JPS6337119A - Novel electrolytic polymer and electrochromic display element obtained by using said polymer - Google Patents

Abstract

PURPOSE:To obtain a novel electrochemically active multi-color electrolytic polymer for display elements, having large contrast, free from color unevenness and excellent in repeating performance. CONSTITUTION:A monomer selected from a compound expressed by formulas I-VI (R1 is H, 1-5C substitutive alkyl, etc.; R2 and R4 are substitutive aryl; R3, R5, R7-R9 are 1-5C substitutive alkyl; R6 is 1-5C alkyl or substitutive alkyl; m and n are 1 or 2) is electrolytically polymerized to provide the aimed polymer. The above-mentioned electrolytic polymerization is preferably carried out by a three-pole method, in which silver/silver chloride or SCE is preferably used as a reference electrode. Examples of a solvent used for the electrolytic polymerization include acetonitrile, etc. As an electrolyte, for example, tetra-n- butylammonium perchlorate, etc., may be used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel polymers that are electrochemically active, ie, capable of doping and dedoping with electrolyte ions by electrochemical means.

The present invention also relates to a display element using such a polymer as an electrochromic material.

BACKGROUND ART Conventionally, 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 voltage is applied to deposit a polymer on the electrode surface.

The following representative reports are examples of polymers obtained by electrolytic polymerization.

(a) Regarding polypyrrole ■ U.S. Patent No. 3,574,072 ■ A, F, Diaz, et al, , J, C, S, Ch
em, Comm,.

■A, F, Diaz, et al,, J, C, S, Ch
em, Comm,.

(b) Regarding polythenylene, Kaneto, at al., J.C.S., Che.
l,Comm,.

(c) About polyaniline A, F. Diaz, et al., J. Eleetro
anal, Chem.

Kawa, 111 (I980) T, Ohsaka, et al, J, Electro
anal, Chen+,.

Laurel, 399 (I984) Monomers for which electrochemically active polymers have been obtained by applying the electrolytic polymerization method, including the above report, include pyrrole, pyrrole derivatives, thiophene, and thiophene derivatives. , furan, aniline, aniline derivatives, etc., and there are very few types.

Furthermore, display elements are known that utilize the so-called electrochroming phenomenon, in which light absorption changes when an electric field is applied, and recovers reversibly when the electric field is removed. This display element basically has an electrochromic layer interposed between a counter electrode and a display electrode, and the layer contains an electrochromic material.

Conventionally, WO3 is well known as an inorganic electrochromic material.

Known organic substances include viologen, pyrazoline, anthraquinone, and styryl-based pigments.

In W○□, an element is formed by forming a thin film on a transparent electrode by vapor deposition or the like, and providing an electrolytic solution, a dielectric film, etc. between the counter electrodes.

Practical problems with WO□ include, in addition to the display life, color unevenness between display segments and the fact that the type of coloring is a single blue color.

In addition, in order to stabilize the counter electrode reaction, special measures must be taken in the material of the counter electrode, and there are also problems in that a reflecting plate and the like must be incorporated into the element. Organic pigments such as viologen-based pigments develop color when reduced, and return to a decolored state when oxidized. The problem with viologen systems is that they have a short display life. The reason for this is that the dye becomes insolubilized in the solvent in the coloring state, and the phenomenon of soluble and insoluble dyes occurs depending on whether the color fades or develops, but there is a problem with this reversibility. 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.

The object of the present invention is to provide a novel electrochemically active electrolytic polymer.

Another object of the present invention is to provide a display element using an electrochromic material that is multicolored, has a strong contrast, is free from color unevenness, has excellent repeatability, and is easy to produce. .

Mitsuru” B Yatan Mei.

The electrolytic polymer of the present invention is characterized in that it is produced by an electrolytic polymerization method using a compound represented by the following structural formula (I) as a monomer.

(In the formula, R□ represents a substituted or unsubstituted alkyl group of hydrogen C□ to C5, or a substituted or unsubstituted aryl group.) (The symbols in the formula are as follows. R2: Substituted or unsubstituted aryl group.

n: 1 or 2) R1 (Symbols in the formula are as follows. R: C-Cs substituted or unsubstituted alkyl group.

R4: Substituted or unsubstituted aryl group.

m: 1 or 2) (The symbols in the formula are as follows. R: C, -C6 substituted or unsubstituted alkyl group.

