JPS58189287A - Electrochromic display device - Google Patents

Abstract

PURPOSE:The titled display device developing desirable color and having high working stability which is formed by holding a soln. of a specified org. material and a supporting electrolyte between a pair of electrode substrates. CONSTITUTION:An electrochromic soln. 5 prepd. by dissolving 2,5-diphenyloxazole as an org. material capable of electrochemically reversible color development and extinction, and a supporting electrolyte such as tetra-butylammonium bromide in a solvent, such as propylen carbonate, and a porous light-scattering body 6 are packed between a glass substrate 1 on the inner surface of which a display electrode 3 is formed and a glass substrate 2 on the inner surface of which an opposed electrode 4 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an electrochromic (EC) display device (E
CD), particularly related to electrochromic display devices using organic EC materials.

Organic ECDs using organic EC materials are expected to be put into practical use due to their theoretical advantages such as multicolor capability and clear images, but they have not yet been put into practical use. The first reason for this is insufficient operational stability. Typical organic ECDs currently proposed and under development use viologen as the EC material, but ON-O which operates stably
According to our test results, the FF repeat life is about 1011 times, which is insufficient compared to the minimum practical life of 106 times.

It is said that the cause of this operational deterioration is due to the incomplete reversibility of the viologen precipitation-redissolution phenomenon accompanying color development-discoloration (ON-OFF), but the exact details are unknown. Second
The reason for this is that the display color is purple, which is unique to the viologen type, and cannot adequately meet market demands for diversification of display colors. In addition, the purple color of viologen is not necessarily suitable as a standard display color, which is one of the reasons why it is not accepted in the market.

An object of the present invention is to provide a novel organic ECD that has desirable display colors and stable operation.

The electrochromic display device of the present invention is an electrochromic display device that includes a solution in which an organic material and a supporting electrolyte that can be electrochemically reversibly colored and erased are dissolved, and a pair of electrode substrates that sandwich the solution. The method is characterized in that 2,5-diphenyloxazole is used as the organic detergent.

The present invention will be described below based on examples together with drawings. The figure is a schematic cross-sectional view showing one embodiment of the display device of the present invention. In the figure, 1.2 is a glass substrate, 3 is a display electrode made of a TTO (indium oxide) film, etc., a counter electrode is made of 411TO or Au film, etc., 5 is an EC solution in which an organic EC material and supporting electrolyte are dissolved, and 6 is a ceramic It is a porous light scattering material such as. As the organic EC@ material used in the EC solution 'fi4L5, 2.5-diphenyloxazole (2゜5-Diph@nyloxazol*
) Used at an f concentration of about 0.1 M/A', and nat-2-butylammonium bromide (TII) was used as the supporting electrolyte.
AB) cell temperature was 0.1 M/l @degree, and pyrene carbonate (PC) was used as the solvent. A voltage of 2.5 V't is applied between the display electrode 3 and the counter electrode 4 of the display device having such a configuration so that the one display electrode 3 side has negative polarity.
- When the voltage is applied □, the display surface exhibits a clear yellow color on the color background. Also, if the polarity of the voltage is reversed, the color is erased. When this device was tested for repeated color development and color decolorization, almost no electrochemical deterioration was observed even after at least 10 cycles, indicating that the EC solution containing the organic EC material has extremely high stability. found. In this way, this example 0EC
D can display yellow, which is one of the display colors generally desired by customers, and has high operational stability.

Note that the ECD according to the present invention is not limited to the above-mentioned embodiment; for example, not only TBAB but also other quaternary ammonium salts, Lewis acid salts, etc. can be used as the supporting electrolyte, and dimethylformamide or An organic solvent such as γ-butyrolactone or water can also be used, and the concentrations of the organic EC material and supporting electrolyte are not limited to the numerical values in the embodiment.

0.01 to 1 depending on electrolyte characteristics or required display performance
．． It can be selected within a range of about 0 M/l. It is also well known that the same background effect can be obtained by mixing powder such as TlO□ into the EC solution instead of the porous light scattering material in the above embodiments.

[Brief explanation of the drawing]

The figure is a schematic cross-sectional view of a display device according to an embodiment of the present invention. In the figure, 2...Glass substrate, 3...Display electrode, 4...Counter electrode, 5...EC solution, 6...Porous light scatterer. 1 patent attorney Susumu Uchihara: 1-1 4 Z

Claims (1)

[Claims] In an electrochromic display device including a solution in which an organic material capable of electrochemically reversibly coloring and decoloring and a supporting electrolyte are dissolved, and a pair of electrode substrates sandwiching the solution, 2.5-di An electrochromic display device characterized by using phenyloxazole.