JP3144808B2 - Method for producing conductive organic polymer fiber or film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a conductive organic polymer fiber or film.

[0002]

2. Description of the Related Art Conductive organic polymers are expected to have a wide range of applications as conductive materials or materials for batteries and the like. Research is being developed. Conventional research has focused on further increasing the conductivity of the conductive polymer to a practical level, and the processing method has been postponed.

As a method for producing a highly conductive organic polymer, an electrolytic oxidation polymerization method and a chemical oxidation polymerization method are known. In the electrolytic oxidation polymerization method, a monomer to be polymerized with a supporting electrolyte is dissolved in an appropriate solvent, and a constant voltage is applied between inserted electrodes to form a conductive polymer on an anode plate. Depending on the type of monomer used, the polymer obtained in this way can further increase the conductivity of several tens to several thousand S / cm by selecting optimum conditions such as a solvent, an electrolyte, an applied voltage, and a current value. Can be obtained, and is suitable as a method for obtaining a highly conductive polymer. Moreover, since a polymer is formed on the electrode plate, there is an advantage that the polymer can be obtained in a film form.

On the other hand, the chemical oxidative polymerization method is a method of oxidizing and polymerizing a monomer using an oxidizing agent, and the production method is roughly divided into two methods. One is a method in which, for example, a monomer is dissolved in a suitable solvent and polymerized with a suitable oxidizing agent. In this method, compared to the electrolytic oxidation polymerization method, a polymer can be obtained inexpensively and the productivity is high, but generally the conductivity is low, the polymer is obtained as a powder, and the polymer is generally insoluble and infusible. It has the disadvantage of being extremely poor in moldability.

As another method, there is a method in which a monomer deposited on a substrate is polymerized with an oxidizing agent to form a conductive thin film. However, in the prior art, there is also a problem in this case that the conductivity of the produced polymer is not high.

The present inventors have been studying the improvement of the chemical oxidative polymerization method in order to solve these problems. So far, selection of a solvent and use of an oxidizing agent to control the oxidation potential during the oxidative polymerization reaction have been performed. Conductivity can be improved by selection (Japanese Patent Application No. 63-55659), and a molded product with improved moldability and conductivity can be obtained by adding a small amount of solvent during polymer molding. What you can do (Japanese Patent Application No. 63-85706) and CVD
It is possible to obtain a highly conductive polymer film by selecting an appropriate combination of a solvent and an oxidizing agent when preparing a polymer film by the oxidative polymerization method (Japanese Patent Application No. 63-175969). At the time of forming a coalesced film, a highly conductive polymer film can be prepared by performing polymerization while evaporating and removing a solvent from a solution containing a monomer, a binder polymer, and an appropriate concentration of an oxidizing agent (Japanese Patent Application No. Hei 10-26139). 2-183445). However, in the range of the prior art, a method for continuously producing fibers or films, which is an essential technique for mass production, has not been solved.

[0007]

Means for Solving the Problems The present inventors have used an aromatic compound, particularly an aromatic compound containing heteroatoms such as nitrogen, oxygen, and sulfur, and obtained a highly conductive organic polymer by a chemical oxidative polymerization method. As a result of intensive research to obtain coalescence, the adoption of a special manufacturing method has resulted in continuous and inexpensive organic polymer fibers or films that have high electrical conductivity and excellent solvent resistance and tensile strength. The present invention has been found, and the present invention has been achieved.

That is, in the present invention, in producing a conductive organic polymer fiber or film, a mixed solution of a monomer and a binder polymer or a solution in which both are dissolved in a common solvent is mixed with a solution containing an oxidizing agent. The method for producing a conductive organic polymer fiber or film, characterized in that chemical oxidation polymerization is performed by extruding while controlling the oxidation potential of the solution containing the agent, in the present invention,
The monomer and the binder polymer are extruded into a fibrous or film form into a solution containing an oxidizing agent, and the monomer is oxidized and polymerized to form a conductive polymer.At the same time, the binder polymer is cross-linked to form a fiber or film insoluble in a solvent. Is what you do. At this time, if the oxidation potential is controlled by selecting the solvent and adjusting the oxidizing agent concentration, the conductivity of the polymer increases.