R,: C, to C8 alkyl group, or substituted or unsubstituted alkyl group) (blank below) (In the formula, R,, R, represents a C to C9 substituted or unsubstituted alkyl group, and the same (In the formula, R represents a C1 to C6 substituted or unsubstituted alkyl group.) The electrochromic display element of the present invention uses the above structural formula (I) as an electrochromic material. It is characterized by using a polymer obtained by electrolytically polymerizing a compound represented by ~(■).

The present invention will be explained in more detail below.

Representative examples of the thiophene derivative represented by general formula (n) or (m) include the following.

Further, as representative examples of the carbazole derivatives represented by the general formula (IV) or (■), the following can be exemplified.

(Margin below) Compound teeth ・ C,H.

C,H.

C2H.

(Margin below) C2H.

The solvent used when electrolytically polymerizing the above monomers is one that has a high dielectric constant and dissolves the electrolyte well. Specific examples of such solvents include acetonitrile, benzonitrile, Examples include propylene carbonate, alcohol, dimethylformamide, nitrobenzene, N-methylpyrrolidone, tetrahydrofuran, dimethylsulfoxide, and the like.

These solvents are preferably subjected to distillation in order to remove impurities. The solvents may be used alone or as a mixture of two or more solvents, and a small amount of water may also be mixed.

As the electrolyte, organic or inorganic salts or double salts, complex salts, ionic dyes, etc. which are soluble in organic solvents and easily dissociate into ions are used. Specifically, for example, (n-C
4H,), N-ClO4゜(C2H,)4N-BF,,
(CzHs)4N-Hso,.

(n-C,H,)4N-CH3()-8o,.

(C,H,),N-P F,,L i CI O4,N
a As F,.

A g B F4. Roast Bengal etc. are used.

These electrolytes are preferably used after being purified and dried under vacuum. The concentration of electrolyte used in the polymerization was 0. O1～
1.0m. A range of 1/12 is appropriate.

Preferably it is in the range of 0.05 to 0.3 Ilol/Q.

The concentration of the monomer depends on its solubility in the solvent used, but in the membrane it is used in the range of 1 mmol/Q to 11 ol/Q.

In addition, hydrogen acceptors 2 and 6 may be added as additives depending on the case.
- Addition of lutidine, pyridine, 2,4,6-collidine, etc. greatly promotes polymer formation. The concentration of the additive is within limits, but is preferably in the range of equimolar to 20 times the molar amount of the monomer.

Although the electrolytic polymerization reaction can be carried out using a bipolar system or a bipolar system, it is preferable to perform the electrolytic polymerization reaction using a bipolar system because constant potential or constant current polymerization can be performed.

In the case of the bipolar method, a single-film reference electrode can be used, but SCE or silver/silver chloride is preferably used.

Polymerization is possible at an electrolytic voltage of 2 V or more relative to SCE, but constant potential, constant current, or cyclic potential may be used for single polymerization. As an electrode material, IT is used as a working electrode.
O glass, Nesa glass, platinum plate, carbon electrode, etc.
Further, a platinum wire, a nickel plate, etc. can be used as a counter electrode.

Electrolytic polymers obtained using compounds of general formulas (I) to (■) as monomers are electrically active membranes, and electrolyte ions can be doped and dedoped by electrochemical methods. . Such polymer films are expected to be applied to various devices such as solar cells, dual-cell batteries, image sensors, and electrochromism displays.

Polymers obtained by electrolytic polymerization using compounds represented by formulas (I) to (■) as monomers are suitable as electromic materials. FIG. 1 is a sectional view showing an example of the structure of an electromic display element using this polymer, in which a first substrate 11 having one display electrode 13 and a counter electrode 2
The electrolytic polymer 15 of the present invention, which is an electromink material, is adhered onto the six display electrodes 13, which are arranged to face and be spaced apart from the second substrate 21 having the electrodes 21 with a spacer 31 in between. A solvent 1 containing a supporting electrolyte is placed between the substrates 11 and 21 via a spacer 31 such as Mylar or Teflon.
7 is enclosed and sealed with a sealant 33. The picture electrodes 13.23 are connected to a power source, a circuit, etc. through lead wires, and are driven.

The position where the electromink material is formed and the electrode structure are not limited to those shown in FIG. 1. For example, the electrolytic polymer may be formed on the counter electrode 23 as shown in FIG. 2. In addition, as shown in FIG. 3, the display ffi electrode 13 and the counter electrode 2
3 may be formed on the same substrate.

As the substrates 11 and 21, a transparent body is used for either one (<am side), and an appropriate material such as glass or plastic can be used.

