JPH065344B2 - Multicolor display element and multicolor display device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a display element and a device, and more specifically,
The present invention relates to a multicolor display device in which the surface of a conductive support is coated with an oxidized polymer film of aniline or a derivative thereof under constant potential, and a multicolor display device using the same.

The multicolor display element plays a very important role in information related fields such as displays for commercial advertisements and image devices.

[Technical problem to be solved by the invention]

However, as seen in the display elements using electrochromism, there are some cases in which changes in two colors are observed by regulating the potential, but those in which changes in multiple colors can be stably and repeatedly obtained Absent. The inventors of the present invention have conducted intensive studies for the purpose of developing such a polychromatic display element. As a result, they have found that the above object can be achieved by using an electrode coated with an oxidized polymer film of aniline or a derivative thereof under a constant potential, and completed the present invention.

[Structure of Invention]

The present invention provides a multicolor display device comprising a derivative support and an oxide polymer film of aniline or a derivative thereof coated under a constant potential, and the multicolor display device and the multicolor display device connected to The counter electrode is immersed in an electrolyte solution to change the potential of the multicolor display element, thereby changing the color of the oxide polymer film.

In the multicolor display device, the color of the oxide polymer film is reversibly changed by changing the potential applied to the multicolor display element.

The aniline or its derivative used in the present invention is a compound in which at least one amino group is covalently bonded to the benzene ring. Representative examples of such compounds include:
Aniline, N-methylaniline, N, N-dimethylaniline, o-, p-, or m-toluidine, o-, p
-, Or m-phenylenediamine, o-, p-, or m-aminophenol, or an N-alkyl-substituted or cyclic alkyl-substituted product of these. Most preferred is aniline.

The most preferable method for synthesizing an oxidative polymer of these compounds is an electrolytic oxidative polymerization method.

In the electrolytic oxidation polymerization method, a suitable conductive support, for example, an electrode (working electrode) such as Nesa glass, platinum or graphat is immersed in a solution such as water containing aniline or a derivative thereof and an electrolyte to prepare a counter electrode and a standard electrode (working electrode). A silver-silver chloride electrode, etc.) is used to make a triode electrolysis device, and then the working electrode is +0.2 to +5.0
By applying an electric potential (relative to the standard electrode) for 10 seconds to 2 hours, aniline or a derivative thereof is oxidatively polymerized on the working electrode to deposit an oxidized polymer film on the working electrode. The concentration of aniline or its derivatives used is 0.1
It is suitable to be 2 mol / mol. The electrolyte is not particularly limited as long as it is dissolved in a solvent and oxidation of the electrolyte does not occur during electrolytic polymerization, for example, hydrogen halide, alkali metal salt, alkaline earth metal salt, tetraalkylammonium salt, organic acid salt, A metal complex or the like is used. As the solvent, water, acetonitrile, tetrahydrofuran (T
HF), dimethylformamide (DMF), or mixtures of these are suitable. Especially aniline, o-, m
In the case of -or p-phenylenediamine, etc., water is preferable as the solvent, and a stable film can be obtained by carrying out electrolytic polymerization at a pH of 4 or less. The electrolysis condition is usually about 1V at about 1V.
It may be about 5 seconds, but when preparing a thick film, a higher potential or a longer time may be used. According to this method, the polymer film can be easily formed on the working electrode as described above. The film thickness can be easily controlled according to the purpose. The suitable thickness of the polymer film is about 100Å to 10 μm.

For example, taking aniline as an example, by electrolytic oxidation polymerization method,
The reaction formula for producing a polymer is as follows.

In order to use the oxide polymer film thus coated on the conductive support as a display element, it is immersed in an electrolyte solution, and after connecting an appropriate counter electrode, a conductive film coated with the oxide polymer film is used. The potential of the support electrode may be changed arbitrarily.

Water gives good results as a solvent for the electrolyte solution. The solution is preferably acidic, particularly pH 4 to 1. If the pH is lowered more than necessary, the oxidized polymer film is likely to be decomposed, resulting in poor color reproducibility due to repeated potential changes. Any electrolyte may be used as long as it can be dissolved in a solvent, and examples thereof include hydrogen halides, alkali metal salts, alkaline earth metal salts, tetraalkylammonium salts, organic acid salts, and metal complexes. The concentration of electrolyte is 0.00
5-4 mol / degree is suitable.

