JPH05301913A - Etherified vinyl alcohol polymer, its production and color-developing and color-changing material composed of the polymer - Google Patents

Abstract

PURPOSE:To provide a polymeric substance having a specific structure, soluble in solvent, having polarity and exhibiting electrochromic color-development and discoloration. CONSTITUTION:The etherified vinyl alcohol polymer expressed by formula [R is residue of an electrically conductive polymer or copolymer exhibiting color-development or discoloration by oxidation and reduction; L, M and N are integers satisfying the formulas 1<=L<=(N-M) and 1<=M<=(N-L); N is integer of 10-12,000]. The polymer can be produced by reacting a halogen compound of the formula RX (X is halogen) with a vinyl alcohol polymer. The polymer has excellent color-developing and discoloration capabilities and high adhesive strength to electrode, etc. It can be formed to a film having large area and is useful as an highly practical and advantageous material for electrochromic display element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel coloring / discoloring material using electrochromism and a method for producing the same.

[0002]

2. Description of the Related Art Electrochromism refers to a phenomenon in which a color or light transmittance is reversibly changed by an oxidation-reduction reaction that occurs on or near an electrode surface when a voltage is applied. Various materials have been reported as the electrochromic material exhibiting the above, and their application to display devices has been attempted. As a conventional coloring material using electrochromism, one using a metal oxide such as tungsten oxide as described in JP-B-52-46098, JP-A-51.
Japanese Patent Application Laid-Open No. SHO 56-6-6, which uses an organic low-molecular compound such as viologen in solution as described in JP-A-146253.
As disclosed in Japanese Patent No. 7881, there is known one using an electrically conductive polymer having a conjugated double bond in its main chain.

[0003]

In the case of the conventional coloring material using electrochromism, the metal oxide is produced by a vacuum process such as sputtering as described in JP-A-54-41756. There is a problem that it is difficult to coat a large area. on the other hand,
In the case of an organic low molecular weight compound, an electrochromic display device is prepared by using the compound.
As described in Japanese Patent No. 146253, a semipermeable membrane is interposed between an electrode plate and a transparent electrode plate, and a solution containing a supporting electrolyte is allowed to exist between the electrode plate and the diaphragm to form a transparent electrode plate. It is necessary to allow a solution containing an organic low molecular weight compound such as viologen and a supporting electrolyte to be present between the diaphragm and
There is a drawback that the structure of the electrochromic display element becomes complicated. Further, an electrically conductive polymer having a conjugated double bond in the main chain is directly polymerized on the electrode surface by electrolytic polymerization or the like as described in JP-A-60-188931, but it can be inexpensively formed into a large area. It is difficult to coat. In addition, an electroconductive polymer that is soluble in a solvent and has a conjugated double bond in the main chain is generally non-polar, and has poor adhesiveness with an electrode or an electrolyte that is a polar surface. for that reason,
It was not possible to obtain strong adhesion, leaving problems such as peeling.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, to dissolve in a solvent, to have a polar property, and to exhibit electrochromism, and to prepare such a substance. A method and a color-developing / discoloring material using the substance. Further, the object of the present invention is to form a film on a large area, and further, to produce a color by using electrochromism which is excellent in adhesive strength to electrodes and the like.
It is to provide a color-changing material at low cost.

[0005]

According to the present invention, in order to achieve the above object, the following chemical formula 4

[Chemical 4] (In the formula, R is a group based on a polymer or a copolymer having electrical conductivity and exhibiting a color or a color change by oxidation or reduction, and L, M, and N are each 1 ≦ L ≦ (NM). 1 ≦
An integer of M ≦ (N−L), and N is an integer of 10 to 12,000. An etherified vinyl alcohol-based polymer represented by the general formula (1) is provided. The etherified vinyl alcohol-based polymer is a group based on the general formula RX (in the formula, R is a polymer or copolymer showing coloration or discoloration by oxidation or reduction, and X represents chlorine, bromine, or iodine). It can be easily obtained by reacting a halogen compound represented by () with a vinyl alcohol polymer. Further according to the present invention, containing an etherified vinyl alcohol-based polymer represented by the general formula (1),
There is also provided a color-developing / color-changing material which is characterized in that it develops or changes color by oxidation or reduction of the etherified vinyl alcohol polymer.

