JP2009221417A - Electroconductive polymer and its refining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electroconductive polymer having an improved durability including stability against light irradiation by effectively removing metal ions left in the electroconductive polymer synthesized by oxidation polymerization and a method of refining the polymer. <P>SOLUTION: The electroconductive polymer contains high molecular compounds and has an iron ion content in the range of 0.1-10 ppm mass%. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a conductive polymer and a purification method thereof.

  In recent years, liquid crystal displays (LCDs), plasma displays (PDPs), and image display bodies (displays) represented by electroluminescence (EL) elements have been used in various fields such as televisions, computers, and various mobile devices that have become popular in recent years. It has become widely used in and has made remarkable progress. In addition, as part of defossil energy in consideration of the global environment, there is an increasing demand for the spread of solar cells with higher functionality. In such display elements and solar cells, conductive films are used.

  As the conductive film, for example, a conductive film using a metal-based material such as an ITO-based conductive film is used, and these include a metal-based material on a glass substrate such as a vacuum deposition method or a sputtering method. In general, the film is produced by a phase method. In addition, with respect to display elements such as mobile phones and mobiles, the weight reduction in grams has been promoted, and the current situation is that the display element substrate is also required to shift from glass to plastic. With the introduction of the plastic substrate, the weight of the display element is less than half that of the conventional one, and the strength and impact resistance can be remarkably improved. However, the ITO conductive film has a problem that the adhesiveness is lowered by replacing the glass substrate with the plastic film, and the base material and the formed conductive film are easily peeled off. In addition, since metal-based materials such as ITO are usually formed using a vapor phase method such as sputtering, a large amount of cost is required for a manufacturing apparatus.

  It is known to use a conductive polymer as an alternative conductive material. By using a conductive polymer, it is possible to form a thin film that exhibits conductivity by coating, and there is an advantage that it can be manufactured at low cost. In addition, an electrode made of a conductive polymer is considerably more flexible than an ITO electrode, is less brittle, and is difficult to break even when used for a flexible material, so a touch screen that requires a highly flexible electrode. In addition, the manufacturing of the apparatus has an advantage that the life of the apparatus can be extended.

  A π-conjugated polymer (conjugated polymer) is useful as the conductive polymer. However, as a conductive film using the π-conjugated polymer, a technique using polythiophene containing a polyanion for the production of a conductive film is disclosed. (For example, refer to Patent Document 1). However, it has become clear that these known conductive films are somewhat weaker in durability than ITO films and the like, and it is impossible to achieve practically sufficient durability for specific applications.

In addition, when the above π-conjugated polymer is synthesized by an oxidative polymerization method, iron ions remain as impurities, which forms a battery against the metal or metal oxide that comes into contact with it, causing corrosion. There has been proposed a method for cleaning using a cleaning liquid containing the liquid (for example, see Patent Document 2).
However, with this method, the amount of residual iron ions may not be reduced below a certain level.
European Patent No. 440957 JP 2006-104314 A

The object of the present invention is to solve the above-mentioned problems of the prior art.
That is, an object of the present invention is to efficiently remove metal ions remaining in a conductive polymer synthesized by an oxidative polymerization method, thereby improving the durability of the conductive polymer including stability against light irradiation, and The purification method is provided.

The above-mentioned subject is achieved by the following present invention. That is, the present invention
<1> A π-conjugated polymer containing a polymer compound and having an iron ion content of 0.1 to 10 ppm by mass.

<2> The conductive polymer according to <1>, wherein the polymer compound is a conjugated polymer.

<3> The conductive polymer according to <2>, wherein the main skeleton structure of the polymer chain is polythiophene.

<4> The conductive polymer according to <2> or <3>, wherein the structure of the polymer chain is poly (3,4-ethylenedioxy-thiophene).

<5> A dispersion preparation step in which a conductive polymer is dispersed in a solvent to obtain a dispersion,
A dispersion contacting step of bringing the dispersion into contact with a carrier having a chelating agent fixed on the surface;
It is the purification method of the conductive polymer which has this.

<6> The method for purifying a conductive polymer according to <5>, wherein the carrier is silica gel.

<7> The method for purifying a conductive polymer according to <5> or <6>, wherein the chelating agent is a compound having at least one selected from an amino group, a carboxy group, a mercapto group, and a nitrogen-containing heterocyclic group. It is.

<8> The conductive polymer according to any one of <5> to <7>, wherein the dispersion liquid contains poly (3,4-ethylenedioxy-thiophene) and polystyrene-4-sulfonic acid. This is a purification method.

<9> The method for purifying a conductive polymer according to any one of <5> to <8>, wherein iron is removed from the conductive polymer.

  According to the present invention, a conductive polymer having improved durability including stability against light irradiation by efficiently removing metal ions remaining in a conductive polymer synthesized by an oxidative polymerization method, and The purification method can be provided.

Hereinafter, specific embodiments of the present invention will be described.
The conductive polymer of the present invention contains a polymer compound, and the iron ion content is in the range of 0.1 to 10 ppm by mass.
Here, the conductive polymer refers to a polymer exhibiting conductivity of 10 ⁻⁶ S · cm ⁻¹ or more, and any polymer can be used as long as it includes a polymer compound corresponding to this. it can. More preferably, it is a polymer having conductivity of 10 ⁻¹ S · cm ⁻¹ or more.

The polymer compound contained in the conductive polymer is preferably a non-conjugated polymer or a conjugated polymer in which aromatic carbocycles or aromatic heterocycles are connected by a single bond or a divalent or higher linking group.
Examples of the aromatic carbocyclic ring in the non-conjugated polymer or conjugated polymer include a benzene ring, which may further form a condensed ring and may have a substituent.
Examples of the aromatic heterocycle in the non-conjugated polymer or conjugated polymer include a pyridine ring, a birazine ring, a pyrimidine ring, a pyridazine ring, a triazine ring, an oxazole ring, a thiazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, Examples include triazole ring, tetrazole ring, furan ring, thiophene ring, pyrrole ring, indole ring, carbazole ring, benzimidazole ring, and imidazopyridine ring, which may further form a condensed ring and have a substituent. May be.

  The divalent or higher linking group in the non-conjugated polymer or conjugated polymer includes a linking group formed of a carbon atom, a silicon atom, a nitrogen atom, a boron atom, an oxygen atom, a sulfur atom, a metal, a metal ion, or the like. Is mentioned. Preferably, it is a group formed from a carbon atom, a nitrogen atom, a silicon atom, a boron atom, an oxygen atom, a sulfur atom and a combination thereof. The group formed by the combination includes a substituted or unsubstituted methylene group, carbonyl Group, imino group, sulfonyl group, sulfinyl group, ester group, amide group, silyl group and the like.

Specific examples of the polymer compound contained in the conductive polymer include substituted and unsubstituted polyaniline, polyparaphenylene, polyparaphenylene vinylene, polythiophene, polyfuran, polypyrrole, polyselenophene, polyisothianaphthene, Examples include polyphenylene sulfide, polyacetylene, polypyridyl vinylene, and polyazine. These may use only 1 type and may use it in combination of 2 or more type according to the objective.
Moreover, it can also use as a mixture of these high molecular compounds and another polymer, and the copolymer of the monomer which comprises these, and another monomer can also be used.

