter electrodes. .Problems with WO3 in practical use 1- In addition to the display life, there is uneven color between display segments, and the type of coloring is a single blue color. In particular, we need to make some improvements to the opposite moon phases.
There is a problem in that a reflector plate and the like must also be incorporated into the element.

Organic pigments such as viologen-based pigments mainly develop color through reduction.
When it is oxidized, it returns to its bleached state. The problem with viologen-based dyes is that they use dyes that become insolubilized in the colored state, but in that case, there is a problem with the reversibility of soluble and insoluble, and the problem is that the dissolution life is short. There is. In addition, halogen ions are involved in the reduction and oxidation reactions of these dyes, and these ions may have an adverse effect on the transparent electrode, and there are problems in that power consumption is high. As mentioned above, one of the practical problems of electrochromic display devices compared to liquid crystal display devices is display life and response speed. Unfortunately, there is a problem with multicolor display devices. WO3
Colored species d of inorganic substances such as d are single. Regarding organic dyes, the type of coloring can be easily changed by changing the structure of the dye, but there are only a few organic dyes that have good display life and response speed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an electrochromic display element that improves display life and contrast, and can easily be multicolored.

Means for Solving the Problems In order to achieve the object described above, the present invention provides an electric i. This electrochromic material is composed of an electrochromic material that exhibits decolorization, a supporting electrolyte, and a non-aqueous organic solvent that dissolves them, and this electrochromic material is a mixture of a dye as shown in formula [1] and I2. .

6.

In the formula, R,, R2 are the same or different lower alkyl groups, R
3, R4 is a hydrogen source or an alkyl group, R5 is a lower argyl group, Z is 0 or S atom, X is hydrogen or a halogen group,
Represents a lower argyl group, alkoxy group, NO2 group, or 5O2C group. m is 2 or 3; n is an integer of 1 or 2; 3; Function: The present invention uses an electrochromic solution containing a dye having the above composition to stably repeat a coloring and decoloring state and display a display with good contrast. It provides an element.

The dye represented by [1] above develops color upon oxidation.

In the decolored state, it has a light absorption peak in the ultraviolet range of 250 to 360 nm, but in the colored state, it has a light absorption peak in the visible range of 500 to 700 nm. Pigments show reactions from decoloring to coloring through electrochemical oxidation, but they also show coloring phenomena when they react with oxidizing substances. The dye represented by the formula [1] in "-" is mixed with a non-aqueous organic solvent, such as acetate (IJ).
When it is simply dissolved in a solution, it remains uncolored, but when an oxidizing substance is added to it, it develops a color. The oxidizing substance is an inorganic acid, an organic acid, or a substance with high electron acceptability. A supporting electrolyte is added to this colored solution to form an electrochromic solution, which is injected between a display electrode and a counter electrode to form a display element. When a voltage is applied so that the display electrode becomes negative with respect to the counter electrode, that is, a reduction reaction occurs on the display electrode side, a phenomenon of color development to decolorization is observed. Then, when no voltage is applied or when a reverse voltage is applied, the state changes from decoloring to coloring.

The reaction will be faster if a voltage is applied. As oxidizing substances, most of inorganic acids containing H, organic acids, rogides other than I2, and compounds containing them have a short reaction life of repeating coloring and decoloring. In other words, side reactions cause deterioration and decomposition of the dye, corrosion of the electrodes, and the like.

However, when -I2 is used, stable decolorization and color development reactions are repeated.

Dissolve the VC dye in a non-aqueous organic solvent to a concentration of 0.001 to 0.1 M/l, and add I2 and supporting electrolyte of the same concentration to 0.0 M/l.
An electrochromic bath solution is prepared by dissolving it in a concentration range of 5 to 1 M/l. Pigment structure [In formula 13, n =
When n = 1, the color develops from orange to red, and when n = 2, the color develops from purple to blue-green. The color density varies depending on the distance between the display electrode and the counter electrode, but even when this distance is used in units of 10 to 50 μm, a light absorption coefficient of 90 or more can be easily obtained in the light absorption wavelength range of one dye. When the display electrode portion is changed from a colored state to a decolored state by applying a voltage, the light absorption rate in the visible region becomes 0%. Therefore, although the display is of a negative type, very good display contrast can be obtained.

Example Embodiments of the present invention will be described below with reference to the drawings.

The basic structure of the display element used is shown in the figure. In the figure, 1 is a glass substrate, 2 is a display electrode, 3 is a counter electrode, 4 is a sealing material, 6 is a sealing material, and 6 is a displayable substance. If at least one of the substrates 1 is transparent, it can be used as a display element. If both are transparent, the display element is used as a light transmissive type rather than a light reflective type.33 display poles2. Transparent In2O is used as the electrode material for the counter electrode 3.