The electrodes 13.23 are made of transparent conductive materials such as indium oxide, tin oxide, and indium tin oxide (ITO), or metal materials such as platinum, gold, and aluminum. It is formed from electrodes.

The material and forming method of the electrolytic polymer 15 are as already described in detail.

The solvent for the supporting electrolyte-containing solvent 19 is one that has a high dielectric constant and dissolves the electrolyte well, and may be used alone or in combination of two or more solvents.

Specific examples of such solvents include, for example, acetonitrile, benzonitrile, propylecarbonate, alcohol, dichloromethane, chloroform, 1,2-dichloroethane, acetone, nitromethane, ethyl acetate, pyridine, tetrahydrofuran, dioxane, dimethylformamide, nitrobenzene. , N-methylpyrrolidone,
Examples include dimethyl sulfoxide and water.

Further, as the supporting electrolyte, a salt soluble in the solvent used is used. An example is LiCQO4°Li BF4. N
H4CQO,, (CH,)4N-C:Q.

(C2H,)4N-CQ, (C2H,)4N-Br.

(C2H,)4N-CN, (CzHs), N-CQO,
.

(C2H5)4 N-B F4 , (C4Hg)4 N
-c Q04-(C4H,), N-BF4. (C, H,
)4N-H8O,.

A g CQ O4? Examples include A g B F4.

Electrochromic phenomena caused by electrolytic polymers are also known for polypyrrole, polythenylene, polyaniline, etc., and dopants such as perchlorate ions, borofluoride ions, etc. are added to the polymer. This is caused by a change in the electronic state in the polymer caused by doping or dedoping with iodine or the like.

The polymer compound obtained by subjecting the compounds of general formulas (I) to (■) of the present invention to electrolytic polymerization as monomers is as follows:
obtained as an electrically active film, 118! As a functional polymer, it is expected to be widely applied in the field of electrical materials. Further, an electromink display element using this electrolytic polymer as an electromic material can display multiple colors, has little color unevenness, has excellent repeatability, and can be easily produced.

EXAMPLES Hereinafter, the effects of the present invention will be explained in more detail with reference to Examples.

Example 1 Solvent = Acetonitrile 20 Electrolyte resistant: Tetra-n-butylammonium barchlorate 0.68 g (0.1 mol) Octagonal hemolyte: Benzo(C) cinnoline 0.036 g (0.01 mol/Q) The electrolyte and monomer are dissolved in a solvent using a magnetic stirrer at room temperature and transferred to an electrolytic cell. Polymerization is performed by the bipolar method.
ITO glass (5X30Ql, surface resistance 20-30Ω) as working electrode, platinum wire as counter electrode, SC as reference electrode
Using E, 0V43.0V-40V for S CH,
Polymerization was performed by applying one cycle of triangular waves at a running speed of 50 mV/see. A uniform brown thin film was formed on the electrode surface. This membrane was insoluble in acetonitrile.

The ITO electrode with this film attached was coated with propylene carbonate/tetra-n-butylammonium barchlorate (0
, 1 mol/Q), the polymer film was doped and dedoped by applying triangular waves for 3 cycles at 0.5 V - + - 0,5 V - + 0.5 V and a running speed of 50 V/sec to the reference SCE. went. 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 primary colors was also observed.

Example 2 Solvent Niacetonitrile 20ml Electrolyte: Tetra-n-butylammonium barchlorate 0.68 g (0.1 mol/Q) Monomer: Compound NoI O, 056 g (0.01 mol/Q)
) Dissolve the electrolyte and monomer in the above solvent at room temperature using a magnetic check stirrer and transfer to an electrolytic cell. Polymerization was carried out using a bipolar method, using ITo glass (5X 30++
+n+, surface resistance 20 to 30 Ω), a platinum wire as a counter electrode, and SCE as a reference electrode.
Polymerization was performed by applying one cycle of a triangular wave at OV+2V-+OV and a running speed of 50 mV/see. A uniform orange thin film was formed on the electrode surface. This membrane was insoluble in acetonitrile. The IToffi electrode with this film attached was treated with propylene carbonate/tetra-n-butylammonium barchlorate (0.1 mol) in a solution of 80 g.
S CE Ov → 1.5v → Ov, running speed 5
A triangular wave was applied at 0 mV/sec to perform doping and dedoping of the polymer film. As a result, a cyclic portumgram as shown in FIG. 5 was obtained, and this film was electrochemically active, doping and dedoping occurred reversibly, and an accompanying change in primary colors was also observed.

