JP2014095032A - Conductive polymer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive material that can be formed into a film by a simple method and also has good conductivity.SOLUTION: A complex obtained by complexing of polythiophene having a repeating unit represented by the formula (1), and anionic polysaccharide is superior in film forming properties and conductivity, and can be used as conductive materials.

Description

  The present invention relates to a conductive material that can be formed by a simple technique and has excellent conductivity, and a method for manufacturing the same.

  In recent years, with the development of “photoelectric conversion devices” such as solar cells and organic EL, there is an increasing need for transparent electrodes having both conductivity and transparency. Currently, indium tin oxide (ITO) electrodes are commonly used. However, since ITO electrodes are made by vacuum sputtering, they are expensive, unsuitable for large areas, and lack flexibility. It was difficult to make flexible electrodes.

  In addition, indium, the main raw material, is a rare metal that has problems such as resource depletion and price increases, and therefore, conductive polymers have been vigorously developed as an alternative material. In order to realize a sustainable society, it is necessary to consider the reduction of environmental load, and a conductive material having functions such as environmental compatibility as well as high performance characteristics is desired. The conductive polymer can be applied by atmospheric pressure, and a flexible electrode having a large area can be produced at low cost.

  Conventionally, among conductive polymers, PEDOT / PSS in which polystyrene sulfonic acid (PSS) is added to poly (3,4-ethylenedioxythiophene) (PEDOT) as a dopant for flowing electricity has attracted attention. Since 3,4-ethylenedioxythiophene (EDOT) has a low water solubility of 2.1 g / L at 20 ° C., it is polymerized using an oxidizing agent in an aqueous solvent in which polystyrenesulfonic acid is dissolved. Thus, it is obtained in the state of a water dispersible PEDOT / PSS complex. PEDOT / PSS is relatively stable and has good durability, but it has low conductivity compared to existing ITO electrodes. Therefore, it is desirable to develop a conductive material with higher conductivity by simple operation. It was.

  So far, several improved techniques for improving the conductivity of PEDOT / PSS have been reported. For example, Patent Document 1 discloses that conductivity is improved when a film is formed by adding a sulfoxide solvent, a polyhydric alcohol, a polyol, or the like to an aqueous dispersion of PEDOT / PSS. However, even the technique of Patent Document 1 cannot provide sufficient conductivity to PEDOT / PSS.

  Patent Document 2 discloses an example in which a sugar alcohol is added to PEDOT / PSS to improve the conductive performance. However, in the technique of Patent Document 2, a PEDOT / PSS complex is prepared by polymerizing EDOT using an oxidizing agent in the presence of PSS, and a sugar alcohol (arabitol is further added to the solid content of PEDOT / PSS. ) Is added and 60% is required to dry and heat, and the film forming process is complicated and unsuitable for industrial production.

  As described above, the conventional conductive material has drawbacks such as low conductivity and the necessity of mixing a large amount of components such as a binder, and there are barriers to commercialization.

Special table 2006-520994 gazette JP 2012-46605 A

  An object of the present invention is to provide a conductive material that can be formed by a simple technique and has excellent conductivity.

  As a result of intensive studies in view of such circumstances, the present inventors have found that a polythiophene having a repeating unit represented by the formula (1) (hereinafter sometimes simply referred to as “polythiophene”) and an anionic polysaccharide It has been found that the composite obtained by combining is excellent in film-forming property and conductivity, and can be suitably used as a conductive material. The present invention has been completed by further studies based on such knowledge.