The polymer compound constituting the conductive polymer is more preferably a conjugated polymer. Examples of conjugated polymers include polyacetylene, polydiacetylene, poly (paraphenylene), polyfluorene, polyazulene, poly (paraphenylene sulfide), polypyrrole, polythiophene, polyisothianaphthene, polyaniline, poly (paraphenylene vinylene), poly (2,5-thienylene vinylene), double chain conjugated polymers (such as polyperinaphthalene), metal phthalocyanine polymers, other conjugated polymers (poly (paraxylylene), and poly [α- (5,5 '-Bithiophenediyl) benzylidene] and the like, and copolymers thereof.
Preferred are poly (paraphenylene), polypyrrole, polythiophene, polyaniline, poly (paraphenylene vinylene), poly (2,5-thienylene vinylene, and more preferred are poly (paraphenylene), polythiophene, and poly (paraphenylene). Vinylene) and the like.

  In general, the conjugated polymer means an organic polymer having a main chain composed of a π-conjugated system. These conjugated polymers (hereinafter sometimes referred to as “π-conjugated polymers”) are, for example, It can be produced by oxidative polymerization and electrolytic polymerization.

In the above electropolymerization method, an electrode material previously formed on a substrate is placed in a mixed solution of an electrolyte serving as a dopant and a monomer capable of forming a π-conjugated polymer, and a conductive polymer is formed on the electrode in the form of a film. To do. Therefore, it is difficult to manufacture in large quantities.
On the other hand, the oxidative polymerization method does not have such limitations, and a large amount of conductive polymer is polymerized in solution using a monomer that can theoretically form a π-conjugated polymer, an appropriate oxidant, and an oxidative polymerization catalyst. can do.

  However, it has been found that a conductive polymer containing a π-conjugated polymer has a problem that the resistance is increased by light irradiation, and the cause thereof is due to residual iron as an oxidizing agent used in the oxidative polymerization. The details of the mechanism are not clear, but it is thought that the iron remaining in the conductive polymer acts as a catalyst, takes electrons from the polymer by light irradiation, generates radicals, and these radicals break the polymer chain. .

For this reason, it is necessary to reduce the iron ion content in the synthesized conductive polymer to a certain level or less. For example, a conductive polymer containing a π-conjugated polymer is generally insoluble or difficult to dissolve in various solvents. A purification method cannot be adopted.
As a result of the study by the present inventors in view of the above, by a method in which a dispersion in which a conductive polymer is dispersed is brought into contact with a carrier on which a chelating agent is fixed as described later, the polymer in the polymer is remarkably compared with the conventional purification method. It was found that the iron ion concentration can be reduced.

  Specifically, the iron ion content with respect to the conductive polymer solid content in the conductive polymer of the present invention is in the range of 0.1 to 10 ppm by mass. When the iron ion content with respect to the conductive polymer solid content exceeds 10 ppm by mass, the resistance increases even with light irradiation with a light amount of 100,000 lux. A conductive polymer whose iron ion content with respect to the solid content of the conductive polymer is less than 0.1 ppm by mass exceeds the detection limit and is difficult to obtain in practice.

The iron ion content in the conductive polymer is preferably in the range of 0.2 to 10 ppm by mass, and more preferably in the range of 1 to 10 ppm by mass.
The iron ion content in the polymer can be determined by analysis such as atomic absorption. Details will be described later. The iron ion content in the present invention includes the content detected when the polymer compound and iron ions are present independently in the conductive polymer, and the polymer compound contains iron ions in the molecular structure. Any of the contents detected in the case of having

  The π-conjugated polymer may have a substituent in the main chain structure or as a part of the side chain, and the substituent may be an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 carbon atom). To 12, particularly preferably 1 to 8 carbon atoms, such as methyl group, ethyl group, iso-propyl group, tert-butyl group, n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, A cyclopentyl group, a cyclohexyl group, etc.), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably 2 to 8 carbon atoms, such as a vinyl group, an allyl group, 2-butenyl group, 3-pentenyl group, 2-hexenyl group, 3-hexenyl group, 4-hexenyl group, 2-octenyl group, etc.), alkynyl group (preferably Or a carbon number of 2 to 20, more preferably a carbon number of 2 to 12, particularly preferably a carbon number of 2 to 8, such as a propargyl group, a 3-pentynyl group, etc.), an aryl group (preferably a carbon number). 6 to 30, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyl group, p-methylphenyl group, naphthyl group, etc.), amino group (preferably carbon number) 0 to 20, more preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms, such as amino group, methylamino group, dimethylamino group, diethylamino group, dibenzylamino group, diphenylamino group, etc. ),

  Alkoxy groups (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methoxy group, ethoxy group, butoxy group, hexyloxy group, octyloxy group, etc. And an aryloxy group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as a phenyloxy group and a 2-naphthyloxy group). And an acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms, and examples thereof include an acetyl group, a benzoyl group, a formyl group, and a pivaloyl group. An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 12 carbon atoms). For example, a methoxycarbonyl group, an ethoxycarbonyl group, etc.), an aryloxycarbonyl group (preferably having a carbon number of 7-20, more preferably a carbon number of 7-16, particularly preferably a carbon number of 7-10, Examples thereof include a phenyloxycarbonyl group).

  An acyloxy group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as an acetoxy group and a benzoyloxy group), an acylamino group (preferably The number of carbon atoms is 2 to 20, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 10 carbon atoms. Examples thereof include acetylamino group and benzoylamino group), alkoxycarbonylamino group (preferably carbon number). 2 to 20, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as a methoxycarbonylamino group), an aryloxycarbonylamino group (preferably 7 to 20 carbon atoms, More preferably, it has 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms. And sulfonylamino groups (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms, such as methanesulfonylamino group and benzenesulfonylamino group). ), Sulfamoyl groups (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms, such as sulfamoyl group, methylsulfamoyl group, dimethyl group). Sulfamoyl group, phenylsulfamoyl group, etc.),

  A carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms, and examples thereof include a carbamoyl group, a methylcarbamoyl group, a diethylcarbamoyl group, and a phenylcarbamoyl group. ), An alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as a methylthio group and an ethylthio group), an arylthio group ( Preferably it has 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, and particularly preferably 6 to 12 carbon atoms, and examples thereof include a phenylthio group, and a sulfonyl group (preferably 1 to 20 carbon atoms, more. Preferably it is C1-C16, Most preferably, it is C1-C12, for example, a mesyl group, tosyl group etc. ), A sulfinyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include a methanesulfinyl group and a benzenesulfinyl group). A ureido group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include a ureido group, a methylureido group, and a phenylureido group). A phosphoric acid amide group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms, and examples thereof include a diethylphosphoric acid amide group and a phenylphosphoric acid amide group. ),

  Hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic ring Group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, and a sulfur atom. Specifically, for example, a pyrrolidine group, a piperidine group, Piperazine group, morpholine group, thiophene group, furan group, pyrrole group, imidazole group, pyrazole group, pyridine group, pyrazine group, pyridazine group, triazole group, triazine group, indole group, indazole group, purine group, thiazoline group, thiazole Group, thiadiazole group, oxazoline group, oxazole group, oxy Diazole, quinoline, isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzthiazole , Benzotriazole group, tetrazaindene group, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms such as trimethylsilyl group and triphenylsilyl group). Group, etc.).

  The above substituents may be further substituted. Moreover, when it has two or more substituents, those substituents may mutually be the same or different, and if possible, they may be connected to form a ring. Examples of the ring formed include a benzene ring, a thiophene ring, a dioxane ring, and a dithiane ring.