The counter electrode may be any conductive one that is inactive, such as platinum, copper, graphite, carbon,
Nesa glass, inorganic and organic semiconductors can also be used.

When the potential of the conductive support electrode coated with the oxide polymer film is strictly controlled, a standard electrode such as a silver-silver chloride electrode may be used.

〔Example〕

The present invention will be specifically described below with reference to examples. The following examples do not limit the scope of the invention.

Example 1 1 cm square smooth platinum plates were used as working and counter electrodes, silver / silver chloride electrodes were used as standard electrodes, and an aqueous solution containing 1 mol / aniline and 2 mol / hydrochloric acid was used as an electrolyte solution. The above working electrode, counter electrode and standard electrode are immersed in this and connected to a potentiostat, and the potential is + 1.00V.
Electrolytic oxidative polymerization was performed for 15 seconds (on the standard electrode) to form an aniline oxidized polymer film on the working electrode.

Next, the electrode coated with the aniline oxide polymer film prepared as described above was washed with water and used as a working electrode, together with the same counter electrode and standard electrode as described above, 0.2 mol of lithium chloride and 0.01
It was immersed in an aqueous solution containing mol / hydrochloric acid and connected to a potentiostat. Working electrode potential continuously and 0.00V
(To standard electrode, same below) first from + 0.60V-
Upon sweeping to 0.70 V at 10 mV / sec, the color of the aniline oxide polymer film changed as shown in Table 1. Such color changes were repeatedly and reversibly obtained.

Example 2 As an alternative to the smooth platinum plate of Example 1, Nesa glass (2 × 1
cm) with a white lead wire as the working electrode, and with the same counter electrode and standard electrode as in Example 1
Immerse in the same electrolyte solution as above, and set to + 0.80V (to standard electrode) 1
Electrolytic oxidative polymerization was carried out for 5 seconds to form an aniline oxidized polymer film on the Nesa glass.

In this way, an area of about 1 cm ² is covered with the aniline oxide polymer film and the NES glass electrode is dipped in an aqueous solution containing 0.2 mol / liter of lithium chloride and 0.01 mol · hydrochloric acid to form a platinum counter electrode and a silver-silver chloride electrode. It is a tripolar type using. The working electrode potential is 0.0V, -0.7V, + 0.2V, + 0.5V and + 0.7V
Each sample was maintained at V for 5 minutes and taken out, and the visible absorption spectrum was measured for each potential, and the results shown in the accompanying drawings were obtained. A shift due to the potential of the absorption band was observed over almost the entire visible light range. The transmitted light color for each potential was as shown in Table 2.

Example 3 A platinum plate coated with an oxidized polymer film of aniline obtained in exactly the same manner as in Example 1 was used as a working electrode, and a platinum counter electrode and silver.
It was immersed in a 0.01 mol / hydrochloric acid aqueous solution together with a silver chloride electrode to form a triode type.

When the working electrode potential was continuously changed from +0.60 V to -0.70 V as in Example 1, the same color change as in Example 1 was observed.

〔The invention's effect〕

According to the present invention, it is possible to obtain a multicolor display element and a multicolor display device that reversibly change color in accordance with a change in applied potential.

[Brief description of drawings]

The attached drawings are diagrams showing visible spectra at respective potentials when an electrode coated with an aniline oxidized polymer film of the present invention is used.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeshi Shimomura 12-3 Funakubocho, Fujinomiya-shi, Shizuoka Prefecture (56) References JP-A-56-67881 (JP, A) JP-A-58-219527 (JP, A) )

Claims (3)

[Claims] 1. A multicolor display device comprising a conductive support surface coated with an oxidized polymer film of aniline or a derivative thereof under a constant potential. 2. A multicolor display element comprising a conductive support surface coated with an oxidation polymer film of aniline or a derivative thereof under a constant potential, and a counter electrode connected to the multicolor display element. A multicolor display device, wherein the color of the oxide polymer film is changed by immersing it in a solution and changing the potential of the multicolor display element. 3. The multicolor display device according to claim 2, wherein the pH of the electrolyte solution is 1 to 4.