JPH01294788A - Electrochromic display material - Google Patents

Abstract

PURPOSE:To make it possible to perform a clear display having a high density of developed color, high display quality and a high contrast ratio by using a specified benzothiazole compound as the title display material in electrochromic display. CONSTITUTION:A benzothiazole compound of the formula [wherein X is a bivalent heterocyclic group (e.g., thiophene ring), a bivalent aromatic group (e.g., phenylene group), a conjugated double bond-containing alkenylene group or -NHNH- group and R1-2 are each H; an aIkoxyl group, a (substituted) aryl group, an alkyl group or an aralkyl group] is used as the title display material.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrochromic display material that reversibly develops and fades in color through a redox reaction upon application of voltage.

BACKGROUND OF THE INVENTION In recent years, as the living environment has become increasingly electronic, display elements for human vision have become increasingly important. Display elements in this field include light-emitting elements,
Those using cathode ray tubes, those using light emitting diodes,
Furthermore, as non-emissive type elements, those using liquid crystal elements are well known, and electrochromic elements are also known. Compared to conventional light-emitting and non-light-emitting devices, electrochromic elements: ■ They fit the eye like printed matter under normal ambient light, and do not become difficult to read due to external light.
The device has no viewing angle dependence and has vivid colors; ■The drive voltage is low at 0.5 to 5V, allowing direct drive from a unit battery; and it is compatible with IC circuits. ■Element structure Generally, it is simple, and there is no need to precisely control the distance between electrodes like in liquid crystal display.■ It is easy to make the screen larger.
■It has many advantages such as a wide operating temperature range. Therefore, various electrochromic elements have been proposed in the past, and their materials include tungsten oxide,
Inorganic substances such as iridium oxide and viologen pigments,
Various organic substances including anthraquinone dyes have been proposed. (For example, JP-A-60-51774
No. 60-55074, No. 60-99188, No. 60-115681, No. 60-223886, No. 6
0-231782, etc.) Problems to be Solved by the Invention However, the electrochromic display elements that have been proposed so far have problems with writing time, permissible range of applied voltage necessary for color development, color when decoloring, color density, usability. solvents, etc.
It did not satisfy all of the various demands and was still insufficient for practical use. Therefore, the current situation is that the emergence of new electrochromic display elements is awaited.

The present invention has been made in view of this serious situation, and its purpose is to provide a new material that can be used in electrochromic display elements.

Means for Solving the Problems The organic electrochromic display forest material of the present invention has the following formula: or -NHNH- group, R1 and R2 each represent a hydrogen atom, an alkoxy group, an optionally substituted aryl group, an alkyl group, or an aralkyl group). shall be.

The organic electrochromic display material of the present invention will be described in detail below.

In the above formula (I), X represents a divalent heterocyclic group, a divalent aromatic group, an alkenylene group having a conjugated double bond, or an -NHNH- group; can include divalent groups such as a thiophene ring, a furan ring, a virol ring, a 3-pyrroline ring, and a pyrazole ring.

Examples of the divalent aromatic group include a phenylene group, a biphenylene group, a naphthylene group, an anthrylene group, and a phenanthrylene group. The divalent aromatic group may have a substituent. Examples of the substituent include a methyl group, an ethyl group,
Alkyl groups such as propyl group, butyl group, amyl group, alkoxy groups such as methoxy group, ethoxy group, propoxy group, butoxy group, dimethylamino group, diethylamino group, dipropylamino group, dibutylamino group, ditolylamino group, dixylyl Examples include di-substituted amino groups such as an amino group, diphenylamino group, and dibenzylamino group, halogen atoms such as chlorine atom and bromine atom, hydroxy group, and carboxy group.

Furthermore, R and R2 each represent a hydrogen atom, an alkoxy group, an optionally substituted aryl group, an alkyl group, or an aralkyl group, and the substituents of the substituted aryl group include a methyl group, an ethyl group, and a propyl group. , alkyl groups such as butyl group and amyl group, alkoxy groups such as methoxy group, ethoxy group, propoxy group, butoxy group, dimethylamino group, diethylamino group, dipropylamino group, dibutylamino group, ditolylamino group, dixylylamino group ,
Examples include di-substituted amine groups such as diphenylamino group and dibenzylamino group, halogen atoms such as chlorine atom and bromine atom, hydroxy group, and carboxy group.

The above formula (I) that can be used in the present invention
The following can be listed as representative benzothiazole compounds represented by:

The benzothiazole compound of the present invention is used in a display element having the structure shown in FIG. The display element in FIG. 1 is a 5-liquid type cell, in which a transparent substrate 2 having a transparent or semi-transparent display electrode 1 and a support 4 having a counter electrode (the back side is the pole) 3 are interposed between a mylar The display electrode, which is constructed by enclosing a solution 6 containing an elm chlorochromic display material through an insulating spacer 5 such as Teflon and sealing with a seal 7, is made of a transparent electrode material such as indium oxide, tin oxide, indium tin oxide, etc. The counter electrode is made of the same material as the transparent electrode material, or a metal such as platinum, gold, or aluminum. Further, the support body is formed of a material such as glass or plastic. The solution containing the elm chlorochromic display material is prepared by dissolving the benzothiazole compound represented by formula (I) above in a suitable solvent together with a supporting electrolyte.