  The substituent is preferably an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkynyl group having 2 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkylthio having 1 to 12 carbon atoms. And more preferably an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, and an alkylthio group having 1 to 8 carbon atoms.

  Specific examples of the π-conjugated polymer are shown below, but the π-conjugated polymer in the present invention is not limited to these. In addition to these, compounds described in International Publication No. 98/01909 pamphlet and the like can be mentioned.

  Among these, as the π-conjugated polymer in the present invention, a polymer whose main skeleton structure is polythiophene is preferable, and specifically, a polymer having a repeating structure represented by the following general formula (I) is desirable.

In the above formula, R ¹¹ represents each of the above substituents, and m ¹¹ represents an integer of 0 to 2. When m ¹¹ represents 2, the plurality of R ¹¹ may be the same as or different from each other, and may be connected to each other to form a ring. The ^{n 11} represents an integer of 1 or more.
In addition, the main skeleton structure of the polymer means a repeating structure portion excluding the substituent R ¹¹ in the general formula (I).

In the polythiophene, the main skeleton structure represented by the general formula (I) is preferably an alkoxy group or an alkylthio group in which two R ¹¹ form a ring when m ¹¹ is 2, such as a dioxane ring or a dithiane ring. Is mentioned. When m ¹¹ is 1, R ¹¹ is preferably an alkyl group (an alkyl group having 2 to 8 carbon atoms). In addition, when R ¹¹ is poly (3-alkylthiophene) which is an alkyl group, the connection mode with adjacent thiophene rings is all stereoregular connected by 2-5 ′, 2-2 ′, Although there are sterically irregular ones containing 5-5 ′ linkages, sterically irregular ones are preferred.

The main skeleton structure represented by the general formula (I) is polythiophene, and poly (3,4-ethylenedioxy-thiophene) in which m ¹¹ is 2 and two R ¹¹ form a ring (explained compound (6 )) Is particularly preferable from the viewpoint of achieving both high transparency and conductivity.

The polythiophene represented by the general formula (I) and its derivatives are obtained by known methods such as J. Mater. Chem., 2005, 15, 2077-2088. And Advanced Materials 2000, 12 (7), page 481. Can be produced. In addition, commercially available products include Denatron P502 (manufactured by Nagase Chemi), 3,4-ethylenedioxythiophene (BAYTRON (registered trademark) MV2), 3,4-polyethylenedioxythiopene / polystyrenesulfonate (BAYTRON (registered trademark) P), BAYTRON (registered trademark) C ), BAYTRON (registered trademark) FE, BAYTRON (registered trademark) M V2, BAYTRON (registered trademark) P, BAYTRON (registered trademark) P AG, BAYTRON (registered trademark) P HC V4, BAYTRON (registered trademark) P HS, BAYTRON (Registered Trademark) PH, BAYTRON (Registered Trademark) PH 500, BAYTRON (Registered Trademark) PH 510 (above, Stark Co., Ltd.) and the like can be obtained.
As polyaniline and derivatives thereof, polyaniline (manufactured by Aldrich), polyaniline (eleraldine salt) (manufactured by Aldrich) and the like can be obtained.
Polypyrrole (manufactured by Aldrich) and the like can be obtained as polypyrrole and derivatives thereof.

  The weight average molecular weight of the π-conjugated polymer is preferably in the range of 1,000 to 1,000,000, more preferably in the range of 10,000 to 500,000, and still more preferably in the range of 10,000 to 100,000.

  When a π-conjugated polymer is used as the conductive polymer, it is preferable that the π-conjugated polymer contains at least one dopant. The dopant contained in the π-conjugated polymer is an electron accepting (acceptor) dopant, an electron donating property. In the present invention, a dopant is an additive having an effect of improving its conductivity by being added to a conductive polymer. Means a thing.

Examples of the electron accepting (acceptor) dopant include halogen (Cl ₂ , Br ₂ , I ₂ , ICl, ICl ₃ , IBr, IF), Lewis acid (PF ₅ , AsF ₅ , SbF ₅ , BF ₃ , BCl ₃ , BBr ₃ , SO ₃ ), protonic acid (HF, HCl, HNO ₃ , H ₂ SO ₄ , HClO ₄ , FSO ₃ H, ClSO ₃ H, CF ₃ SO ₃ H, various organic acids, amino acids, etc.), transition metal Compounds (FeCl ₃ , FeOCl, TiCl ₄ , ZrCl ₄ , HfCl ₄ , NbF ₅ , NbCl ₅ , TaCl ₅ , MoF ₅ , MoCl ₅ , WF ₆ , WCl ₆ , UF ₆ , LnCl ₃ (Ln = La, Ce, , Nd, lanthanides such as Sm), an electrolyte anion ^{(Cl -, Br -, I} -, ClO 4 -, PF 6 -, AsF ^{_{-, SbF 6 -, BF 4}} -, various sulfonic acid anion), and other ^{_{O 2, XeOF 4, (NO}} 2 +) (SbF 6 -), (NO 2 +) (SbCl 6 -), (NO 2 +) (BF ₄ ⁻ ), FSO ₂ OOSO ₂ F, AgClO ₄ , H ₂ IrCl ₆ , La (NO ₃ ) ₃ .6H ₂ O, and the like.

Examples of electron donating (donor) dopants include alkali metals (Li, Na, K, Rb, Cs), alkaline earth metals (Ca, Sr, Ba), lanthanoids (Eu, etc.), and others (R ₄ N ⁺ , R ₄ P ⁺ , R ₄ As ⁺ , R ₃ S ⁺ , acetylcholine) and the like.

Examples of the combination of the dopant and the π-conjugated polymer include:
(A) such as polyacetylene and _{I 2, AsF 5, FeCl 3} ;
(B) poly (p-phenylene) and AsF ₅ , K, AsF ₆ ^{— and the} like;
(C) polypyrrole and ClO ₄ ^{— and the} like;
(D) polythiophenes and ClO ₄ ⁻ , sulfonic acid compounds, particularly polystyrene sulfonic acid, nitrosonium salts, aminium salts, quinones, etc .;
(E) polyisothianaphthene and I ₂ etc .;
(F) poly (p-phenylene sulfide) and AsF ₅ ;
(G) poly (p-phenylene oxide) and AsF ₅ ;
(H) polyaniline and HCl;
(I) poly (p-phenylene vinylene) and H ₂ SO ₄ etc .;
(J) polythiophenylene vinylene and I ₂ etc .;
(K) nickel phthalocyanine and I ₂ etc .;
Etc.

  Among these combinations, the combination of the above (D) is preferable, and more preferable is a combination of polythiophenes (polythiophene and derivatives thereof) and a sulfonic acid compound from the viewpoint of high stability of the doped state, Preferably, it is a combination of polythiophenes and polystyrene sulfonic acid from the viewpoint that the aqueous dispersion can be adjusted and the conductive thin film can be easily adjusted by coating.

  The ratio of the π-conjugated polymer and the dopant may be any, but from the viewpoint of achieving both the stability of the doped state and the conductivity, preferably the π-conjugated polymer: dopant = 1.0 in terms of mass ratio. : 0.0000001 to 1.0: 10, more preferably 1.0: 0.00001 to 1.0: 1.0, and still more preferably 1.0: 0.0001 to 1.0. : It is the range of 0.5.

