JPS63125592A - Electrolytic polymer and electrochromic display element using same - Google Patents

Abstract

PURPOSE:To prepare an electrochemically active electrolytic polymer suited for use as an electrochromic material which is polychromic, exhibits striking contrast, and is free from color shade and excellent in repeated use performance, by the electrolytic polymn. of a monomer comprising a particular compd. CONSTITUTION:A monomer of a compd. (A) of formula I (wherein X is O or S; m, m', n and n' are each 0-2, provided that n=2-m and n'=2-m') and an electrolyte such as salts (B) of formulae II-V and Rose Bengal are dissolved in an org. solvent (C) (e.g., acetonitrile) having a high dielectric const. and capable of well dissolving component (B), so that component (A) and component (B) concentrations are 1mmol/l-1mol/l and 0.01-1.0mol/l, respectively. In this soln., a pair of electrodes are placed. Then, a voltage is applied to perform electrolytic polymn. Thus, an electrolytic polymer in a film form is deposited on the electrode surface.

Description

[Detailed Description of the Invention] [Technical Field] The present invention provides a novel electrolytic polymer that is electrochemically active, that is, capable of doping and dedoping electrolyte ions by an electrochemical method, and a depolymer thereof. The present invention relates to an electromic display element.

[Prior art]

BACKGROUND ART Electrolytic polymerization has been known as a method for producing functional polymer compounds that are expected to have various applications as electronic materials. This electrolytic polymerization method is a method in which an electrolyte and a monomer are dissolved in water or an organic solvent, a pair of electrodes are placed in the solution, and a certain voltage is applied to deposit a polymer on the electrode surface.

Examples of polymers produced by this method include U.S. Pat. No. 3,574,072 for polypyrrole;
A,F,Diaz,et al,,rJ,C
,S.

Chem, Comm, 635 (1979) J and A, F, Diaz.

at al,, rJ, c, s, chsm, Comm
, $54 (1979) J. Kaneto, et al., on polythenylene.

rJ, c, s, Chem, Comm,, 381
(1983) J, A, F for polyteniri/
Diaz, et al., rJ.

Electroanal, Chem, 111.
111 (1980) J and T, Ohsaka,
et al,, rJ, Electroanal,
Chem.

υ, 1.399 (1984) J.

Including the above report, the monomers that have been used to produce electrochemically active polymers by electrolytic polymerization include virol, virol derivatives, thiophene, thiophene derivatives, furan, aniline, and aniline derivatives. It is limited and there are very few types.

In addition, as an electrochromic material used in a display element that utilizes the so-called electrochromic phenomenon in which the amount of light absorbed increases when an electric field is applied and recovers reversibly when the electric field is removed, WO3 is an inorganic material. It is well known, and examples of organic substances include viologen, pyrazoline, anthraquinone, and pigments of styryl-based analogue compounds. However, WO3 has practical problems in that it has a short display life, color unevenness between display segments, and the type of coloring is a single blue color. Further, there are problems in that the material for the counter electrode must be carefully selected in order to stabilize the counter electrode reaction, and a reflector or the like must also be incorporated into the element. In addition, viologen dyes develop color when reduced and return to a decolorized state when reduced, but there is a problem with this reversibility, so the display life is short. Furthermore, since ions are involved in these redox reactions, there are problems in that these ions may have an adverse effect on the transparent electrode and power consumption is large.

Therefore, there has been a demand for the development of electrochromic materials that do not have the above problems.

〔the purpose〕

The present invention was made in view of the above-mentioned current situation, and one of its objectives is to produce a new electrochemically active conjugated polymer from monomers that have not been used until now by electrolytic polymerization. It is in. Another object of the present invention is to provide a new electrochromic material that is multicolored, has high contrast, has no color unevenness, has excellent repeatability, and is very easy to manufacture.

〔composition〕

In order to achieve the above object, the present inventor has repeatedly studied various monomers, and found that the monomers have the formula (wherein, X represents ot or s'v, and m, m',
n and n' represent integers from 0 to 2, but n = J-m and n' = 2-m' must be used and electrochemically activated by electropolymerizing the compound. The present inventors have discovered that a new polymer compound can be obtained, and have completed the present invention.

