JPH0264192A - Electrochromic display element and production thereof - Google Patents

Abstract

PURPOSE:To obtain the novel title display element having long response life and improved shaping properties by using an electrochromic substance film consisting of a double bond conjugated conductive high polymer containing a specific monomer structural unit. CONSTITUTION:An electrochromic substance film consisting of a double bond conjugated conductive high polymer containing a monomer structural unit and expressed by the formula [R is 1-10C alkyl, ether, ester or amide; Q is sulfonic acid (1-5C) alkylester or carboxylic acid (1-5C) alkylester; X is N, H, O, Se or Te] is used to provide the aimed display element. Furthermore, when the above-mentioned substance film is formed on the surface of display pole, the above-mentioned high polymer is dissolved in an organic solvent and the solvent is applied to the surface of display pole and cast.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a novel electrochromic display element and a method for manufacturing the same.

(Prior Art) It is well known that in recent years, liquid crystal display elements have been put into practical use as display elements with low energy consumption 1, and are being used for various purposes. However, liquid crystal display elements have the problem of viewing angle dependence, and further have drawbacks such as poor display clarity, lack of memory performance, and inability to display large areas. In recent years, electrochromic (hereinafter abbreviated as EC) has been developed as a low-energy display element that compensates for these shortcomings, which utilizes so-called electrochromism, in which light absorption characteristics change depending on voltage application or electric current.
Display elements are being actively researched. EC materials used in EC display elements are broadly classified into inorganic materials and organic materials. As for the former, transition metal oxides represented by tungsten oxide have been mainly studied. (for example,
S, Deb, Appl, 0ptics, 5u
pp1.3.192 (19691°T, Yoshim
ura et al., Jpn, J, Appl Phys, 2
1.128 [+9821, same < 22.15H19
83)) However, in addition to color unevenness between segments, there are drawbacks such as the need for special measures for the cell structure in order to stabilize the counter electrode reaction or sharpen the display, and the fact that the display is monochromatic. On the other hand, the latter includes viologens (for example, C, Book 1, etc.).

J, Electrochem, Soc, 130.1
080 (1983), Itaya et al. Phys, C.
hem, 85.818 (19811), phthalocyanine complexes, etc. (e.g., M, M, Colson et al. J,
Electroch-ern, Soc, 126.
1490 (1979+) is known, but viologens have drawbacks such as precipitation of insoluble substances when used repeatedly. Furthermore, phthalocyanine complexes still have problems in adhesion between the deposited film and the substrate. Although organic materials have the great feature of being able to display multiple colors, they have the disadvantage of short response life due to the reasons mentioned above.

More recently, polyaniline (T, Kobaya
Shi et al., J. Electroanal, Chem.
, 161.419f191341, A, Kitan
i, etc., J, Electroanal, (:hem,
209.227 (19861), polypyrrole (E,
lJ, Gen1es et al., J, Electroanal
, Chern, 149.101 (19831),
Polythiophene (M, A. Druy et al., J. Phys.
Paris Co11oqC3,595f1983)
K, anito et al. Jpn, J, Appl, Phys
, 22L412 +19831) and the like have been studied as EC materials, but they have not yet reached the stage of practical use.

(Problems to be Solved by the Invention) Conductive polymers are generally characterized in that they can display multiple colors by controlling the applied voltage. However, the response life was short because deterioration of the interface caused the conductive polymer film to separate from the electrode substrate. For example, in the case of polyinthianaphthene, there is an experimental example in which the response life is 1.6×10' times. (1, Yash ima et al. J, Electroche
m, Soc, Electrochemical 5c
ienceand Technology 134.4
6 (19871) In addition, since conventional conductive polymers are formed into thin films by electrochemical polymerization, the conditions for the substrate are limited, and it is difficult to increase the area. There was a problem with the surface.

(Means for Solving the Problems) As a result of many years of research into EC display elements using conductive polymers, the present inventors have discovered that The system conductive polymer is
It was found that it has excellent EC properties and is soluble in organic solvents. By applying this substance from solution form to form a film, it is possible to create an EC with a long response life and improved formability.
It was discovered that a display element can be produced, leading to the present invention.