Examples 3 to 7 Same as Example 2, only the monomer was used as compound NQ2
When electrolytic polymerization was carried out using Samples 6 to 6, uniform yellow thin films were obtained in all cases. For each film, the current and primary color changes associated with doping and dedoping are wA? I1g and was found to be electrochemically active.

Example 8 Solvent Niacetonitrile 20+al Electrolyte: Tetra-n-butylammonium barchlorate 0.68 g (0,1+*ol/Q) Monomer: Compound Nα7 0.059 g (0,01 mol/Q) Above The electrolyte and monomer are dissolved in a solvent using a magnetic stirrer at room temperature, and transferred to an electrolytic cell. Polymerization is carried out by the bipolar method,
ITO glass (5 x 30 mm, surface resistance 2
0~30Ω), platinum wire as counter electrode, SCE as reference electrode
Polymerization was carried out using one cycle of triangular waves applied to SCE at OV-+2V40V and a running speed of 50 mV/see. A uniform yellow thin film was formed on the electrode surface. This membrane was insoluble in acetonitrile. The ITO electrode with this film attached was coated with propylene carbonate/tetra-n-butylammonium barchlorate (0.1 mo
OV−+ relative to the reference SCE in a solution of l/Q)
One polymer film was doped and undoped by three cycles of triangular waves at 1.5 V-+OV and a running speed of 50 mV/see. As a result, a cyclic portumgram as shown in Figure 6 was obtained, and this film was electrochemically active, doping and dedoping occurred reversibly, and the accompanying changes in primary colors were also i.
It was measured.

Examples 9 to 15 In the same manner as in Example 8, electrolytic polymerization was performed using compounds Nα8 to 14 as monomers only, and a uniform yellow thin film was obtained. Changes in current and primary colors due to doping and dedoping were observed in each film, and it was found that each film was electrochemically active.

Comparative Example 1 Electrolytic polymerization of only the monomer using N-ethylcarbazole was performed under the same conditions as in Example 1, and no precipitation of the polymer was observed on the electrode.

Example 16 Solvent Niacetonitrile 20+al Electrolyte: Tetra-n-butylammonium verchlorate 0.68 g (0.1 mol/Q) Monomer: Benzo[C]cinnoline 0.036 g (0.01 mol/fl) Above Dissolve the electrolyte and monomer in the solvent and use S as a reference electrode using the two-electrode method.
Approximately 0.1 on IT○ glass at a constant potential of 2.5■ against CE
A μm polymer film was created. Thoroughly rinse the electrode with this polymer film attached with methanol, and add propylene carbonate/tetra-n-butylammonium barchlorate (0.1 mol/Ω) between it and another piece of IT○ glass through a 13μI mylar spacer. The solution was sealed to create an electrochromic display element. In this device, as voltage was applied, doping and dedoping of the polymer occurred reversibly and the color changed from orange to blue. This electrochromic element is
It showed a uniform and very clear color change. Moreover, the repeatability was also excellent.

Example 17 Solvent: Niacetonitrile 20ml Electrolyte: Tetra-n-butylammonium barchlorate 0.68g (0.1mol) Octagonal hemistomer: Compound Nα1 0.056g (0.01mol/Q) Electrolyte in the above solvent, An electrochromic display element was prepared in the same manner as in Example 16, except that the monomers were dissolved to form a polymer film.In this element, doping and dedoping of the polymer occurred reversibly with the application of voltage. The color changed from orange to black.

Example 18 Polymerization was carried out under the same conditions as in Example 17 except that only the monomer was changed to the compound Na2, and an electrochromic display element was created. A reversible color change from orange to black was observed.

Example 19 An electrochromic display element was produced by polymerization under the same conditions as in Example 17 except that only the monomer was changed to compound Ma4. A reversible color change from tan to black was observed.

The electrochromic display elements of the present invention in Examples 17 to 19 all showed uniform and very clear color changes6.
Moreover, the repeatability was also excellent.

Example 20 Solvent Niacetonitrile 20-1 Electrolyte: Tetra-n-butylammonium verchlorate Q, 68 g (0.1 mol/Q) Monomer: Compound &7 0.059 g (0.01+ol HaD) Above solvent An electrochromic display element was prepared in the same manner as in Example 16, except that the electrolyte and monomer were dissolved in the liquid to form a polymer film.In this element, doping and dedoping of the polymer were reversible with the application of voltage. The color changed from pale yellow to green (blue-green).

Example 21 Polymerization was carried out under the same conditions as in Example 20 except that only the monomer was changed to compound NQ8, and an electrochromic display element was created. As a result, a bright pale yellow color appeared as voltage was applied.
A reversible color change from green to blue-green occurred.