The electrolytic polymer of the present invention has the formula (wherein, X% m
, m', n, and n' are as described above), the monomer and the electrolyte are dissolved in an organic solvent to form a solution, and in this solution, for example, a pair of electrodes It can be manufactured by depositing a polymer on the electrode surface by applying a voltage.

Specific examples of the compound of the above formula used as a monomer in the present invention include, but are not limited to, the following.

1H40GNH2 2H2N ((shi86NH2 9(eN001N0) The solvent used for electrolytic polymerization has a high dielectric constant and dissolves the electrolyte well, so even if two or more solvents are mixed, a small amount of water will be added. Specific examples of solvents include acetonitrile, benzonitrile, propylene carbonate, alcohol, dimethylformamide,
Examples include nitrobenzene, N-methylpyrrolidone, tetrahydrofuran, dimethylsulfoxide, and the like. These solvents are preferably distilled to remove impurities.

As the electrolyte, organic or inorganic salts or double salts, complex salts, ionic dyes, etc., which are soluble in the solvent used and easily ionically dissociated, are used. Specifically, for example (n-C4Hp
)4NctO4, (C2H5)4NBF4, (C2H5
)NH8O4, (n-C4Hp)4N-CH480g,
(C2Hs)4NPF6. Llctoa, NaA
sF6. Examples include AgBF4 and Rose Bengal. These electrolytes are preferably purified and vacuum dried before use. The concentration of the electrolyte used in the polymerization is Q, 01~tom
ot/l, preferably 0.05 to 0.3 mol.
/L range.

The fIk degree of a monomer depends on its solubility in the solvent used, but is generally used in the range of 1 mmoL/l to 1 m04/L.

In addition, if necessary, hydrogen acceptor 2 may be added as an additive.
, 6-lutidine, pyridine, 2,4,6-collidine, etc. greatly promote the production of polymers. The concentration of the additive is arbitrary, but is preferably in the range of 1/10 to 20 times the monomer.

The electrolytic polymerization reaction can be carried out by a bipolar method or a bipolar method, and potential-based polymerization, voltage-based polymerization, or current-based polymerization can be performed.

In the case of the triode method, common reference electrodes can be used, but SCE or silver/silver chloride is often used.

In the method of the present invention, polymerization can be carried out at an electrolytic voltage of 1 V or higher relative to SCE; however, constant potential, cyclic potential, or bipolar method, constant current or constant voltage may be used for polymerization. As the electrode material, ITO glass, Nesa glass, platinum plate, carbon electrode, etc. can be used as the working electrode, and platinum wire, nickel plate, etc. can be used as the counter electrode.

The electrolytic polymer produced as described above can be used as an electrochromic display element by utilizing its electrochromic phenomenon. The electrochromic phenomenon is a phenomenon in which the amount of light absorbed increases when an electric field is applied to a light transmitting material, and it recovers reversibly when the electric field is removed. The electrochroming phenomenon caused by electrolytic polymers is prominent in polypyrrole, polythenylene, polyaniline, etc.
This phenomenon is caused by changes in the electronic state in the polymer caused by doping or dedoping of dopant (dopants) such as perchlorate ions, fluoride ions, and iodine. ing.

The electrochromic display element of the present invention basically consists of an electrolytic polymer deposited on one electrode, a solvent containing a supporting electrolyte sealed between the two electrodes in a sandwich-like manner, and leads from these two electrodes. It is constructed by taking out the wire and connecting it to a power supply circuit, etc.

Note that at least one of the two electrodes must be a transparent electrode. The solvent used in the electrochromic display element has a high dielectric constant and dissolves the electrolyte well, and two or more kinds of solvents may be mixed. Specific examples of the solvent include acetonitrile, benzonitrile, propylene carbonate, alcohol, dichloromethane, chloroform, 1,2-dinolethane, acetone, nitromethane, ethyl acetate, pyridine, dihydrofuran, dioxane dimethylformamide, nitrobenzene, N -Methylpyrrolidone, dimethylsulfoxide, water, etc. Further, as the supporting electrolyte, a salt soluble in the solvent used is used. An example is LiC
'to4, LiBF4, NH4Cto4, (
CR2)4Net, (C2H5)4Net.