The benzothiazole compound represented by the above formula <I) is not limited to the so-called solution-type cell as described above, but also exhibits electrochromism when introduced into a polymer as a pendant group of a polymer compound, and can be used as a solid-state cell. Application to type cells is also possible.

Furthermore, by binding a compound of an appropriate size to the benzothiazole compound represented by formula (I) above to increase the molecular weight, it is also possible to control the permanent movement of the colored species generated on the electrode surface. .

Example Hereinafter, the present invention will be explained by examples.

Example 1 The above exemplified compounds No. 2 1 nugol and tetrabutylammonium perchlorate (TBAP) were used as a supporting electrolyte.
)0.1 nol was dissolved in N,N-dimethylacetamide 100011, and the resulting solution was filled and sealed in an electrochromic display element having the structure shown in FIG.

When a DC voltage of 2 to 5 V was applied between the display electrode 1 and the counter electrode 3 of this electrochromic display element, a red color was observed on the display electrode 1. This coloring disappears quickly by removing the applied voltage or by applying a voltage of the opposite polarity of about 1 V. Example 2 The above exemplified compound NQ3 11nol and tetrabutylammonium perchlorate ( TBAP)0
．． 1nol was dissolved in 1000 ij of acetonitrile, and the resulting solution was filled and sealed in the same manner as in Example 1, except that the resulting solution was used as an electrochromic material-containing solution.

After that, a DC voltage 1 is applied between the display 4S pole 1 and the counter electrode 3.
When ~2.5 cm was applied, a reddish-green color was observed on the display electrode 1. This coloring quickly disappeared by removing the applied voltage or by applying a voltage of about 1 inch of opposite polarity.

Implementation rIA3 The above exemplary compound NQ5111101 and 0.1nol of lithium perchlorate as a supporting electrolyte were mixed at 1000%
In addition to dissolving it in nJ of dimethylacetamide and using the resulting solution as an electrochromic material-containing solution,
It was filled and sealed in the same manner as in Example 1.

Thereafter, a DC voltage of 1 to 1 is applied between the display electrode 1 and the counter electrode 3.
When 2.5 ■ was applied, a deep green color was observed on the display electrode 1. By removing the applied voltage, or 1
By applying a voltage of reverse polarity of approximately 2, this coloring quickly disappeared.

Example 4 The above exemplary compound Na9 1 nn+ol and 0.1io1 of lithium perchlorate as a supporting electrolyte were mixed at 1000%
Filling and sealing were carried out in the same manner as in Example 1, except that the solution was dissolved in dimethylacetamide of nj and the resulting solution was used as an electrochromic material-containing solution.

Thereafter, a DC voltage of 1 to 1 is applied between the display electrode 1 and the counter electrode 3.
When 2.5 cm was applied, a red color was observed on the display electrode 1. By removing the applied voltage, or 1■
By applying a voltage of opposite polarity to a certain extent, this coloring quickly disappeared.

Effects of the Invention When the electrochromic display material of the present invention is used for an electrochromic display, it is possible to produce a display with high color density, clarity, display quality, and contrast ratio, and moreover, it becomes colorless when decolored. Or hardly any coloring.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of an electrochromic display element to which the electrochromic display material of the present invention is applied. DESCRIPTION OF SYMBOLS 1... Display electrode, 2... Transparent substrate, 3... Inner electrode, 4... Support body, 5... Insulating spacer, 6...
- Electrochromic display material-containing solution, 7... Seal. Patent applicant Tomegawa Paper Mills Co., Ltd. Agent Patent attorney Tsuyoshi Liquidbe Procedural amendment (spontaneous) August 21, 1999 Commissioner of the Japan Patent Office Yoshi 1) Moon Yi 1, Indication of case 1988 Patent Application No. 123946 2. Name of the invention Electrochromic display material 3. Relationship with the case of the person making the amendment Patent applicant address 5-15 Kyobashi-chome, Chuo-ku, Tokyo Name
Yagawa Paper Mills Co., Ltd. Representative Director and President Takao Inoue 4 Agent Address 1-8-5 Kanda Nishiki-cho, Chiyoda-ku, Tokyo 101 "Detailed Description of the Invention" column and "Drawings" 6 of the specification Contents of the amendment 1) "Example 2" in the first line of page 11 of the specification is deleted, and "Example 2" is inserted on a new line between the first and second lines of page 11 of the specification. 2) Correct the drawing as shown in the attached sheet. that's all

Claims (1)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, An electrochromic display material comprising a benzothiazole compound represented by the following formula: R_1 and R_2 each represent a hydrogen atom, an alkoxy group, an optionally substituted aryl group, an alkyl group, or an aralkyl group.