[0006]

The color display material obtained according to the present invention is a vinyl alcohol polymer (hereinafter abbreviated as PVA) which has electrical conductivity and is colored by adding an electron acceptor. It is characterized in that a polymer and a copolymer (hereinafter, abbreviated as a color former) exhibiting discoloration are grafted. PVA belongs to the most polar class of synthetic polymer substances and is soluble in polar solvents such as water, dimethylformamide, and dimethylsulfoxide. By grafting a coloring material as a side chain onto such PVA, a novel coloring / discoloring material that retains the properties of PVA having a high polarity as it is can be obtained. PVA is also known as an organic solid electrolyte and has a property of dissolving ionic salts well.
In PVA, the ionic salts dissociate into anions and cations, and the dissociated ions migrate in their respective directions by applying an electric field. In this way, ions can move in PVA, and the property is inherited by the coloring / discoloring material.

The reaction of the OH group of PVA with an organic halide is applied to the introduction of the color-forming material into PVA via an ether bond. For example, it can be performed using the Williamson Ether synthesis method. The Williamson ether synthesis method is known as a reaction of an alkoxide or phenoxide with an alkyl halide and is often used for the synthesis of ether. First, halogen (F, Cl, Br,
A polymer or copolymer having I) and exhibiting color / discoloration by oxidation or reduction is synthesized, and then reacted with PVA by the Williamson Ether synthesis method to obtain a target color / discoloration material. can get. For example, 2,5
-Dibromothiophene is obtained by dehalogenating magnesium with magnesium in the presence of a transition metal catalyst (JP-A-58-1).
See Japanese Patent No. 47426 for details. Polythiophene or thiophene oligomer is
When the number of moles of magnesium is smaller than the number of moles of 2,5-dibromothiophene, the compound has bromine at the terminal as shown in the following reaction formula.

[Chemical 5]

Therefore, when a polythiophene or thiophene oligomer having bromine at its terminal is reacted with PVA, a polymer having a group based on polythiophene or thiophene oligomer can be obtained as shown in the reaction formula below. You can

[Chemical 6] Since polythiophene and thiophene oligomer are discolored by oxidation or reduction, the color-changing / color-changing group for the purpose of the present invention is stable on the side chain of PVA which gives a good polymer solid electrolyte and has good adhesiveness, which is an ether bond. A material exhibiting good electrochromic coloration / discoloration introduced by bonding is obtained.

The proportion of the above-mentioned coloring material and color-changing group introduced into PVA is 0.01 to 30% of the -OH group of PVA.
Is preferably substituted, and 0.1 to 10% is particularly preferable. As an organic halide for introducing a side chain having a color-developing / discoloring ability into the PVA side chain, in addition to the above polythiophene or thiophene oligomer, a benzene oligomer having a halogen at a terminal, a 3-alkylthiophene oligomer, 3- Alkoxy thiophene oligomer,
A π-conjugated conductive polymer having a halogen such as a pyridine oligomer, a quinoline oligomer, a pyrrole oligomer, or an N-substituted pyrrole oligomer can be used. The degree of polymerization of PVA used is not particularly limited, but is preferably 10 to 12,000 in consideration of easiness of reaction, solubility in a solvent, film strength after film formation, and the like. 20-1,500 is preferable. The color-developing / discoloring material thus obtained is prepared by preparing a dimethyl sulfoxide solution having a concentration of 0.1 to 5% in the same manner as in ordinary PVA, casting the solution on a glass plate, and heating it at a temperature of about 70 ° C. for about 10 hours. A film can be formed by drying under reduced pressure.

[0010]

EXAMPLES The present invention will be specifically described below with reference to examples, but it goes without saying that the present invention is not limited to the following examples. Example 1 PV having a degree of polymerization of 7000 in 20 mL of dimethyl sulfoxide
Add 0.11 g of A and heat to 80 ° C. with stirring to completely dissolve. Then, add 0.08g of KOH, and 80 ℃
While stirring at 0.5 g of polythiophene having bromine at the end, 0.29 g of cuprous iodide (CuI) and 0.11 g of potassium iodide (KI) were added, and the mixture was stirred and reacted at 80 ° C. for 5 hours. Then, the mixture was put into cold water to stop the reaction, filtered, washed, and dried to synthesize PVA having polythiophene as a side chain. The obtained polymer was light reddish brown. The obtained polymer was dissolved in dimethylsulfoxide, formed into a film, and then immersed in an aqueous sulfuric acid solution, whereupon it turned blue. When the aqueous solution was changed to a sodium hydroxide solution, the blue color disappeared and the original light reddish brown color was restored.