That is, this invention provides the invention of the aspect hung up below.
Item 1. Polythiophene having a repeating unit represented by the formula (1);
[In formula (1), R ¹ and R ² are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms, R ¹ and R ² linked And a C 1-8 dioxyalkylene group, an aromatic ring or a 3-7 membered alicyclic ring. ]
A conductive material comprising a complex with an anionic polysaccharide.
Item 2. Item 2. The conductive material according to Item 1, wherein the anionic polysaccharide is a sulfated polysaccharide.
Item 3. The sulfated cellulose in which the anionic polysaccharide has a repeating unit represented by the formula (2),
[In Formula (2), R < ³ > -R < ⁸ > represents a hydrogen atom, a sulfonic acid group, or a C1-C6 alkylsulfonic acid group each independently, and at least 1 is a sulfonic acid group or C1-C1. 6 alkylsulfonic acid groups are represented. ]
Sulfated starch having a repeating unit represented by formula (3),
Wherein (3), R ⁹ ~R ¹⁴ each independently represent a hydrogen atom, a sulfonic acid group or alkyl sulfonic acid having 1 to 6 carbon atoms and at least one sulfonic acid group or 1 carbon atoms 6 alkylsulfonic acid groups are represented. ]
And sulfated starch having a repeating unit represented by formula (4)
Wherein (4), R ¹⁵ ~R ²² each independently represent a hydrogen atom, a sulfonic acid group or alkyl sulfonic acid having 1 to 6 carbon atoms, and at least one sulfonic acid group or 1 carbon atoms 6 alkylsulfonic acid groups are represented. ]
Item 3. The conductive material according to Item 1 or 2, which is at least one sulfated polysaccharide selected from the group consisting of:
Item 4. Item 4. The conductive material according to any one of Items 1 to 3, wherein the number of introduced anionic groups in the anionic polysaccharide is 0.3 to 3 per residue of the constituent monosaccharide.
Item 5. Thiophene represented by formula (5) in the presence of an anionic polysaccharide, a solvent and an oxidizing agent
[In Formula (5), R < ¹ > and R < ² > are the same as the above. ]
A method for producing a complex of polythiophene and a sulfated polysaccharide, characterized by subjecting oxidative polymerization of
Item 6. Item 5. A conductive film containing the conductive material according to any one of Items 1 to 4.
Item 7. Item 5. A conductive member obtained by forming the conductive material according to any one of Items 1 to 4 on a substrate.

  The conductive material of the present invention has excellent conductivity, and is useful as an electrode material or a wiring material in a photoelectric conversion device such as a solar cell or an organic EL. In addition, the conductive material of the present invention has excellent film forming properties, and can be formed by a simple method without mixing a large amount of components such as a binder. The member can be manufactured by an easy method.

  In addition, according to the production method of the present invention, since a complex of polythiophene and anionic polysaccharide is obtained in the state of dispersion, high conductivity can be obtained by a simple method of coating the dispersion and forming a film. It becomes possible to produce the conductive member.

It is a figure which shows the result of having carried out FT-IR measurement of the sulfated cellulose I and II used in Examples 1-2. It is a figure which shows the result of having carried out FT-IR measurement of the sulfated starch used in Example 3. FIG.

  The conductive material of the present invention is a complex of a polythiophene having a repeating unit represented by formula (1) and an anionic polysaccharide (hereinafter sometimes referred to as “polythiophene / anionic polysaccharide complex”). It is characterized by comprising. Hereinafter, the conductive material of the present invention will be described in detail.

Polythiophene The polythiophene used in the present invention has a repeating unit represented by the following formula (1).

In formula (1), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms, or R ¹ and R ² are linked, It represents a C 1-8 dioxyalkylene group, an aromatic ring or a 3-7 membered alicyclic ring.

  The alkyl group having 1 to 8 carbon atoms may be linear or branched. As said C1-C8 alkyl group, Preferably a C1-C6 alkyl group is mentioned.

  Moreover, as said C1-C8 alkoxy group, either linear or branched may be sufficient. As said C1-C8 alkoxy group, Preferably a C1-C6 alkoxy group is mentioned.

In addition, when R ¹ and R ² are linked to form a dioxyalkylene group having 1 to 8 carbon atoms, the carbon number of the dioxyalkylene group is preferably 1 to 6 carbon atoms, more preferably 2 carbon atoms. ~ 4.

In addition, when R ¹ and R ² are connected to form a 3- to 7-membered alicyclic ring, the alicyclic ring is preferably a 4- to 7-membered ring, more preferably a 5- to 6-membered ring. A ring is mentioned.