Example 22 Polymerization was carried out under the same conditions as in Example 20, except that only the monomer was changed to Compound Demon 9, and an electrochromink display element was created. As a result, a bright pale yellow = yellow-green color appeared as voltage was applied. = A reversible color change of green occurred.

Example 23 Example 20 except that only the monomer was changed to compound Na12
When polymerization was carried out under the same conditions as above to create an electrochromic display element, a clear reversible color change from light brown to black occurred as voltage was applied.

Example 24 Example 2 except that only the monomer was changed to compound N[113
When polymerization was carried out under the same conditions as in Example 0 to prepare an electrochromic display element, a clear reversible color change from pale yellow to yellow to green to blue occurred as voltage was applied.

Example 25 Polymerization was carried out under the same conditions as in Example 20, except that only the monomer was changed to compound &14, and an electrochromic display element was created. As a result, a bright pale yellow color appeared as voltage was applied.
A reversible green=blue color change occurred.

The electrochromic display elements of Examples 20 to 25 of the present invention all showed uniform and very clear color changes.

Moreover, the repeatability was also excellent.

[Brief explanation of drawings]

FIG. 1, FIG. 2, and FIG. 3 are schematic cross-sectional views showing an example of the structure of an electrochromic display element of the present invention. FIG. 4, FIG. 5, and FIG. 6 are cyclic portum diagrams of electrolytic polymers obtained in Examples of the present invention. 11... First substrate 13... Display electrode 15
... Electrolytic polymer

Claims (1)

[Claims] 1. The following structural formulas (I), (II),
(III), (IV), (V), (VI) or (VII) ▲There are mathematical formulas, chemical formulas, tables, etc.▼…(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼…(II) (In the formula , R_1 represents hydrogen, a substituted or unsubstituted alkyl group of C_1 to C_5, or a substituted or unsubstituted aryl group.) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(III) (The symbols in the formula are as follows. R_2: Substituted or unsubstituted aryl group, n: 1 or 2) ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼...(IV) (Symbols in the formula are as follows R_3: C_1 to C_5 Substituted or unsubstituted alkyl group, R_4: Substituted or unsubstituted aryl group, m: 1 or 2) ▲There are numerical formulas, chemical formulas, tables, etc.▼...(V) (The symbols in the formula are as follows. R_5: C_1 to C_5 substituted or unsubstituted alkyl group, R_6: C_1 to C_5 alkyl group, or substituted or unsubstituted alkyl group) ▲There are numerical formulas, chemical formulas, tables, etc.▼...(VI) (In the formula, R_7 and R_8 represent substituted or unsubstituted alkyl groups of C_1 to C_5, and may be the same or different.) ▲There are numerical formulas, chemical formulas, tables, etc.▼...(VII) (In the formula, R_9 is the substituted or unsubstituted alkyl group of C_1 to C_5. (representing a substituted or unsubstituted alkyl group) An electrolytic polymer produced using a compound represented by the following as a monomer. 2. In an electrochromic display element that performs display by applying an electric field to an electrochromic material and changing the light absorption characteristics of the material, the electrochromic material may have the following structural formulas (I), (II), or (III). ), (I
V), (V), (VI) or (VII) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) (In the formula, R_1 is hydrogen, Represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group of C_1 to C_5.) ▲There are numerical formulas, chemical formulas, tables, etc.▼...(III) (The symbols in the formula are as follows.R_2 : Substituted or unsubstituted aryl group, n: 1 or 2) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(IV) (Symbols in the formula are as follows R_3: Substituted or unsubstituted C_1 to C_5 alkyl group, R_4: substituted or unsubstituted aryl group, m: 1 or 2) ▲There are numerical formulas, chemical formulas, tables, etc.▼...(V) (Symbols in the formula are as follows R_5: C_1 to C_5 Substituted or unsubstituted alkyl group, R_6: C_1 to C_5 alkyl group, or substituted or unsubstituted alkyl group) ▲Mathematical formulas, chemical formulas, tables, etc.▼...(VI) (In the formula, R_7 and R_8 are C_1 ~C_5 represents a substituted or unsubstituted alkyl group, which may be the same or different.) ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(VII) (In the formula, R_9 represents a substituted or unsubstituted alkyl group of C_1 to C_5. An electrochromic display element characterized by using an electrolytic polymer produced by an electrolytic polymerization method using a compound represented by (representing an alkyl group) as a monomer.