  The conductive polymer may be an ion conductive polymer in which a polymer chain is doped with an electrolyte. Examples of the polymer chain include polyether (polyethylene oxide, polypropylene oxide, etc.), polyester (polyethylene succinate, Poly-β-propiolactone, etc.), polyamine (polyethyleneimine, etc.), polysulfide (polyalkylene sulfide, etc.) and the like, and doped electrolytes include various alkali metal salts.

Examples of the alkali metal ions constituting the alkali metal salt include Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , and the anions forming the counter salt include F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , and the like. NO ₃ ⁻ , SCN ⁻ , ClO ₄ ⁻ , CF ₃ SO ₃ ⁻ , BF ₄ ⁻ , AsF ₆ ⁻ , BPh ₄ ^{− and the} like can be mentioned.

Examples of combinations of polymer chains and alkali metal salts include polyethylene oxide and LiCF ₃ SO ₃ , LiClO ₄ , polyethylene succinate and LiClO ₄ , LiBF ₄ , poly-β-propiolactone and LiClO ₄ , polyethyleneimine, and the like Examples include NaCF ₃ SO ₃ and LiBF ₄ , polyalkylene sulfide and AgNO ₃ .

In the present invention, by the doping, the conductivity is 0.01 Scm ^-1 or more, more preferably 0.1Scm ^-1 or more conductive polymer is obtained.
Further, the surface resistance value is desirably in the range of 0.01 to 100,000,000 Ω / □, and more preferably in the range of 0.1 to 100,000 Ω / □.

In addition, since the conductive polymer of this invention has little iron ion content, it is stable with respect to light irradiation. Specifically, for example, the increase in the surface resistance value after 100 hours of light irradiation with a xenon lamp (light intensity: 180 W / m ² ) is preferably within 300%, and more preferably within 200%. is there.

Next, a method for synthesizing the conductive polymer before purification in the present invention will be described.
In the present invention, the conductive polymer before purification is synthesized by an oxidative polymerization reaction using an aromatic sulfonic acid metal salt or the like as an oxidizing agent from a monomer of the π-conjugated polymer, for example, when the polymer compound is a π-conjugated polymer. Is done. Examples of the monomer of the π-conjugated polymer include pyrrole, thiophene, aniline, phenylene, acetylene, furan, phenylene vinylene, azulene, and derivatives thereof.

  Examples of the aromatic sulfonic acid metal salt that is an oxidizing agent include ferric o-toluenesulfonate, ferric m-toluenesulfonate, ferric p-toluenesulfonate, cupric o-toluenesulfonate, m -Cupric toluene sulfonate, cupric p-toluene sulfonate, cobalt o-toluene sulfonate, cobalt m-toluene sulfonate, cobalt p-toluene sulfonate, manganese o-toluene sulfonate, m-toluene sulfonic acid Examples thereof include manganese, manganese p-toluenesulfonate, ferric o-ethylbenzenesulfonate, ferric m-ethylbenzenesulfonate, ferric p-ethylbenzenesulfonate, ferric naphthalenesulfonate, and derivatives thereof.

As the aromatic sulfonic acid metal salt exemplified above, ferric p-toluenesulfonate and cupric p-toluenesulfonate are preferable because of easy control of reaction and industrial availability.
In addition to the above, it is desirable to use iron chloride, copper chloride or the like as the oxidation polymerization catalyst.

  In the present invention, the oxidative polymerization reaction between the monomer of the π-conjugated polymer and the aromatic sulfonic acid metal salt can be performed by a conventionally known method. Specifically, for example, in an organic solvent such as ethanol, an aromatic sulfonic acid metal salt of 1 to 4 times (molar ratio) is added to the monomer of the π-conjugated polymer as a starting material, and several tens of A π-conjugated polymer can be obtained by reacting for minutes to several hours. The obtained π-conjugated polymer is subjected to a purification method to be described later after washing with a solvent such as pure water or ethanol.

  In addition, when using the said dopant, this dopant may be added to the solution containing the said monomer, an oxidizing agent, and / or an oxidation polymerization catalyst before superposition | polymerization of (pi) conjugated polymer, and (pi) conjugate after superposition | polymerization of (pi) conjugated polymer. It may be added to the polymer.

Next, the method for purifying the conductive polymer of the present invention will be described.
The method for purifying a conductive polymer of the present invention comprises a step of preparing a dispersion in which at least a conductive polymer is dispersed in a solvent, and a dispersion in which the dispersion is brought into contact with a carrier having a chelating agent fixed on the surface. And a contact step.
In addition, the refinement | purification method of the conductive polymer of this invention is applicable not only to what contains a dopant etc. but to the conductive polymer which consists of polymers alone, such as (pi) conjugated polymer which does not contain them.

  As described above, for example, a conductive polymer containing a π-conjugated polymer is hardly soluble in various solvents. Therefore, a reprecipitation purification method or the like generally used as a polymer purification method is not effective. On the other hand, when the conductive polymer is formed on a substrate or the like, a relatively dense film is formed, so that impurities inside the film cannot be removed by cleaning.

For this reason, in the present invention, the conductive polymer before film formation is purified, and in particular, in order to efficiently remove metal ions in the polymer, as a result of various studies, a chelating agent was fixed on the surface. It has been found that the amount of metal ions contained can be greatly reduced by contacting a carrier with a dispersion in which a conductive polymer is dispersed with a predetermined particle size. Further, in this case, by fixing the chelating agent to the surface of the carrier, mixing of the chelating agent into the conductive polymer at the time of contact can be prevented.
And it turned out that the refinement | purification method of the electroconductive polymer of this invention is effective in reducing especially the amount of iron ions contained in a polymer.

Hereinafter, the purification method of the conductive polymer of the present invention will be described for each step.
-Dispersion preparation process-
In this step, first, a dispersion of a conductive polymer used for purification is prepared.
The solvent used in the dispersion is not particularly limited because the conductive polymer containing the π-conjugated polymer is insoluble in any solvent as described above. It is desirable to select a solvent that is excellent in dispersion characteristics and is not damaged when contacted with a carrier having a chelating agent immobilized on the surface described later.

  From the above viewpoint, water, alcohol, and the like can be selected as the solvent, and these can be used alone or in combination. Among the solvents, it is particularly preferable to use water.

Next, the π-conjugated polymer is dispersed in the solvent. For the dispersion, a jaw crusher method, an ultracentrifugation method, a cutting mill method, an automatic mortar method, a disk mill method, a ball mill method, an ultrasonic dispersion method, or the like is appropriately used. .
In this case, the content of the conductive polymer in the dispersion is preferably in the range of 0.01 to 50% by mass, and more preferably in the range of 0.1 to 10% by mass.

The dispersed particle diameter of the π-conjugated polymer after dispersion is preferably in the range of 0.0001 to 1000 μm in terms of number average particle diameter, and more preferably in the range of 0.001 to 100 μm.
In addition, the said number average particle diameter can be measured using the particle size distribution measuring device Microtrac (Microtrac) particle size distribution measuring apparatus MT3000II series (made by Nikkiso Co., Ltd.).

  In preparation of the dispersion, a compound having a sulfonate ion is added to the dispersion in order to dope with the dispersion, for example, as a dopant in a π-conjugated polymer, or to prevent dedoping of an already doped dopant. It is desirable to do.

  Examples of the compound having a sulfonate ion include p-toluenesulfonic acid monohydrate, tetraethylammonium-p-toluenesulfonic acid, mono-p-toluenesulfonic acid urea, sodium p-toluenesulfonate, 2-amino-5-methylbenzene-1-sulfonic acid, 1-cyclohexyl-3- (2-morpholinoethyl) carbodiimide meth-p-toluenesulfonic acid, N-cyclohexyl-N ′-(2-morpholinoethyl) carbodiimide meth -P-toluenesulfonic acid salt, p-toluenesulfonyl hydrazide, naphthalenesulfonic acid and its derivatives. Examples of the polymer compound include polystyrene-4-sulfonic acid.