  Although it does not restrict | limit especially about the number of the repeating units represented by Formula (1) which forms polythiophene, For example, about 2-50 is mentioned.

  As a monomer compound which comprises the repeating unit represented by Formula (1), Preferably, the C1-C8 alkyl group and / or carbon number are respectively independently in 3rd-position and 4th-position of a thiophene skeleton. Compounds having 1 to 8 alkoxy groups substituted; 3,4-disubstituted thiophenes in which dioxyalkylene groups having 1 to 8 carbon atoms are formed at the 3rd and 4th positions of the thiophene skeleton. More specifically, 3,4-dialkylthiophene, 3,4-dialkoxythiophene, 3,4-alkylenedioxythiophene and the like can be mentioned. Among these, 3,4-alkylenedioxythiophene is preferable.

  Preferable specific examples of the monomer compound constituting the repeating unit represented by the formula (1) include, for example, 3,4-dihexylthiophene, 3,4-diethylthiophene, 3,4-dipropylthiophene, 3 , 4-dimethoxythiophene, 3,4-diethoxythiophene, 3,4-dipropoxythiophene, 3,4-dibutoxythiophene, 3,4-methylenedioxythiophene, 3,4-ethylenedioxythiophene, 3, 4-propylene dioxythiophene etc. are mentioned. Among these, 3,4-ethylenedioxythiophene is preferable.

Anionic polysaccharide The anionic polysaccharide used in the present invention is a polysaccharide into which an anionic group has been introduced. Examples of the anionic group include a sulfonic acid group, an alkyl sulfonic acid group having 1 to 6 carbon atoms, a carboxyl group, and a phosphoric acid group. Among these anionic groups, a sulfonic acid group and an alkylsulfonic acid group having 1 to 6 carbon atoms are preferable.

  In the anionic polysaccharide, examples of the polysaccharide into which the anionic group is introduced include starches, alginic acids, celluloses, and gums.

  The anionic polysaccharide used in the present invention may be a polysaccharide that already has an anionic group in nature, or may be a polysaccharide to which an anionic group has been artificially added.

  The number of constituent monosaccharides in the anionic polysaccharide is not particularly limited, but from the viewpoint of further stably forming a complex with the polythiophene and further improving conductivity and film-forming property, for example, 10 to 15000. , Preferably 20-2000 is mentioned.

  The number of anionic groups in the anionic polysaccharide is not particularly limited, but from the viewpoint of providing even more excellent conductivity, 0.3 to 3, preferably 0.4 to 1 residue per constituent monosaccharide. 2.8, more preferably 1 to 2.5.

  As the anionic polysaccharide, from the viewpoint of further improving the conductivity and film-forming property, it is preferably a sulfated polysaccharide (that is, a polysaccharide having a sulfonic acid group and / or an alkylsulfonic acid group having 1 to 6 carbon atoms). ). Specific examples of sulfated polysaccharides include sulfates such as chitin, chitosan, starch, cellulose, guar gum, gum arabic, glucomannan, agar agarose, amylose, amylopectin, alginic acid, etc .; natural fucoidan, chondroitin sulfate, porphyran And sulfated polysaccharides. Among these sulfated polysaccharides, preferred are sulfated cellulose and sulfated starch. More specifically, sulfated cellulose having a repeating unit represented by the following formula (2), the following formula (3 ) Or sulfated starch having a repeating unit represented by (4) is exemplified. In addition, since starch is a mixture of amylose and amylopectin, what sulfated starch is the sulfated amylose which has a repeating unit represented by the following Formula (3), and the repeating unit represented by the following Formula (4) A mixture of sulfated amylopectin having

In formula (2), R ^{3 to} R ⁸ each independently represent a hydrogen atom, a sulfonic acid group, or an alkylsulfonic acid group having 1 to 6 carbon atoms, and at least one of them is a sulfonic acid group or 1 to carbon atoms. 6 alkylsulfonic acid groups are represented. As carbon number of the said alkylsulfonic acid group, Preferably it is 1-5, More preferably, it is 1-4, Most preferably, 1-3 is mentioned.

