JPS62115426A - Electrochromic element - Google Patents

Abstract

PURPOSE:To obtain the titled element having an excellent stability by using a high polymer composite film obtd. by polymerizing a monomer capable of forming a conductive high polymer with a polymerization, in a porous high polymer film. CONSTITUTION:The polymerization is carried out by using the porous high polymer film made of an ethylene-2-methylpenten copolymer as a diaphragm 2, and by feeding a chloroform solution saturated with an anhydrous ferric chloride into a cell 1 for the solution of an oxidizing reagent, and introducing slowly a nitrogen gas saturated with thiophene to the cell 3 for a gaseous monomer. And then, the film 2 is take out and washed with an ethanol and an ammoniacal ethanol solution in order. The composite film is deposited with gold on a side of the cell contacting with an oxidizing reagent, and then is dipped with an acetonitrile solution of lithium perchlorate followed by taking it out. The cell of the electrochromic element is assembled using a counter electrode composed of 'NESA(R)' glass.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an electrocomic device using a compound that reversibly changes color through an electrochemical redox reaction. Specifically, the present invention relates to an electrochromic device using a polymer composite membrane in which a conductive polymer is polymerized in a porous polymer membrane.

[Conventional technology]

It is known that the optical properties of a conductive polymer, such as its light transmission spectrum and reflection spectrum, change by doping the conductive polymer with a dopant. Utilizing this phenomenon, for example, voltage-responsive optical functional devices have been developed that utilize changes in the optical properties of conductive polymers that respond to the applied voltage when electrochemically doped and dedoped by applying a voltage. (Japanese Unexamined Patent Publication No. 59-129827).

[Problem that the invention seeks to solve]

In order to take advantage of the light transmittance and color change of conductive polymers, these conductive polymers need to be in the form of a thin film. Further, in order to exhibit the function as an element, it is necessary to form these conductive polymers on a metal plate or conductive glass. Furthermore, the formed conductive polymer film is thin, has low strength, is difficult to handle, and has the problem that the bonded portion with the electrode is easily peeled off.

An object of the present invention is to provide an electrochromic device that solves these problems.

[Means for solving problems]

The present inventors conducted extensive studies to solve these problems and completed the present invention.

That is, the present invention is an electrochromic device comprising an electrode and a polymer composite membrane obtained by polymerizing monomers that can be polymerized to form a conductive polymer in a porous polymer membrane.

The polymer composite membrane used in the present invention is formed by polymerizing a conductive polymer into a porous polymer membrane.

The porous polymer membrane has a pore diameter of 0.001 μm to 1
μm is used. The materials include organic compound polymers and inorganic compound polymers, such as molded products such as polypropylene, polyethylene, and polyvinyl chloride, molded products such as glass wool and silicone-treated paper, and composite molded products of these. shown.

There are no particular restrictions on the method for producing the porous polymer membrane, and examples include a method in which a mixture of a thermoplastic resin and an inorganic filler is melt-formed into a film and then stretched; There are methods such as dissolving and extracting with a solvent. Alternatively, glass wool, cellulose fiber, or the like may be compression-molded to form a membrane.

The conductive polymer used in the present invention is obtained from a monomer that becomes a conductive polymer with an oxidizing agent such as pyrrole, thiophene, furan, or aniline.

Various oxidizing agents can be used here, including inorganic acids, peroxides, and Lewis acids.

As a method for polymerizing a conductive polymer into a porous polymer membrane, a method is preferred in which the monomer is brought into contact with an oxidizing agent using the porous polymer membrane as a partition wall.

Dissolving the oxidizing agent in a suitable solvent such as water, alcohols, halogenated hydrocarbons, nitrated hydrocarbons, etc.
This solution and the above monomer gas are diluted with an inert gas such as nitrogen or helium as necessary, and brought into contact using a device as shown in Figure 1, using a porous polymer membrane as a partition. good.

In the figure, 1 is a cell for oxidizing solution, 2 is a partition wall of a porous polymer membrane, 3 is a cell for monomer gas, a and b are oxidizing solution inlets and outlets, and c and d are for monomer gas. It is an entrance/exit.

This contact treatment can also be carried out continuously.

The concentration of the oxidizing agent solution used here is not particularly limited, but is 0.001 to 5 mol/1, preferably 0.001 to 5 mol/1.
01 to 1 mol/'+ is appropriate. There are no particular restrictions on the time and temperature of the contact treatment, and they may be determined as appropriate to obtain the desired amount of polymer.
00 minutes is appropriate.