Among these, it is desirable to use polystyrene-4-sulfonic acid from the viewpoint that the aqueous dispersion can be adjusted and the conductive thin film can be easily adjusted by coating.
Further, the ratio of the conjugated polymer such as a π-conjugated polymer and the dopant may be any, but from the viewpoint of achieving both the stability of the doped state and the conductivity, the conductive polymer is preferably used in a mass ratio. : Dopant = 1.0: 0.0000001 to 1.0: 10, preferably 1.0: 0.00001 to 1.0: 1.0, and more preferably 1.0: 0. The range is 0001 to 1.0: 0.5.

  The compound having a sulfonate ion can also be used as a pH adjuster for the dispersion, but as other pH adjuster, sulfuric acid, nitric acid, aqueous ammonia, or the like can be used in addition to the above compound. it can.

-Dispersion contact process-
In this step, impurities such as metal ions in the conductive polymer are removed by bringing the prepared dispersion into contact with a carrier having a chelating agent immobilized on the surface. First, the support | carrier which fixed the chelating agent to the surface used for this process is demonstrated.

The chelating agent used in the present invention is not particularly limited as long as it has the ability to chelate metal ions, but one having a specific functional group is used.
The functional group contained in the chelating agent is preferably an amino group, a carboxy group, a mercapto group, a hydroxy group, a sulfonic acid group, a thiourea group, an aromatic group, or a nitrogen-containing heterocycle. More preferred are amino group, carboxy group, mercapto group, hydroxy group, nitrogen-containing heterocyclic group and thiourea group. Particularly preferred are amino group, carboxy group, nitrogen-containing heterocyclic group and mercapto group. A plurality of these functional groups may be present, or a plurality of functional groups may be combined. In particular, a structure having two or more amino groups is preferable.

  Specific examples of the functional group include propylamino group, butylamino group, N-aminoethylaminopropyl group, N-aminoethyl-N-aminoethyl-N-aminopropyl group, diethylaminopropyl group, triaminetetraacetic acid group, Mercaptopropyl group, mercaptobutyl group, N-methyl-N-propylthiourea group, N-ethyl-N-butylthiourea group, sulfoxypropyl group, sulfoxybutyl group, 4-sulfophenyl-2-ethyl group, 4- Examples include a sulfophenyl-3-propyl group, a 2-pyridylpropyl group, and a 4-pyridylbutyl group.

Further, these functional groups may further have a substituent, and examples of the substituent include the following substituent group V.
(Substituent group V)
Halogen atom (eg, chlorine, bromine, iodine, fluorine); mercapto group; cyano group; carboxyl group; phosphate group; sulfo group; hydroxy group; carbon number 1-10, preferably carbon number 2-8, more preferably carbon A carbamoyl group having 2 to 5 carbon atoms (for example, methylcarbamoyl group, ethylcarbamoyl group, morpholinocarbamoyl group); a sulfamoyl group having 0 to 10 carbon atoms, preferably 2 to 8 carbon atoms, more preferably 2 to 5 carbon atoms (for example, methyl). Sulfamoyl group, ethylsulfamoyl group, piperidinosulfamoyl group); nitro group; C1-C20, preferably C1-C10, more preferably C1-C8 alkoxy group (for example, methoxy) Group, ethoxy group, 2-methoxyethoxy group, 2-phenylethoxy group); carbon number 6-20, preferably carbon number 6-1 More preferably an aryloxy group having 6 to 10 carbon atoms (for example, phenoxy group, p-methylphenoxy group, p-chlorophenoxy group, naphthoxy group); 1 to 20 carbon atoms, preferably 2 to 12 carbon atoms, more preferably Is an acyl group having 2 to 8 carbon atoms (for example, acetyl group, benzoyl group, trichloroacetyl group); an acyloxy group having 1 to 20 carbon atoms, preferably 2 to 12 carbon atoms, and more preferably 2 to 8 carbon atoms (for example, acetyl group). An oxy group, a benzoyloxy group); an acylamino group having 1 to 20 carbon atoms, preferably 2 to 12 carbon atoms, and more preferably 2 to 8 carbon atoms (for example, an acetylamino group);

  A sulfonyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms (for example, methanesulfonyl group, ethanesulfonyl group, benzenesulfonyl group); 1 to 20 carbon atoms, preferably carbon number 1 to 10, more preferably a sulfinyl group having 1 to 8 carbon atoms (for example, methanesulfinyl group, ethanesulfinyl group, benzenesulfinyl group); 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 carbon atom To -8 sulfonylamino groups (for example, methanesulfonylamino group, ethanesulfonylamino group, benzenesulfonylamino group); 0 to 20 carbon atoms, preferably 0 to 12 carbon atoms, more preferably 0 to 8 carbon atoms. Substituted amino groups (for example, unsubstituted amino group, methylamino group, dimethylamino group, benzylamino group) Group, anilino group, diphenylamino group); an ammonium group having 0 to 15 carbon atoms, preferably 3 to 10 carbon atoms, more preferably 3 to 6 carbon atoms (for example, trimethylammonium group or triethylammonium group); 15, preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon hydrazino groups (for example, trimethylhydrazino group); 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 1 carbon atoms. 6 ureido groups (for example, ureido group, N, N-dimethylureido group); imide groups having 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms (for example, succinimide groups);

  An alkylthio group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms (for example, methylthio group, ethylthio group, propylthio group); 6 to 80 carbon atoms, preferably 6 to 40 carbon atoms More preferably, the arylthio group having 6 to 30 carbon atoms (for example, phenylthio group, p-methylphenylthio group, p-chlorophenylthio group, 2-pyridylthio group, 1-naphthylthio group, 2-naphthylthio group, 4-propylcyclohexyl group) 4′-biphenylthio group, 4-butylcyclohexyl-4′-biphenylthio group, 4-pentylcyclohexyl-4′-biphenylthio group, 4-propylphenyl-2-ethynyl-4′-biphenylthio group); carbon number Heteroarylthio having 1 to 80, preferably 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms (For example, 2-pyridylthio group, 3-pyridylthio group, 4-pyridylthio group, 2-quinolylthio group, 2-furylthio group, 2-pyrrolylthio group); 2-20 carbon atoms, preferably 2-12 carbon atoms, more preferably C2-C8 alkoxycarbonyl group (for example, methoxycarbonyl group, ethoxycarbonyl group, 2-benzyloxycarbonyl group); C6-C20, preferably C6-C12, more preferably C6-C10 An aryloxycarbonyl group (eg, phenoxycarbonyl group);

  An unsubstituted alkyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, or a butyl group); Is a substituted alkyl group having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms (for example, hydroxymethyl group, trifluoromethyl group, benzyl group, carboxyethyl group, ethoxycarbonylmethyl group, acetylaminomethyl group, An unsaturated hydrocarbon group having 2 to 18 carbon atoms, preferably 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms (for example, vinyl group, ethynyl group 1-cyclohexenyl group, benzylidine group, benzylidene group) is also substituted alkyl. To be included in the group}; substituted or non-substituted having 6 to 20 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms A substituted aryl group (for example, phenyl group, naphthyl group, p-carboxyphenyl group, p-nitrophenyl group, 3,5-dichlorophenyl group, p-cyanophenyl group, m-fluorophenyl group, p-tolyl group, 4- Propylcyclohexyl-4′-biphenyl, 4-butylcyclohexyl-4′-biphenyl, 4-pentylcyclohexyl-4′-biphenyl, 4-propylphenyl-2-ethynyl-4′-biphenyl); 1 to 20 carbon atoms, preferably Is a substituted or unsubstituted heterocyclic group having 2 to 10 carbon atoms, more preferably 4 to 6 carbon atoms (for example, pyridyl group, 5-methylpyridyl group, thienyl group, furyl group, morpholino group, tetrahydrofurfuryl group); Is mentioned.