In formula (3), R ^{9 to} R ¹⁴ each independently represent a hydrogen atom, a sulfonic acid group, or an alkylsulfonic acid group having 1 to 6 carbon atoms, and at least one of them is a sulfonic acid group or 1 to carbon atoms. 6 alkylsulfonic acid groups are represented. As carbon number of the said alkylsulfonic acid group, Preferably it is 1-5, More preferably, it is 1-4, Most preferably, 1-3 is mentioned.

In the formula (4), R ^{15 to} R ²² each independently represent a hydrogen atom, a sulfonic acid group, or an alkylsulfonic acid group having 1 to 6 carbon atoms, and at least one of them is a sulfonic acid group or 1 to carbon atoms. 6 alkylsulfonic acid groups are represented. As carbon number of the said alkylsulfonic acid group, Preferably it is 1-5, More preferably, it is 1-4, Most preferably, 1-3 is mentioned.

  In addition, in the sulfated starch which has a repeating unit represented by Formula (4), the repeating unit represented by Formula (4) forms a branched structure part, and is between the repeating units represented by Formula (4). May adopt a structure in which one or more repeating units represented by the formula (3) are inserted.

  These anionic polysaccharides may be used individually by 1 type, and may be used in combination of 2 or more type.

  As the anionic polysaccharide, a commercially available product may be used, or it may be obtained according to a known production method. For example, in order to introduce a sulfonic acid group into a polysaccharide, for example, sulfamic acid, halogenosulfonic acid or the like may be reacted with the polysaccharide, and an alkylsulfonic acid group having 1 to 6 carbon atoms may be introduced into the polysaccharide. For example, a halogenated alkylsulfonic acid having 1 to 6 carbon atoms may be reacted with a polysaccharide.

Polythiophene / anionic polysaccharide complex The polythiophene / anionic polysaccharide complex is produced by oxidative polymerization of thiophene represented by the following formula (5) in the presence of an anionic polysaccharide, a solvent and an oxidizing agent. The

In formula (5), R ¹ and R ² are the same as described above.

  Specifically, a polythiophene / anionic polysaccharide complex is obtained by polymerizing thiophene by adding a thiophene represented by the formula (5) and an oxidizing agent to a solution in which an anionic polysaccharide is previously dissolved in a solvent. Obtained in the state of a dispersion solution. In the polythiophene / anionic polysaccharide complex thus obtained, the binding mode between the polythiophene and the anionic polysaccharide complex is not desired to be limited, but the polythiophene / anionic polysaccharide complex formed by the polymerization reaction is not desired. It is thought that it is complexed in a state in which the saccharide anion is doped.

  As the thiophene represented by the formula (5), preferably, an alkyl group having 1 to 8 carbon atoms and / or an alkoxy group having 1 to 8 carbon atoms is independently substituted at the 3-position and 4-position of the thiophene skeleton. Thiophene; 3,4-disubstituted thiophene in which a dioxyalkylene group having 1 to 8 carbon atoms is formed at the 3rd and 4th positions of the thiophene skeleton. More specifically, 3,4-dialkylthiophene, 3,4-dialkoxythiophene, 3,4-alkylenedioxythiophene and the like can be mentioned. Among these, 3,4-alkylenedioxythiophene is preferable.

  As preferable specific examples of the thiophene represented by the formula (5), for example, 3,4-dihexylthiophene, 3,4-diethylthiophene, 3,4-dipropylthiophene, 3,4-dimethoxythiophene, 3, 4-diethoxythiophene, 3,4-dipropoxythiophene, 3,4-dibutoxythiophene, 3,4-methylenedioxythiophene, 3,4-ethylenedioxythiophene, 3,4-propylenedioxythiophene, etc. Can be mentioned. Among these, 3,4-ethylenedioxythiophene is preferable.