By washing the obtained membrane with ethanol, ammoniacal ethanol, etc., a polymer composite membrane containing no dopant can be obtained. This composite membrane is tough, flexible, and easy to handle. Furthermore, while thick films of conductive polymers are usually black in color, this polymer composite film has the vivid color of conductive polymers even though it is a thick film.

The electrocomic device of the present invention is obtained by placing the composite membrane obtained above and a counter electrode facing each other with an electrolyte interposed therebetween.

Nickel, platinum, conductive glass, etc. can be used as the counter electrode.

The electrolyte is present between the composite membrane and the counter electrode as a solution or a solid electrolyte, but it may also be simply impregnated into the porous composite membrane itself.

Moreover, since many polymer composite films are similar to insulators before being doped with a dopant, it is preferable to vapor-deposit a metal or coat a conductive paste on the polymer composite film.

As the electrolyte, inorganic salts such as perchlorates, fluoroborates, hexafluorophosphates, chlorides, bromides, and iodides, and organic salts such as alkylbenzene sulfonates and amino acid salts are used.

Examples of the electrolyte solvent include hendinitrile, acetonitrile, propylene carbonate, tetrahydrofuran, water, and the like, but are not particularly limited.

A cell configured in this manner exhibits electrochromism by applying a voltage between opposing electrodes.

An example of a cell is shown in Figure 2. In the figure, 4 is a counter electrode, 5 is a polymer composite membrane impregnated with an electrolyte, 6 is an electrode opposite to 4, 7 is a switch, 8 is a battery, and 9 is a battery having a polarity opposite to that of 8.

〔Example〕

The present invention will be explained below with reference to Examples.

Example 1 The partition wall 2 of the apparatus shown in FIG. 1 had an average pore diameter of 0.4 μm,
20μ thick? Using an ethylene/2-methy)5-pentene copolymer porous polymer membrane (manufactured by Mitsui Toatsu Chemical Co., Ltd.), an anhydrous ferric chloride saturated chloroform solution was placed in cell 1 for the oxidizing agent solution, and the monomer Nitrogen gas saturated with thiophene was slowly introduced into the gas cell 3, and polymerization was carried out for 10 minutes. Thereafter, the membrane 2 was taken out and washed with ethanol, and further washed with ammoniacal ethanol. The obtained composite membrane was red in color, and the electrical conductivity on the oxidant solution cell side was 10-''s/am. Gold was evaporated on the oxidant solution cell side of this composite membrane. After immersing it in an acetonitrile solution of 0.5 mol 71 lithium perchlorate for 30 minutes, it was taken out, and an electrochromic device cell as shown in FIG. 2 was assembled using Nesa glass as a counter electrode.

When the composite membrane side of this cell was used as an anode and Nesa glass as a cathode, and a voltage of 4 μ was applied between both electrodes, the composite membrane turned from red to blue. Next, the applied voltage is
When the color of the composite film was changed from blue to red.

Example 2 As a porous polymer membrane, a porous polymer membrane with a thickness of 25 μm mainly made of polypropylene manufactured by Polyplastic ■ "Shelagard 2500" (trademark, maximum pore diameter 0.4 Xo) was used.
.

The color of the composite membrane is red, and its electrical conductivity is IQ
-'s/c+m.

When the composite membrane side of this cell was used as an anode and Nesa glass as a cathode, and a voltage of 5 μ was applied between both electrodes, the composite membrane turned from red to blue. Then, the applied voltage was increased to -2V.
When the color of the composite film was changed from blue to red.

〔Effect of the invention〕

The electrochromic device of the present invention can be used as a voltage-responsive optical switch, color switch, or optical memory, and the incorporated composite film is strong and stable, so the device is stable. It's excellent to scratch.

[Brief explanation of drawings]

Figure 1 is a conceptual diagram of an example of manufacturing equipment suitable for manufacturing the polymer composite membrane used in the present invention, and Figure 2 is a conceptual diagram of an example of a cell incorporating the electrochromic element of the present invention. be. 1 is a cell for an oxidizing agent solution, 2 is a porous polymer membrane partition, 3 is a cell for an oxidizing agent solution;
is a monomer gas cell, a and b are oxidizing agent solution inlets and outlets, and c and d are #mer gas inlets and outlets. Further, 4 is a counter electrode, 5 is a polymer composite membrane impregnated with an electrolyte, 6 is an electrode opposite to 4, 7 is a switch, 8 is a battery, and 9 is a battery having a polarity opposite to that of 8. Patent applicant Mitsui Toatsu Chemical Co., Ltd. Figure -

Claims (1)

[Claims] 1. An electrochromic device consisting of a polymer composite membrane obtained by polymerizing a monomer that forms a conductive polymer in a porous polymer membrane and an electrode.