  Examples of the chelating agent having the functional group include aminopolycarboxylic acid chelating agents, aromatic and aliphatic carboxylic acid chelating agents, amino acid chelating agents, ether polycarboxylic acid chelating agents, hydroxycarboxylic acid chelating agents, dithiocarbamine Examples thereof include S-containing chelating agents such as acid type, dithioic acid type, thiol type, and thiourea type, phosphoric acid chelating agents, polymer electrolyte (including oligomer electrolyte) chelating agents, and dimethylglyoxime (DG). These chelating agents may be in the free acid form or in the form of a salt such as sodium salt, potassium salt, or ammonium salt. Furthermore, they may be in the form of their ester derivatives which are hydrolysable.

Specific examples of the aminopolycarboxylic acid chelating agent include a) a compound represented by the chemical formula R ²² N (Y ¹ ) ₂ , b) a compound represented by the chemical formula N (Y ¹ ) ₃ , c) a chemical formula R ²² − A compound represented by N (Y ¹ ) —CH ₂ CH ₂ —N (Y ¹ ) —R ²² ; d) represented by the chemical formula R ²² —N (Y ¹ ) —CH ₂ CH ₂ —N (Y ¹ ) _2. Compounds, e) chemical formulas (Y ¹ ) ₂ N—R ²³ —N (Y ¹ ) ₂ , and f) compounds similar to the compound of e), including compounds containing 4 or more of Y ¹ It is done.

In the above formulas, Y ¹ represents —CH ₂ COOH or —CH ₂ CH ₂ COOH, and R ²² represents a group constituting a known chelating agent such as a hydrogen atom, an alkyl group, a hydroxyl group, or a hydroxyalkyl group. R ²³ represents a group constituting this kind of known chelating agent such as an alkylene group or a cycloalkylene group.

  Specific examples of the aminopolycarboxylic acid chelating agent include ethylenediaminetetraacetic acid (EDTA), cyclohexanediaminetetraacetic acid (CDTA), nitrilotriacetic acid (NTA), iminodiacetic acid (IDA), and N- (2-hydroxyethyl) iminodi. Examples include acetic acid (HIMDA), diethylenetriaminepentaacetic acid (DTPA), N- (2-hydroxyethyl) ethylenediaminetriacetic acid (EDTA-OH) and glycol etherdiaminetetraacetic acid (GEDTA), and salts thereof.

Specific examples of the aromatic or aliphatic carboxylic acid chelating agent include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, itaconic acid, aconitic acid, pyruvic acid, salicylic acid, acetylsalicylic acid, hydroxybenzoic acid. Acid, aminobenzoic acid (including anthranilic acid), phthalic acid, trimellitic acid and gallic acid, and their salts, methyl esters and ethyl esters.
Specific examples of the amino acid chelating agent include glycine, serine, alanine, lysine, cystine, cysteine, ethionine, tyrosine, methionine, and salts and derivatives thereof.

Furthermore, specific examples of the ether polycarboxylic acid chelating agent include diglycolic acid and its similar compounds and salts thereof (for example, sodium salts).
Examples of the hydroxycarboxylic acid-based chelating agent include malic acid, citric acid, glycolic acid, gluconic acid, heptonic acid, tartaric acid, lactic acid, and salts thereof.
Specific examples of the phosphate chelating agent include orthophosphoric acid, pyrophosphoric acid, triphosphoric acid, and polyphosphoric acid. Examples of the polymer electrolyte (including oligomer electrolyte) chelating agent include acrylic acid polymer, maleic anhydride polymer, α-hydroxyacrylic acid polymer, itaconic acid polymer, and structures of these polymers. Examples thereof include a copolymer composed of two or more monomers and an epoxy succinic acid polymer.

Specific examples of the S-containing chelating agent include 2-mercaptobenzothiazole or an alkali metal salt thereof, thionalide, dithizone, p-dimethylaminobenzylidene rhodanine, pipecoline pipecolyl dithiocarbamate, di-β-naphthylthiocarbazone. , Bismuthiol II, 2-mercaptoimidazoline, thiophenol and the like.
Furthermore, in the present invention, thiourea, ascorbic acid, thioglycolic acid, phytic acid, glyoxylic acid, glyoxalic acid, and salts thereof can also be suitably used as chelating agents.

  Among these specific chelating agents, preferred chelating agents include chelating agents having amino groups, carboxy groups, nitrogen-containing heterocyclic groups, mercapto groups, and thiourea groups. In particular, as a chelating agent for collecting iron ions, a chelating agent having an amino group, a carboxy group, a nitrogen-containing heterocyclic group, or a mercapto group is preferably used.

The carrier in the present invention is formed by immobilizing the chelating agent on the surface.
The carrier used in the present invention may be spherical, rod-shaped, tube-shaped, or the like, but is preferably spherical. As a material, inorganic carriers such as porous glass, glass beads, alumina, titania, zirconia, and the like can be used as appropriate in addition to silica gel. It is also possible to use carrier materials based on organic polymer gels such as polystyrene gel and polyvinyl alcohol gel and polysaccharides such as agarose and cellulose.
Among these, silica gel and polystyrene gel are preferable, and silica gel is particularly preferably used in consideration of the surface area of the support material and the reactivity between the silylating agent described later and the hydroxyl group on the support surface.

  When the carrier is spherical, the average particle size of the carrier is preferably in the range of 1 to 1000 μm, and more preferably in the range of 5 to 100 μm.

  The method for immobilizing the chelating agent on the surface of the carrier is not particularly limited, but it is preferable to bind the chelating agent and the carrier by a covalent bond. Specifically, (1) a method of forming a covalent bond with a silica gel surface using a silane coupling reaction, a method of forming a covalent bond with a titanium oxide surface using a titanium coupling reaction, or (2) A method of reacting a chelating agent with the reactive silane coupling agent after modifying the carrier in advance by reactive silane coupling is preferred. Preferably, the surface of the silica gel is utilized by utilizing the silane coupling reaction of (1). And form a covalent bond.

Examples of the coupling agent used in the method (1) include a silane coupling agent and a titanium coupling agent. A silane coupling agent is more preferably used. For example, a silane compound having a structure represented by the following general formula (1) is used.
Formula _(1): R m SiY _n
(In the above formula, R represents an alkoxy group, an acetoxy group, an aryloxy group, a halogen atom, m represents an integer of 1 to 3, Y represents an alkyl group having a functional group capable of chelating a metal ion, and aryl. And n is an integer of 1 to 3.)

Specifically, those having an alkoxysilyl group, a chlorosilyl group, and an alkoxychlorosilyl group are preferable, and examples thereof include those having trimethoxysilane, triethoxysilane, triacetoxysilane, trichlorosilane, and the like.
Preferably, it has an alkoxysilyl group and a chlorosilyl group, and more preferably has an alkoxysilyl group.