(C2Hs)4NBr, (C2H5)NCN,
(C2Hs)4NcZO4, (C2H5)4NBF'4
, (C4H9)4NC! 04, (C4H9)4NBF4
, (04H9)4NH8O4,AgClO4,Ag
Examples include BF4.

Next, the structure of the electrochromic display of the present invention will be explained with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing an example of an electrochromic or mink display element of the present invention, which is equipped with a transparent display electrode 2 to which the electrolytic polymer 1 of the present invention, which is an electrochromic material, is resistant to adhesion. A solvent 7 containing a supporting electrolyte is sealed between a transparent substrate 3 and a support 5 having a counter electrode (back electrode) 4 via an insulating spacer 6 such as Mylar or Teflon, and sealed with a seal 8. . As shown in FIG. 2, the electrolytic polymer 1 may be firmly attached to the counter electrode (back electrode) 4. The display electrode is made of a transparent electrode material such as indium oxide, tin oxide, or indium tin oxide, and 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 made of a material such as glass or plastic.

Examples are shown below to further specifically explain the present invention, but the present invention is not limited thereto.

Example 1 Tetra-n- as an electrolyte in 20 m of acetonitrile
Butylammonium barchlorate 0.68 f (0
, 1 mol/l) and the above-mentioned exemplified compound A4 as a monomer.
are dissolved using a magnetic stirrer at room temperature, and this solution is transferred to an electrolytic cell. Polymerization was carried out by the triode method, using ITO glass (5 x 30 + w, surface resistance 20-50
Ω), using platinum wire as the counter electrode and SCE as the reference electrode, Ov-N, 5V-+OV running speed 5Q with respect to SCE
Polymerization was carried out by applying a potential of 7 cycles at mV/sec. The cyclic portagram during polymerization is shown in FIG. As the number of runs increases, the waveforms different from the oxidation and reduction waves of the monomer, that is, the doping waveform around +0.5V 1 and the dedoping waveform of the film around -0.2V, become larger. The resulting film is red in color and can be mixed with methanol, acetone,
It was insoluble in tetrahydrofuran and dimethylformamide.

Example 2 Under the same conditions as Example 1, constant potential 1.
When polymerization was carried out at 5V for 20 seconds, a true green thin film was formed on the other side of the electrode.

The ITO electrode with this film attached was heated using acetonitrile/tetra-n-butylammonic perchloride) (0.1 m
A platinum wire was used as a counter electrode in a solution of 0V-41, 2V-eOV with respect to reference electrode 5 (JK).

A triangular wave was applied at a running speed of 50 mV/sea to dope and dedope the polymer film. As a result, a cyclic portumgram as shown in FIG. 4 was obtained, and this film was electrochemically active, doping and dedoping occurred reversibly, and an accompanying change in film color was also observed.

Example 6 An electrolytic solution was prepared in the same manner as in Example 1 except that the above-mentioned exemplified compound A5 was used as a monomer, and a working electrode,
The counter electrode and reference electrode used were the same as in Example 1, and the voltage was set at 0V41.5V with respect to the reference electrode SCE→Ov running speed 50 mV.
Polymerization was carried out by applying a potential of /see for 6 cycles. Figure 5 shows the cyclic portum during polymerization. As the number of runs increases, the waveform differs from the oxidation and reduction waves of the monomer, that is, the doping waveform of the film around 100.7V, and -0,
The dedoping waveform of the film near 3'/ becomes larger.

The resulting film had a pale yellow color and was insoluble in acetone and tetrahydrofuran.