That is, the present invention provides an EC display element having a structure in which an electrolyte is interposed between a display electrode and a counter electrode, at least one of which is transparent. Using conductive polymers, E
The present invention provides an EC display element characterized in that an EC0I film is formed by dissolving C substance in an organic solvent and applying it to the surface of a display electrode on the electrolyte side.

The EC substance consists of a conjugated conductive polymer containing a monomer structural unit represented by the following general formula (1).

(In the formula, R is a linear or branched alkyl, ether, ester, or amide component having 1 to 10 carbon atoms; Q is a sulfonic acid alkyl ester or a carboxylic acid alkyl ester (however, this alkyl group is a linear or branched alkyl group having 1 to 50 carbon atoms; Alkyl), x is Ni1. S, O, Se, T
Indicates an element selected from the group consisting of e. ) 119 Specific examples of the monomer structural unit represented by formula (1) include thiophene-3-(methanesulfonic acid), thiophene-3-(2-ethanesulfonic acid), and thiophene-3-(2-ethanesulfonic acid).
3-(3-propanesulfonic acid), thiophene-3-(
4-butanesulfonic acid), thiophene-3-(2-ethane rM), thiophene-3-(3-propanoic acid), thiophene-3-(4-butanoic acid), thiophene-3-(
5-pentanoic acid), 3-thienyloxymethanesulfonic acid, 2-(3-thienyloxy)ethanesulfonic acid, 3
-(3-thienyloxy)propanesulfonic acid, 4-(
3-Thienyloxy)butanesulfonic acid, 3-thenyloxymethanesulfonic acid, 2(3-thenyloxy)ethanesulfonic acid, 3-(3-thenyloxy)propanesulfonic acid, 4-(3-thenyloxy)butanesulfonic acid, [
2-(3-thienyloxy)ethoxy]methanesulfonic acid, 2-[2-(3-thienyloxy)ethoxy]ethanesulfonic acid, 3-[2-(3-thienyloxy)
ethoxy]propanesulfonic acid, 4-[2-(3-thienyloxy)ethoxyJ-butanesulfonic acid, 3-thiophenecarboxamidomethanesulfonic acid, 2-(3-thiophenecarboxamido)ethanesulfonic acid, 3-(
Methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester of 3-thiophenecarboxamido)propanesulfonic acid, 4-(3-thiophenecarboxamido)butanesulfonic acid 1, etc.
Other complex 5M rings are virol, furan, selenophene,
Examples include tellurophenes with similar substituents.

In the monomer structural unit represented by general formula (1), R
is a linear or branched alkyl of carbon t'l 1-10,
Although it represents an ether or amide component, it is clear from the following reported examples that the compound represented by the general formula (1) containing each component is soluble in a solvent. (M, R, B
ryce et al. J, Chem, Soc,, ChemComm
on, 466 f19871) As an EC substance,
Q9 Although there is no particular limitation as long as the conjugated conductive polymer contains the monomer structure lit position represented by formula (I), it is preferable that the monomer structural unit represented by general formula (1) be 5
It is desirable to contain 0-100 mol%. Also, the general formula (
Monomer structural units other than r) include substances having a conjugated system, such as thiophene, alkylthiophene, aniline, virol, furan, and derivatives thereof.

EC substances are produced by electrochemically or chemically polymerizing a monomer structural unit represented by the general formula (B) or a mixture of this and a monomer structural unit having another conjugated system. A legal method is to electrochemically polymerize ordinary thiophene, virol, etc. (for example, 5solid 5tate communica
tions 46.389 (19831), and both the constant potential method and the constant current method are possible.

In addition, as a proper chemical method, a chemical polymerization method using ferric chloride of a 3-substituted product of thiophene (for example, Chemistry
Express l[+35 (can be done in the same way as 198611).

The EC substance obtained as above was treated with NMP and DMF.
Dissolved in an organic solvent such as or a mixture thereof,
When dropped onto a display layer with appropriate conductivity, it spreads uniformly to form a thin film. By drying this, an EC layer is formed.