That is, for example, when alkoxysilane is used as a coupling agent, the bonded state after the reaction is (chelating agent) -A- (O) _n- (carrier) (where A is a spacer group, n: 0 or 1) In addition, as the spacer group (A), an alkylsilyl group is particularly advantageously used.
In the present invention, from the viewpoint of high metal adsorption efficiency, the length of the alkyl group in the alkylsilyl group is preferably 1 to 30 carbon atoms, and more preferably 1 to 20 carbon atoms.

  Specific examples of the compound represented by the general formula (1) include 4-aminobutyltrimethoxysilane, 5-aminopentyltrimethoxysilane, 4-carboxybutyltrimethoxysilane, 5-carboxy-aminopentyltrimethoxysilane, 4-mercaptobutyltrimethoxysilane, 5-mercaptopentyltrimethoxysilane, 4-hydroxybutyltrimethoxysilane, 5-hydroxypentyltrimethoxysilane, 4-sulfobutyltrimethoxysilane, 5-sulfopentyltrimethoxysilane, 4- Phenylbutyltrimethoxysilane, 5-phenylpentyltrimethoxysilane, 4-2-pyridylbutyltrimethoxysilane, 5-2-pyridylpentyltrimethoxysilane, 2-2-pyridylethylthiopropyltrimethoxysilane, -4-pyridylethylthiopropyltrimethoxysilane, bis-3-triethoxysilylpropylthiourea, N-3-trimethoxysilylpropylpyrrole, 2-trimethoxysilylethylpyridine, p-aminophenyltrimethoxysilane, 3-aminopropyl And tris (methoxyethoxyethoxy) silane.

  Among these, 4-aminobutyltrimethoxysilane, 5-aminopentyltrimethoxysilane, 4-mercaptobutyltrimethoxysilane, 5-mercaptopentyltrimethoxysilane, 4-2-pyridylbutyltrimethoxysilane, 5-2 -Pyridylpentyltrimethoxysilane, -2-pyridylethylthiopropyltrimethoxysilane, 2-4-pyridylethylthiopropyltrimethoxysilane, bis-3-triethoxysilylpropylthiourea, N-3-trimethoxysilylpropylpyrrole, 2-Trimethoxysilylethylpyridine, p-aminophenyltrimethoxysilane, 3-aminopropyltris (methoxyethoxyethoxy) silane, and the like can be suitably used.

  Next, the reactive silane coupling agent used in the method (2) will be described. As the reactive site, an epoxy group, an isocyanate group, an amino group, a mercapto group, a hydroxy group, a halogen atom, an acid anhydride, or the like is preferably used. Specifically, 2-3,4-epoxycyclohexylethyltriethoxysilane, 2-3,4-epoxycyclohexylethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane 5,6-epoxyhexyltriethoxysilane, 3-triethoxysilylpropylsuccinic anhydride, 3-iodopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, chloromethylphenylethylmethyldimethoxysilane, 3-isocyanate Examples thereof include propyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-thioisocyanatepropyltriethoxysilane, and 3-thioisocyanatepropyltrimethoxysilane.

  Among these, 2-3,4-epoxycyclohexylethyltriethoxysilane, 2-3,4-epoxycyclohexylethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane , 3-triethoxysilylpropylsuccinic anhydride, 3-isocyanatopropyltriethoxysilane, etc. can be suitably used.

As described above, the chelating agent is immobilized on the surface of the carrier, but the amount of the chelating agent to be immobilized is preferably in the range of 0.01 to 1000 mmol% in the carrier after immobilization, and 0.1 to 100 mmol. % Is more preferable.
When the amount of immobilization is in the above range, not only can metal ions in the conductive polymer be efficiently collected, but also contamination of the desorbed chelating agent can be suppressed.

  Examples of suitable carriers used in the present invention include SiliaBond Diamine, SiliaBond Diamine, SiliaBond TAAcOH, SiliaBond TBD, and SiliaBond Triamine (all manufactured by SiliCycle).

Next, the carrier having the chelating agent immobilized on the surface prepared above is brought into contact with the dispersion containing the π-conjugated polymer.
The method for bringing the dispersion into contact with the carrier is not particularly limited, and examples thereof include a method in which the carrier is introduced into the dispersion, and a method in which the carrier is fixed as a column and the dispersion is fluidized.

In this case, the mass ratio between the dispersion and the carrier (in the case of a dispersion / carrier, a column, etc., the mass ratio in the state where the whole of the packed carrier is filled with the dispersion) is 1/10 to 10,000 / A range of 1 is desirable, and a range of 1/1 to 1,000 / 1 is more preferred. More specifically, it is desirable that the ratio (chelate / repeating unit) between the molar concentration of the chelate moiety in the carrier and the molar concentration of the repeating unit in the π-conjugated polymer be in the range of 1 / 0.001 to 1 / 0.5. The range of 1 / 0.01 to 1 / 0.2 is more preferable.
By setting the mass ratio within the above range, the metal ion content can be efficiently reduced to a desired value in a short time.

In addition, the temperature of the dispersion is preferably in the range of 0 to 100 ° C., more preferably in the range of 20 to 80 ° C., in order to promote the chelation reaction.
Furthermore, the contact time between the dispersion and the carrier (in the case of a column or the like, the time from when the liquid flows into the carrier until it flows out) is preferably in the range of 1 second to 1 week, and is preferably 1 minute to 24. It is more preferable to set the time range.

  The conductive polymer of the present invention is preferably formed into a film. In addition, film formation by coating is also preferable from the viewpoint of simplicity of device fabrication that allows a large area to be coated at once. Application may be performed, for example, using an aqueous dispersion of a conductive polymer on a substrate, or using an organic solvent dispersion.

  Although there is no restriction | limiting in particular in the film thickness of the formed conductive polymer layer, It is preferable that it is the range of 1 nm-2 micrometers, and it is more preferable that it is the range of 10 nm-1 micrometer. If the film thickness of the conductive polymer layer is within this range, sufficient conductivity and transparency can be achieved. If it is 1 nm or less, there is a concern that the conductivity is insufficient, such being undesirable.

  When the conductive polymer layer (conductive film) is formed on a resin base material, the resin base material used is a dimensionally stable plate-like material and has the necessary flexibility, strength and durability. Any one can be used as long as it satisfies the characteristics. Moreover, when using the obtained conductive polymer layer for an image display element, a solar cell, etc., since high transparency is requested | required, it is preferable to use the transparent base material of surface smoothness.

  Examples of the base material that satisfies the required light transmittance such as flexibility, strength, and durability, and has excellent transmittance in the visible light wavelength range include, for example, cellulose diacetate, cellulose triacetate, cellulose propionate, and cellulose butyrate. And a film using a resin such as cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, and polyarylate. Among these, when applied to a liquid crystal display panel or the like, polycarbonate, polyarylate and the like are preferable from the viewpoint of optical characteristics and thermal characteristics. The thickness of the resin substrate can be appropriately selected depending on the purpose, but is generally in the range of 10 to 200 μm.

  The formed conductive film can be suitably used for a flexible electroluminescence device (OLED), a touch screen, an organic TFT, and the like. Further, by selecting a material to make this conductive film a transparent conductive film, it can be suitably used for an image display element such as a flexible liquid crystal display, a solar cell, and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, this invention is not limited to them.