Example 4 Constant potential tS with respect to the reference electrode scg under the same conditions as Example 5
Polymerization was carried out at V for 10 seconds. A dark green thin film was formed on the electrode surface. The ITO electrode to which this film was attached was placed in a solution of acetonitrile/tetra-n-butylammonium perchloride (0.1 mot/l), using a platinum wire as a counter electrode, and 1.0 V-el versus the reference electrode SCE. 2V-
A triangular wave was applied at a +OV running speed of 50 mV/see to dope and dedope the polymer film. As a result, a cyclic portumgram as shown in Figure 6 was obtained, and this film was electrochemically active and doping and dedoping occurred reversibly.
An accompanying change in film color was also observed.

Example 5 Polymerization was carried out for 20 seconds under the same formulation and conditions as in Example 1, except that the above-mentioned Exemplified Compound A7 was used as a monomer.

A yellow thin film was formed on the electrode surface. This membrane was insoluble in acetone and tetrahydrofuran. The ITO electrode with this film attached was prepared using acetonitrile/tetra-n-butylammonium nochloride) (0.1 moL/L).
), a platinum wire was used as the counter electrode, and the reference electrode 8C
0′V4t2v→Ov traveling speed 100 mV/
A triangular wave was applied at sec to perform doping and dedoping of the polymer film.

As a result, a cyclic portumgram as shown in FIG. 7 was obtained, and this film was electrochemically active and doping and dedoping occurred reversibly, and an accompanying change in film color was also observed.

Example 6 Acetonitrile as solvent 20-1 Tetra-n-butylammonium barchlorate as electrolyte 0.68
t (α1 mol/l), the above-mentioned Exemplified Compound A as a monomer (5 mmoL/l) was prepared, the electrolyte, additives, and monomer were dissolved in the solvent, and a reference electrode was prepared using the triode method. A polymer film was formed on an ITO glass plate for 20 seconds at a constant potential tSV of 80E. Thoroughly wash the electrode with this polymer film attached with methanol, and then remove it from the other IT electrode.
A solution of propylene carbonate/tetra-n-butylammonium perchloride (0,j mot/l) was sealed between the glass plate and the glass plate through a 13 μm Mylar spacer to produce an electrochromic display element. In this display element, doping and dedoping of the polymer occurred reversibly by voltage application, and the color changed to red, colorless, yellow, green, blue, and dark blue.

Example 7 A polymer film was formed on ITO glass by pressing in the same manner as in Example 6, except that the above-mentioned Exemplified Compound A5 was used as a monomer, and an electrochromic display element was similarly prepared. In this display element, doping and dedoping of the polymer occurred reversibly by voltage application, and the color changed to colorless #yellow #green #blue #dark blue.

Example 8 A polymer film was prepared on ITO glass in the same manner as in Example 6, except that the above-mentioned Exemplary Compound A7 was used as a monomer, and an electrochromic display element was also prepared. In this display element, doping and dedoping of the polymer occurred reversibly by voltage application, and the color changed to colorless #yellow #green #actual color.

The electrochromic display elements produced in Examples 6 to 8 were colorless when decolored, changed to multiple colors, had large contrast, and had no unevenness in one color. It also had excellent repeatability.

〔effect〕

As described above, the electrolytic polymer obtained by electrolytic polymerization using the compound represented by the above formula as a monomer is an electrically active film that will be used as a functional polymer in solar cells, secondary batteries, image sensors, etc. It is expected to be applied to various devices such as -, electrochromism, and displays.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIGS. 1 and 2 are schematic sectional views showing examples of the electrochromic display element of the present invention, and FIGS.
The figure shows a cyclic portum gram during electrolytic polymerization according to the present invention, and FIGS. 4, 6, and 7 show cyclic portum gram of an electrolytically polymerized membrane according to the present invention. Patent applicant Ricoh Co., Ltd. - 2 other people, 1 figure, 2 figures, 3 areas

Claims (1)

[Claims] 1) Formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, X represents 0 or S, and m, m', n and n' represent integers from 0 to 2, n = 2-m and n' = 2-m') by an electrolytic polymerization method. 2) Formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, An electrochromic display element using an electrolytic polymer produced by an electrolytic polymerization method from a compound having n'=2-m'.