In addition to a transparent conductive substrate obtained by vapor-depositing indium oxide, tin oxide, precious metals, etc. on a transparent insulator such as glass or polyester, the display electrode used in the present invention may also include a transparent conductive substrate for the counter electrode. In the case where the substrate is made transparent by using a substrate, an opaque conductive substrate made of carbon, noble metal, etc. can also be used. In this case, the EC display element will be visually viewed from the opposite pole side. In addition to those mentioned above, any substrate made of a material that is conductive and electrochemically stable can be used.

When coating the EC material of the present invention on the top of the display, the film thickness can be controlled by adjusting the concentration of the solution prepared by dissolving the EC material using an organic solvent and the coating MM. Film thickness is 0.0
3 to 30 μm, preferably 0.05 to 20 μm, more preferably o, t-toμI, and the film thickness is [1, [13
If it is less than μm, the contrast will not be clear and the value as a display element will be substantially lost. On the other hand, if it exceeds 30 μm, it is not preferable from the viewpoint of response speed.

The electrolytic solution used in the present invention is one in which a supporting electrolyte is dispersed or dissolved in a solvent. The supporting electrolyte used in the present invention is "C", filPF
Halide anions of Va group elements such as s-, SbF, -, AsF, -, SbClg- (7), BF.

Halide anions of elements of the l1la group, such as 1-
halogen anions such as Il, -1, Br-, CI-,
Anions such as perchlorate anions such as CtO, -, alkali metal ions such as Li', Na'''', K'''', R, N'' (R is a hydrocarbon group having 1 to 2 carbon atoms)
Quaternary ammonium ions such as TC, H,) 4P”
A combination of phosphonium ions and the like can be used.

As the solvent constituting the electrolytic solution, polar source protic solvents such as acetonitrile and acetone are preferable, and NMP,
Polar proticophilic solvents such as DMF cannot be used because they dissolve the EC layer.

The concentration of the electrolytic solution may be in the range of 0.001-10 mol/e, but preferably 0.1-1.0 mol/2.
The counter electrode used in the present invention is preferably an opaque electrode (carbon, noble metal, etc.) with a backing material or treated with a background color, but the present invention does not necessarily require a background material or background color treatment. As the counter electrode, it is also possible to use a transparent deuterium in which indium oxide, tin oxide, or d metal is deposited on a transparent insulator such as glass or polyester.

The distance between the EC layer and the counter electrode in the present invention varies depending on the type of solvent used, the type of supporting electrolyte, the concentration, the applied voltage value and current value during EC driving, the display area of the EC display element, etc. Although it cannot be specified as 0.05
It is preferable that it is 5 mm.

As described above, the EC display element obtained by the present invention has diversity in terms of the materials of the display electrode and the counter electrode substrate, and has a wide range of applications.

Since the EC display element of the present invention uses a conductive polymer as the EC material, multicolor display is possible. Moreover, this E
Unlike conventional conductive polymers, the C material is soluble in organic solvents, so the EC material layer can be formed by coating. The advantages of forming a film by the coating method compared to the conventional electrolytic polymerization method are as follows. First, the substrate used as the display electrode is not limited. In the case of the electrolytic polymerization method, a substrate serving as a display electrode in an EC display element is used as an anode, and an EC substance is directly polymerized and electrodeposited thereon. Therefore, the substrate is subject to certain conditions such as no elution or surface deterioration in the system during electrolytic polymerization, and sufficiently low surface resistance. In the case of coating method, EC
Since the polymerization process of the substance and the process of forming the EC layer on the top of the display are independent, the above conditions are not necessarily required.

Another point is that the response life is long. The response lifetime is generally impaired by phenomena such as interfacial deterioration between the EC layer and the substrate, ie, electrochemical deterioration of the substrate or the EC layer, and mechanical delamination between the EC layer and the substrate. It is thought that when the film is formed by the coating method, the adhesion between the EC layer and the substrate is much stronger than when using the electrolytic polymerization method, and the response life is improved because interfacial deterioration occurs.