  In the polythiophene / anionic polysaccharide complex, the ratio of polythiophene and anionic polysaccharide is not particularly limited, but the higher the ratio of polythiophene, the higher the conductivity, but the tendency to decrease dispersibility. Is appropriately set according to the type of polythiophene or anionic polysaccharide. Specifically, the mass ratio of polythiophene and anionic polysaccharide is 1: 0.5 to 1: 8, preferably 1: 1 to 1: 4. By satisfying such a mass ratio, the dispersibility in the solvent can be improved while providing more excellent conductivity.

  In the production of the polythiophene / anionic polysaccharide complex, the amount of the thiophene and the anionic polysaccharide represented by the formula (5) used as the raw material compound satisfies the above-mentioned ratio of the polythiophene and the anionic polysaccharide. What is necessary is just to set suitably in the possible range. Specifically, the thiophene represented by the formula (5) is 12.5 to 400 parts by mass, preferably 25 to 200 parts by mass, per 100 parts by mass of the anionic polysaccharide.

  The oxidizing agent used in the production of the polythiophene / anionic polysaccharide complex is not particularly limited as long as the thiophene represented by the formula (5) can be oxidatively polymerized, and examples thereof include peroxodisulfuric acid, peroxo Sodium disulfate, potassium peroxodisulfate, ammonium peroxodisulfate, inorganic ferric oxide, organic ferric oxide, hydrogen peroxide, potassium permanganate, potassium dichromate, alkali perborate, iron sulfate ( III), iron chloride (III) and the like. Among these, Preferably, peroxodisulfuric acid, sodium peroxodisulfate, potassium peroxodisulfate, ammonium peroxodisulfate, iron (III) sulfate, and iron (III) chloride are mentioned. These oxidizing agents may be used individually by 1 type, and may be used in combination of 2 or more type.

  In the production of the polythiophene / anionic polysaccharide complex, the amount of the oxidizing agent used is not particularly limited, but for example, 0.1 to 5 equivalents, preferably 0, per 1 mol of thiophene represented by the formula (5). 3 to 2 equivalents.

  The solvent used for the production of the polythiophene / anionic polysaccharide complex is not particularly limited as long as it can dissolve the anionic polysaccharide complex and can carry out the polymerization reaction of thiophene. Preferably, water is used. Further, as the solvent, an aqueous solvent obtained by mixing a lower alcohol such as methanol or ethanol or a polar organic solvent such as acetone or acetonitrile with water may be used. These solvents may be used individually by 1 type, and may be used in combination of 2 or more type.

  In the production of the polythiophene / anionic polysaccharide complex, the amount of the solvent used is not particularly limited, but is, for example, 1000 to 50000 ml, preferably 3000 to 30000 ml per mole of thiophene represented by the formula (5). Can be mentioned.

  The reaction time and reaction temperature in the production of the polythiophene / anionic polysaccharide complex are appropriately set according to the type of thiophene or anionic polysaccharide used as the raw material compound, the type of oxidizing agent, etc. It is -90 degreeC, Preferably it is 20-80 degreeC, 1 to 96 hours, Preferably it is 5 to 48 hours.

  By polymerizing the thiophene represented by the formula (5) in the presence of the anionic polysaccharide as described above, a polythiophene / sulfated polysaccharide complex dispersion solution can be obtained. The polythiophene / sulfated polysaccharide complex thus obtained is used for the production of a conductive film in the state of a dispersion obtained after the reaction, or after separation and purification of the polythiophene / sulfated polysaccharide complex as necessary. be able to.

Conductive film using polythiophene / sulfated polysaccharide complex Polythiophene / anionic polysaccharide complex has excellent conductivity and film-forming properties, so it can be used as a conductive film by forming a film on a substrate. be able to.

  Specifically, a conductive film using a polythiophene / anionic polysaccharide complex is dried after a dispersion containing the polythiophene / anionic polysaccharide complex is applied on the entire surface of the substrate or in a predetermined shape. And is produced by removing the solvent.