SnO2 or a mixture thereof is used. Sealing material 4
For this purpose, an organic resin adhesive such as epoxy resin or low melting point glass is used. For the sealing material 5, an adhesive such as epoxy resin or silicone resin of the same type as the sealing material, or a soft metal or semi-silicone is used. The displayable substance 6 does not exhibit the phenomenon of color development and fading and is composed of an organic dye, which is an electrochromic bath liquid, a supporting electrolyte, and a non-aqueous organic solvent that dissolves these.

<Example 1> 3.3- having a structural formula as shown below as an organic dye
Dimethyl-2-(P-dimethylaminostyryl)indolino[2.1-b]oxazoline was used.

CH2-CH2 This dye was dissolved in acetonitrile at a concentration of 0.03 M/β, further 0.03 M/l, and tetrabutylammonium perchloride as supporting electrolyte, 3 M/β. This solution is colored red with a light absorption peak around 55 onm. This solution was injected into a display element as shown in the figure.

At this time, the distance between the display electrode 2 and counter electrode 3 of the display element was 30 μ. The light absorption rate at 660 nm is about 98 coefficients. When a voltage is applied to the display electrode 2 so as to be negative with respect to the counter electrode 3, the state changes from coloring to decoloring, and the response speed is 5 Sec at -1.3V, -1.6V.
It was 3 sec+-1 for v and about 1000 for av.

A transition from decoloring to a coloring state is made by leaving no voltage applied or by applying a voltage opposite to that used during decolorization. The response speed at this time is 10, 2'-3sec at +1.3V, 1 at +1.5V
．． It is about 6 seconds.

It was confirmed that the display life was 1000H or more when -1.3V was applied to the display electrode in an atmosphere of 60°C.

The repeated life of decoloring and coloring is ±1.3V for 5s under the room width.
When a test was conducted by applying ec-5sec alternately, 5
×105 times or more.

<Example 2> As an organic dye, 3,3-dimethyl-2-(P-dimethylaminocinnamylidene vinylindolino[2,1-bJ oxazoline] having a structural formula as shown in [[lI] formula) was used. there was.

This dye was added to 0.03M acetonyl in the same manner as in Example 1.
/β was dissolved, and Equation 2 and the supporting electrolyte were also dissolved at the same concentration as in Example '1. This solution had a light absorption peak near 610 nm and exhibited a blue color.

When this solution was applied to a display element as shown in the figure by n people and the same characteristics as in Example 1 were measured, the following results were obtained.

0 color density 95 coefficient or more (61 onm) O response speed 1.3V 1.5V color erasure 3 Sec I Sec color development 1
．． 5sec 0.8~15sec display life 10
00H or more (below 60°C) 0 cycle life 1×10
(Room temperature) Due to the effects of the invention, the present invention has the general formula (%) (in the formula, R;, R2 is the same or different lower argyl group,
R5 and R4 are hydrogen atoms or argyl groups, R5 is a lower alkyl group, Z is an O or S atom, and X is hydrogen.

Halogen group, lower argyl group, alkoxy M, NO2
represents a group, 5o2GH, where m is 21 or 3. (n is an integer of 1 or 2) and 12 dissolved in a non-aqueous organic solution containing a supporting electrolyte are used to provide 4M of the electrochromic display element used in Eren I. Lochrominok solution and 1 to 1. It has an excellent display life and has a good contrast that displays by changing from a colored state to a colorless state, and has 41 points that can be applied to various applied display panels using a variety of dye colors. .

[Brief explanation of the drawing]

The figure is a sectional view showing the basic structure of the electrochromic display element of the present invention. 1...Glass substrate, 2...Display electrode, 3...
...Opposite electrode, 4... Seal removal, 5... Sealing 1.
J, 6...Displayable substances.

Claims (1)

[Claims] A display electrode and a counter electrode facing each other are provided on two substrates, one of which is at least transparent, and between the substrates, a dye having the general formula [1] and a supporting electrolyte I_2 are provided. An electrochromic display element characterized in that it is filled with an electrochromic solution dissolved in a non-aqueous organic solution. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [1] In the formula, R_1 and R_2 are the same or different lower alkyl groups, R_3 and R_4 are hydrogen or alkyl groups, R_5 is a lower alkyl group, Z is an O or S atom, X is hydrogen, halogen group, lower alkyl group, alkoxy group, NO_2 group, S
It represents an O_2CH_3 group, m is 2 or 3, and n is an integer of 1 or 2.