(Effects of the Invention) The present invention enables multicolor display by using a conductive polymer as an EC material, and by forming a film by coating, the conditions of the display electrode substrate are not limited and the response life is long. An EC display element can be provided. Furthermore, since the coating method can form a uniform film over a large area, it is advantageous over the electrolytic polymerization method in terms of increasing the area. In other words, the present invention can be applied to a wide range of applications, such as large and small display elements, dimming glasses, light intensity adjustment filters, and optical switches, by adding flexibility to the display electrode substrate to the polychromatic properties of conductive polymers. Can be done.

Example 1 Poly[thiophene-3-(3-methyl propanesulfonate) 1 was synthesized and subjected to EC measurement.

0.30 mol/12 ((1:, 0.15 mol/! monomer (general formula % formula %)) dissolved in an acetonitrile solution containing H61, NClO4 was used as an electrolyte solution, and ITO glass was The working electrode and graph oil plate are used as opposite electrodes, and the polymerization temperature is -40℃.
When electrolytic polymerization was carried out while maintaining the temperature, a blue-black polymer was obtained on the ITO glass surface. After washing by immersing it in a7tonitrile, it was air-dried in a dry nitrogen atmosphere at room temperature, and then vacuum-dried. The polymer after vacuum drying has a deep red color and is treated with NMP in a dry nitrogen atmosphere.
A 0.5 wt % solution was prepared.

Next, the above solution was applied onto the ITO layer of the ITO glass serving as the display electrode substrate, and a film was dried to form a red-orange color and a thickness of IL.
An L+1 EC layer was formed. The EC display element was constructed as shown in FIG. That is, the EC layer 3 formed on the display electrode 2 was placed facing each other with a certain gap so that the EC layer 3 was on the opposite electrode 5 side, and the electrolytic solution 4 was sealed between them and sealed. The electrolyte used was an acetonitrile solution containing 10.0.50 mol/β of LiC. this! , :+2.5V
When a rectangular wave of ~-0.6 V and a period of 0.25 Hz was applied, a uniform, reversible, and fast EC response of red-blue green was observed. Figure 2 shows changes in the absorption spectrum in the visible-near infrared region. In FIG. 2, the solid line shows the spectrum before application of the rectangular wave pulse, and the dotted line shows the spectrum change every 0.5 seconds after application. The visual response speed was 0.1 to 0.2 seconds.

Further, no deterioration of the EC layer was observed even after repeating the EC response 3×10' times.

My husband! Synthesis and EC measurement of Supoly[thiophene-3-(2-ethanesulfonate methyl)] were carried out.

Monomer (in general formula (1), X=S, R-Q=C, l(,
The polymerization of the compound (5O3CH) was carried out under the same conditions as described in Example 1, and the EC display element was produced in the same manner.

The EC response was observed almost the same as in Example 1.

Furthermore, the response life and response speed were also observed in the same manner as in Example 1. FIG. 3 shows changes in the visible-near infrared absorption spectrum.

Example 3 Poly[thiophene-3-(methyl methanesulfonate) 1
The synthesis and EC measurements were carried out. Monomer (general formula (1)
The polymerization of the compound (TeX=s, R-Q=CH2SO, (:Hff)) was carried out under the same conditions as described in Example 1, and the EC display element was prepared in the same manner.

The EC response was pale red-green, and the same response speed and response life as in Example 1 were observed.

FIG. 4 shows changes in the visible-near infrared absorption spectrum.

Example 4 Poly[thiophene-3-(methyl propanesulfonate)
Synthesis and EC measurements were carried out using the chemical polymerization method described in No. 1.

A monomer (in the general formula (I), X=S, R-Q=C3+1
．． When a solution of C11 (:13) in which 115 mol/β of O (a compound of SO, CHI, etc.) was dissolved was added dropwise, a black precipitate of the polymer was immediately precipitated. This black precipitate was washed with methanol and filtered to obtain a red powder. Ta.