  The method for applying the dispersion containing the polythiophene / anionic polysaccharide complex to the substrate is not particularly limited. For example, spray coating method, spin coating method, blade coating method, dip coating method, casting method, roll coating method. And wet processes such as a method by coating such as a bar coating method and a die coating method; a method by patterning such as printing and inkjet. Among these, a spin coating method and a casting method are preferable.

  The drying method is not particularly limited, and examples thereof include heat drying, freeze drying, reduced pressure drying, hot air drying, and supercritical drying. The drying temperature is appropriately set according to the drying method. 50 to 250 degreeC, Preferably 60 to 150 degreeC is mentioned. By setting the drying temperature to 250 ° C. or lower, it is possible to effectively suppress the decrease in the conductivity of the polythiophene / anionic polysaccharide complex during drying.

  Examples of the substrate used for forming the polythiophene / anionic polysaccharide complex include a glass plate, a plastic sheet, and a plastic film. Examples of the plastic include polyester, polyethylene, polypropylene, polystyrene, polyimide, polyamide, polyethylene terephthalate, polyethylene naphthalate, epoxy resin, chlorine resin, silicon resin, and blends thereof.

  A conductive film obtained by forming a polythiophene / anionic polysaccharide complex, and a substrate provided with the conductive film include an antistatic film, wiring for an electronic device typified by an organic EL or a solar cell, an electrode material, etc. Used as a conductive member.

  EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

1. Production of polythiophene / sulfated polysaccharide complex (Example 1)
2.00 g of cellulose (trade name “Cellulose, fibers”, manufactured by Sigma) was added to 100 ml of N, N-dimethylformamide (DMF) and stirred for 14 hours or more. Next, a solution obtained by dissolving 1.85 ml of chlorosulfonic acid in 30 ml of DMF was slowly added over 30 minutes. Stir at 50 ° C. for 5 hours. The reaction solution was added to a saturated sodium acetate ethanol solution, and the precipitate was collected and washed with ethanol. The precipitate was dissolved in water and dialyzed, and then lyophilized to obtain 1.4 g of sulfated cellulose (sulfated cellulose I). The result of FT-IR measurement is shown in FIG. As a result of elemental analysis, the sulfone group introduction rate (DS value) per glucose unit was 1.28.

  Sulfated cellulose I (0.20 g) was dissolved in water (20 ml), EDOT (0.10 g), potassium peroxodisulfate (0.13 g) and iron (III) sulfate (0.50 mg) were added, and the mixture was stirred at room temperature for 24 hours to carry out the reaction. Subsequently, dialysis and concentration were sequentially performed to obtain a dispersion of PEDOT / sulfated cellulose I complex having a solid content of 1.30% by mass.

(Example 2)
When an elemental analysis of cellulose sulfate (sulfated cellulose II) manufactured by ACROS was performed, the DS value was 2.75. The result of FT-IR measurement is shown in FIG.

  Sulfated cellulose II (0.20 g) was dissolved in water (20 ml), EDOT (0.10 g), potassium peroxodisulfate (0.13 g) and iron (III) sulfate (0.50 mg) were added, and the mixture was stirred at room temperature for 24 hours to carry out the reaction. Subsequently, dialysis and concentration were sequentially performed to obtain a dispersion of PEDOT / sulfated cellulose II composite having a solid content of 1.30% by mass.

(Example 3)
2.00 g of starch (trade name “starch (soluble)”, manufactured by Wako Pure Chemical Industries, Ltd.) was added to 100 ml of DMF and stirred for 14 hours or more. A solution prepared by dissolving 3.70 ml of chlorosulfonic acid in 30 ml of DMF was slowly added over 30 minutes. Then, it reacted by stirring for 5 hours at 50 degreeC. The reaction solution was added to a saturated sodium acetate ethanol solution, and the precipitate was collected and washed with ethanol. The precipitate was dissolved in water and dialyzed, and then freeze-dried to obtain 1.6 g of sulfated starch. As a result of elemental analysis, the DS value was 1.89. The result of FT-IR measurement is shown in FIG.