<Measurement methods for various physical properties>
Various physical property values shown in the following examples and comparative examples are obtained by the following measurement methods.
(Iron ion content)
Using an atomic absorption spectrophotometer AA series apparatus (manufactured by Shimazu), the iron ion content in the conductive polymer was measured by the atomic absorption method. The measurement conditions were a double beam method.

(Surface resistance value)
The surface resistance value of the synthesized conductive polymer was measured at 23 ° C. using a resistance measuring instrument (EP MCP-T360 type, manufactured by Loresta Instruments Co., Ltd.) with respect to the formed sample.

(Transmittance)
The transmittance of the obtained conductive polymer film was determined as the transmittance in the visible light region with a UV / vis spectrum meter (UV3600, manufactured by Shimadzu Corporation) using a film having a thickness of 188 μm.

<Example 1>
(Synthesis of conductive polymer)
7.1 g of 3,4-ethylenedioxy-thiophene (manufactured by Aldrich), 100 ml of polystyrene-4-sulfonic acid aqueous solution (manufactured by Aldrich, solid content: 18% by mass), and 100 ml of water were mixed and stirred at room temperature. While adding 1.5 g of ammonium persulfate and 0.4 g of ferric sulfate, the mixture was stirred at room temperature for 3 hours. Subsequently, after adding 200 ml of water, it centrifuged and took out solid content.

(Purification of conductive polymer)
To the solid content, 200 ml of water was added and centrifuged again to take out the solid content. This operation was repeated three times, and then 200 ml of water was added to obtain a conductive polymer aqueous dispersion (dispersion preparation step). The dispersed particle diameter of the polymer particles in the dispersion at this time was 0.3 μm.

Next, SiliaBond Diamine (SiliCycle, average particle size: 50 μm, immobilization amount: 1.4 mmol%, spacer part carbon number, a carrier obtained by immobilizing ethylenediamine on the silica gel surface with a silane coupling agent in the aqueous dispersion. : 3) 5.0 g was added and the mixture was stirred at room temperature for 3 hours.
Then, the said support | carrier was isolate | separated by filtering with a filter cloth and the mixed water dispersion liquid of poly (3,4-ethylenedioxy-thiophene) and polystyrene-4-sulfonic acid was obtained.

(Evaluation)
The same amount of ethylene glycol as the polymer is added to the aqueous dispersion containing poly (3,4-ethylenedioxy-thiophene) and polystyrene-4-sulfonic acid, and a bar coater is used on a polyethylene terephthalate (PET) film. Then, after applying so that the wet film thickness was 50 μm, it was dried under reduced pressure at 50 ° C. to obtain a conductive film having a film thickness of about 0.2 μm.

-Iron ion content-
Separately from the film formed, the solid content was taken out from the aqueous dispersion, and the amount of iron ions contained by the method was measured. As a result, the iron ion content was 8.0 ppm by mass.

-Transmissivity, surface resistance value-
It was 88% when the transmittance | permeability of this electroconductive film was measured on the said conditions.
On the other hand, the surface resistance value of the formed conductive film was 700Ω / □. Subsequently, the conductive film was irradiated with light for 100 hours with a xenon light source (Suga test machine, light intensity: 180 W / m ² ), and the surface resistance value was measured again. As a result, it was 1400Ω / □.

<Example 2>
In the purification of the conductive polymer of Example 1, SiliaBond TAAcOH (manufactured by SiliCycle, average particle diameter: 50 μm, immobilized) on a silica gel surface with a silane coupling agent instead of SiliaBond Diamine as a carrier. The conductive polymer was purified and evaluated in the same manner as in Example 1 except that the amount: 0.4 mmol% and the spacer part carbon number: 3) were used.
The results are summarized in Table 1.

<Example 3>
In the purification of the conductive polymer of Example 1, 1,5,7-Triazabicyclo (4,4,0) dec-5-ene was immobilized on the silica gel surface with a silane coupling agent instead of SiliaBond Diamine as a carrier. Purification of the conductive polymer in the same manner as in Example 1 except that the carrier SiliaBond TBD (manufactured by SiliCycle, average particle size: 50 μm, immobilization amount: 0.9 mmol%, spacer part carbon number: 3) was used. And evaluated.
The results are summarized in Table 1.

<Example 4>
In the purification of the conductive polymer of Example 1, instead of SiliaBond Diamine as a carrier, SiliaBond Triamine (manufactured by SiliCycle, average particle diameter: 50 μm, immobilization amount: 1 on silica gel surface immobilized with a silane coupling agent) The conductive polymer was purified and evaluated in the same manner as in Example 1 except that .2 mmol% and spacer part carbon number: 3) were used.
The results are summarized in Table 1.

<Example 5>
In the purification of the π-conjugated polymer of Example 1, SiliaBond Thiol (manufactured by SiliCycle, average particle size: 50 μm, immobilization) in which propyl mercaptan was directly immobilized on a silica gel surface via a silane coupling agent instead of SiliaBond Diamine as a carrier The conductive polymer was purified and evaluated in the same manner as in Example 1 except that the amount of the polymer was 1.2 mmol%).
The results are summarized in Table 1.

<Comparative Example 1>
In Example 1, after synthesizing the conductive polymer, evaluation was performed in the same manner as in Example 1 except that the film was formed on a PET film without purification with a chelating agent, and this was used as a sample for evaluation.
The results are summarized in Table 1.

<Comparative Example 2>
In Example 1, a conductive polymer was synthesized and then formed on a PET film without purification. After this conductive film was washed with ethanol, it contained 0.3 mol / L of EDTA-2Na as a chelate compound, 0.4 mol / L of tetraethylammonium-p-toluenesulfonic acid, and was washed at a temperature of 60 ° C. adjusted to pH 5. For 10 minutes and then washed with pure water. This operation was repeated three times to obtain an evaluation sample.
Evaluation was performed in the same manner as in Example 1 using the above sample. The results are summarized in Table 1.

  As shown in the results of Table 1, when purified by the method for purifying a conductive polymer of the present invention, the iron ion concentration in the conductive polymer is considerably lower than those of Comparative Examples 1 and 2, and as a result, transparency In addition to the above, it can be seen that the resistance stability against light irradiation is excellent.

Claims (9)

  A conductive polymer comprising a polymer compound and having an iron ion content of 0.1 to 10 ppm by mass.   The conductive polymer according to claim 1, wherein the polymer compound is a conjugated polymer.   The conductive polymer according to claim 2, wherein the main skeleton structure of the polymer chain is polythiophene.   The conductive polymer according to claim 2 or 3, wherein the structure of the polymer chain is poly (3,4-ethylenedioxy-thiophene). A dispersion preparation step in which a conductive polymer is dispersed in a solvent to form a dispersion;
A dispersion contacting step of bringing the dispersion into contact with a carrier having a chelating agent fixed on the surface;
A method for purifying a conductive polymer, comprising:   The method for purifying a conductive polymer according to claim 5, wherein the carrier is silica gel.   The method for purifying a conductive polymer according to claim 5 or 6, wherein the chelating agent is a compound having at least one selected from an amino group, a carboxy group, a mercapto group, and a nitrogen-containing heterocyclic group. .   The method for purifying a conductive polymer according to any one of claims 5 to 7, wherein the dispersion liquid contains poly (3,4-ethylenedioxy-thiophene) and polystyrene-4-sulfonic acid. .   The method for purifying a conductive polymer according to any one of claims 5 to 8, wherein iron is removed from the conductive polymer.