Example 2 1.07 g of PVA having a degree of polymerization of 570 was added to 20 mL of tetrahydrofuran and dispersed. To this solution, 3.5 mL of a 680 mmol / L sodium naphthalide solution was added dropwise, and thiophene oligomer-0.49 having bromine at the end was added.
9 g and 0.11 g of cuprous iodide (CuI) were added, and the mixture was refluxed for 3 hours. The reaction solution was poured into toluene and washed.
After removing the supernatant, dissolve in dimethyl sulfoxide,
The precipitate was removed by centrifugation. The supernatant was dropped into toluene for reprecipitation. After removing toluene under reduced pressure,
It was dissolved in dimethylsulfoxide, formed into a film on an ITO glass plate, and dried under reduced pressure to obtain a thin yellowish brown polymer film. The ITO glass plate coated with the obtained light yellowish brown polymer film was placed in an electrolytic solution (tetraethylammonium perchlorate / acetonitrile 0.1 mol / L) at a voltage of +2.0 V with a platinum plate as a counter electrode. -Pinging showed a red color. When de-doping was performed at -2.0 V, the color changed to a light yellowish brown similar to that during film formation.

Example 3 0.5 g of PVA having a degree of polymerization of 3000 was dissolved in a potassium hydroxide solution prepared by dissolving 5 g of potassium hydroxide in 8 g of water, and 0.1 g of thiophene oligomer having iodine at the end was dissolved in 5 mL of toluene. The solution was added and mixed and stirred.
Add 2 g of potassium hydroxide and 0.114 g of cuprous oxide,
The reaction was carried out at 90 ° C for 10 hours. After the reaction, the product was washed with methanol containing hydrochloric acid, filtered, dissolved in dimethylsulfoxide, filtered to remove impurities, and reprecipitated with toluene.
A reddish brown polymer was obtained. The obtained polymer was dissolved in dimethyl sulfoxide, cast on ITO glass to form a film, and an ITO electrode coated with a red polymer was obtained. The obtained electrode was subjected to doping at +2.0 V in an electrolytic solution (lithium perchlorate / propylene carbonate 0.1 mol / L) with a platinum electrode as a counter electrode, and the polymer film turned dark blue. did. When the voltage was inverted and the doping was performed at -2 V, the polymer film turned red again.

[0013]

INDUSTRIAL APPLICABILITY As described above, the color display material obtained by the present invention belongs to the most polar class among synthetic polymer substances, is soluble in polar solvents such as water, dimethylformamide and dimethylsulfoxide, and Also known as organic solid electrolytes, vinyl alcohol-based polymers that have the property of dissolving ionic salts satisfactorily have electrical conductivity as a side chain, and develop color / discoloration by adding an electron acceptor. Since it is composed of an etherified vinyl alcohol-based polymer grafted with the polymer and copolymer shown below, P having a high polarity
It inherits the properties of VA as it is, and is excellent in color development and discoloration, as well as in adhesive strength to electrodes. Also,
The etherified vinyl alcohol-based polymer of the present invention can be easily produced by the Williamson ether synthesis method, can provide a coloring / discoloring material using electrochromism at low cost, and can form a film on a large area by a method such as casting. It is possible. Therefore, it can be said that the material is extremely practical and advantageous as a material for the electrochromic display element.

Claims (3)

[Claims] 1. The following chemical formula 1 (In the formula, R is a group based on a polymer or a copolymer having electrical conductivity and exhibiting a color or a color change by oxidation or reduction, and L, M, and N are each 1 ≦ L ≦ (NM). 1 ≦
An integer of M ≦ (N−L), and N is an integer of 10 to 12,000. ) An etherified vinyl alcohol polymer represented by: 2. A compound represented by the general formula RX (in the formula, R is a group based on a polymer or a copolymer that exhibits coloration or discoloration by oxidation or reduction, and X represents chlorine, bromine, or iodine). By reacting a halogen compound with a vinyl alcohol polymer, the following chemical formula 2 (In the formula, R is a group based on a polymer or a copolymer having electrical conductivity and exhibiting a color or a color change by oxidation or reduction, and L, M, and N are each 1 ≦ L ≦ (NM). 1 ≦
An integer of M ≦ (N−L), and N is an integer of 10 to 12,000. ) The etherified vinyl alcohol-based polymer represented by the formula (1) is obtained. 3. The following chemical formula 3 (In the formula, R is a group based on a polymer or a copolymer having electrical conductivity and exhibiting a color or a color change by oxidation or reduction, and L, M, and N are each 1 ≦ L ≦ (NM). 1 ≦
An integer of M ≦ (N−L), and N is an integer of 10 to 12,000. ) A color-forming / color-changing material containing an etherified vinyl alcohol-based polymer represented by the formula (1), which develops or changes color by oxidation or reduction of the etherified vinyl alcohol-based polymer.