When an EC display element was prepared in the same manner as in Example 1 and the EC response speed and response life were observed, they were observed to be almost the same as in Example 1.

In order to examine the molecular weight of the polymer in this example, it was converted to Na salt in acetone using NaI. The results of gel permeation chromatography (hereinafter abbreviated as GPC) in an aqueous system are shown in FIG. The molecular weight was 32,000 in terms of pullulan.

1 Tanane Mawari 2 Poly [thiophene-3-(methyl ethanesulfonate)]
Synthesis by chemical polymerization method and EC measurements were carried out.

Monomer (in general formula (1), X=S, R-QC, H45O
, CHl compound) was carried out in the same manner as in Example 4, and a red powder of the polymer was obtained.The EC response life and response speed were observed to be almost the same as in Example 1. The results of GPC measurement are shown in Figure 6.The molecular weight was 41,000 in terms of pullulan.

Firstly, poly[thiophene-3-(3-ethyl propanesulfonate) 1] was synthesized and EC measurements were performed.

The synthesis and creation of the EC display element are the same as those described in Example 1. However, the seven-year-old was based on the general formula (1). The EC response was deep red-blue green, and the same response speed and response life as in Example 1 were observed.

Figure 7 shows +2.0V to -0.6V, period 0.125+1
It shows the absorption spectrum change in the visible-near infrared region when a z rectangular wave is applied. In the same figure, the solid line shows the spectrum before pulse application, and the dotted line shows the spectrum change every 0.2 seconds after pulse application.

Example 7 Poly[thiophene-3-(2-methyl ethanoate) 1 was synthesized and subjected to EC measurement.

Nanatsumer (X=S in general formula (I), R-QCJ4GO2
Polymerization of CHs compound) and preparation of an EC display element were carried out in the same manner as described in Example 1.

The EC response was red-green-blue, and the same response speed and response life as in Example 1 were observed. FIG. 8 shows changes in visible-near infrared absorption spectrum. (Shows spectrum changes under the same conditions as Example 6.)

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of an EC display element according to the present invention. Each number indicates the following. l...Transparent glass substrate, 2-...Display electrode, 3...
EC layer, 4... Electrolyte, 5... Counter electrode, 6... Sealed container, 7... Lead wire Figure 2 shows the square wave application of the visible-near infrared absorption spectrum of Example J. This shows the changes associated with. Similarly, FIG. 3 shows changes in the visible-near-infrared absorption spectrum of Example 2, FIG. 4 shows Example 3, FIG. 7 shows Example 6, and FIG. 8 shows Example 7. Second
The solid lines in Figures to Figure 4 are before application, and the dotted lines are 05 after application in numerical order.
The solid line in FIGS. 5 and 6 shows the spectrum before application, and the dotted line shows the spectrum every 0.2 seconds after application in numerical order. (However, in FIG. 4, the spectra after L5 seconds are close to each other, so the spectra after 2 sand diameters are omitted.) FIG. acid sodium)
1 is shown. FIG. 6 shows poly[thiophene-3-(
Figure 2 shows the GPC curve of sodium ethanesulfonate) J. Figure 5

Claims (1)

[Claims] 1. An electrochromic display in which an electrolyte is interposed between a display electrode and a counter electrode, at least one of which is transparent, and an electrochromic material film is formed on the surface of the display electrode on the electrolyte side. An electrochromic display element, wherein the electrochromic material film is a conjugated conductive polymer containing a monomer structural unit represented by the following general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) In the formula, R is a linear or branched alkyl having 1 to 10 carbon atoms,
Ether, ester or amide component, Q is sulfonic acid alkyl ester or carboxylic acid alkyl ester (
However, this alkyl group is a linear or branched alkyl group having 1 to 5 carbon atoms), and X represents an element selected from the group consisting of NH, S, O, Se, and Te. 2. When forming an electrochromic material film on the surface of the display electrode, by dissolving the conjugated conductive polymer containing the monomer structural unit according to claim 1 in an organic solvent and applying this solution to the surface of the display electrode. A method for manufacturing an electrochromic display element, characterized by forming a film.