  0.20 g of sulfated starch was dissolved in 20 ml of water, 0.10 g of EDOT, 0.13 g of potassium peroxodisulfate and 0.50 mg of iron (III) sulfate were added, and the mixture was stirred at room temperature for 24 hours to carry out the reaction. Subsequently, dialysis and concentration were sequentially performed to obtain a dispersion of PEDOT / sulfated starch complex having a solid content of 1.30% by weight.

2. Preparation of conductive film using polythiophene / sulfated polysaccharide composite 300 μl of PEDOT / sulfated polysaccharide dispersion obtained in Examples 1 to 3 was cast on glass and dried by heating at 80 ° C. for 1 hour. By doing so, a conductive film of PEDOT / sulfated polysaccharide complex was produced. For comparison, a conductive film was prepared in the same manner using a commercially available aqueous dispersion of PEDOT / PSS composite (manufactured by Aldrich) (Comparative Example 1).

3. Performance Evaluation of Conductive Film Sheet resistance was measured for the produced conductive film. Specifically, the sheet resistance was measured by connecting a 4-probe probe (PSP, manufactured by Mitsubishi Chemical) to a resistivity meter (Loresta GP, manufactured by Mitsubishi Chemical) and pressing the membrane against the 4-probe probe. . Table 1 shows the sheet resistance measurement results.

  From the above results, the conductive film using the PEDOT / sulfated polysaccharide complex of Examples 1 to 3 has much higher conductivity than the conductive film using the conventional PEDOT / PSS complex. Became clear. Moreover, the PEDOT / sulfated polysaccharide complex of Examples 1 to 3 could be easily formed into a conductive film, and the film forming property was very good.

Claims (7)

Polythiophene having a repeating unit represented by the formula (1);
[In formula (1), R ¹ and R ² are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms, R ¹ and R ² linked And a C 1-8 dioxyalkylene group, an aromatic ring or a 3-7 membered alicyclic ring. ]
A conductive material comprising a complex with an anionic polysaccharide.   The conductive material according to claim 1, wherein the anionic polysaccharide is a sulfated polysaccharide. The sulfated cellulose in which the anionic polysaccharide has a repeating unit represented by the formula (2),
[In Formula (2), R < ³ > -R < ⁸ > represents a hydrogen atom, a sulfonic acid group, or a C1-C6 alkylsulfonic acid group each independently, and at least 1 is a sulfonic acid group or C1-C1. 6 alkylsulfonic acid groups are represented. ]
Sulfated starch having a repeating unit represented by formula (3),
Wherein (3), R ⁹ ~R ¹⁴ each independently represent a hydrogen atom, a sulfonic acid group or alkyl sulfonic acid having 1 to 6 carbon atoms, and at least one sulfonic acid group or 1 carbon atoms 6 alkylsulfonic acid groups are represented. ]
And sulfated starch having a repeating unit represented by formula (4)
Wherein (4), R ¹⁵ ~R ²² each independently represent a hydrogen atom, a sulfonic acid group or alkyl sulfonic acid having 1 to 6 carbon atoms, and at least one sulfonic acid group or 1 carbon atoms 6 alkylsulfonic acid groups are represented. ]
The conductive material according to claim 1 or 2, which is at least one sulfated polysaccharide selected from the group consisting of:   The conductive material according to claim 1, wherein the number of introduced anionic groups in the anionic polysaccharide is 0.3 to 3 per residue of the constituent monosaccharide. Thiophene represented by formula (5) in the presence of an anionic polysaccharide, a solvent and an oxidizing agent
[In Formula (5), R < ¹ > and R < ² > are the same as the above. ]
A method for producing a complex of polythiophene and a sulfated polysaccharide, characterized by subjecting oxidative polymerization of   The electrically conductive film containing the electroconductive material in any one of Claims 1-4.   The electroconductive member formed by forming the electroconductive material in any one of Claims 1-4 on a board | substrate.