The monomer used in the present invention is selected from those which form a conjugated system by oxidative polymerization. Examples of such compounds include pyrrole derivatives, furan derivatives and thiophene derivatives in the case of 5-membered heterocyclic compounds.

[0010] Suitable compounds as pyrrole derivatives have unsubstituted pyrrole, N- alkyl pyrroles such as N- substituted pyrrole or 3-position or 3,4-position an alkyl group C ₁ ~C _6,, alkoxy group or a halogen atom Examples include 3-alkylpyrrole, 3,4-dialkylpyrrole, 3-alkoxypyrrole, 3,4-dialkoxypyrrole, 3-chloropyrrole, and 3,4-dichloropyrrole. The furan derivatives and thiophene derivatives unsubstituted furan, and 3-positions or 3,4-position an alkyl group C ₁ -C _6,
3-alkylfuran having an alkoxy group or a halogen atom, 3,4-dialkylfuran, 3-alkoxyfuran,
3,4-dialkoxyfuran, 3-chlorofuran or 3,4-
Dichlorofuran or the like, or unsubstituted thiophene, and 3-alkylthiophene having a C _{1 to} C ₆ alkyl group, alkoxy group, or halogen atom at the 3- or 3-position, 3,4-dialkylthiophene, 3-alkoxythiophene , 3,4-dialkoxythiophene, 3-chlorothiophene, and 3,4-dichlorothiophene. Examples of the six-membered aromatic compound include aniline and benzidine.

As the oxidizing agent used in the present invention, an oxidizing agent having an oxidation potential similar to that of an electrolytic oxidation polymerization method for producing a highly conductive polymer in a reaction medium is preferable.
For example, oxidants for pyrrole, furan, and thiophene include iron (III) salts, molybdenum (V) salts, and ruthenium.
(III) salts and the like. The oxidizing agents for aniline and benzidine include chromate (IV), bichromate (VI) and permanganate (VII).

As a specific example of the present invention, a method for producing a conductive polymer when the monomer is pyrrole will be described in detail.

Specific examples of the oxidizing agent include FeCl ₃ , Fe (ClO
_{4) 3} or the like of Fe (III) _{salts, RuCl 3, Ru (ClO 4} ) _3, etc. Ru (III)
Salts or Mo (V) salts such as MoCl ₅ and Mo (ClO ₄ ) ₅ are mentioned. Of these, Fe (III) salts, especially
Preferably, FeCl ₃ is used.

In the present invention, a homogeneously dispersed mixture of a monomer and a binder polymer is extruded into a solution containing an oxidizing agent. At this time, if the extruded material is stretched while being extruded from the pores, a fiber is obtained, and if extruded from the slit, a film is obtained.

As the binder polymer, a polymer that dissolves the monomer at room temperature or in a heated (melted) state is preferable. However, the polymer remains in a solid state even when heated, or has no compatibility even if it is a liquid. If uniform mixing is difficult for reasons such as the above, a solvent may be used to homogenize the mixing. When the monomer is pyrrole, as a vinyl polymer, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyacrylonitrile, polymethyl methacrylate, polyvinyl alcohol, polyvinyl acetate, etc., and as a polyester, polyethylene terephthalate (PET), polybutylene terephthalate (PBT) )
, Polycarbonate, etc., polyamides such as polyamide 6, polyamide 6.6, polyamide 12, polyamide 6
10 and the like, and polyimide, polyethylene oxide and the like can be used. These polymers may be used in the form of a copolymer or a blend of several kinds. In the present invention, since these binder polymers eventually become insoluble crosslinked products, low molecular weight ones such as oligomers or hygroscopic ones can also be used. Among them, polystyrene, polyacrylonitrile and the like are particularly advantageous in that a solvent can be easily selected.

The solvent for dissolving the oxidizing agent must be selected from those which are well soluble in the solvent used for mixing the monomer and the binder polymer and do not dissolve the binder polymer. That is, for example, when the binder polymer is polystyrene, water, or alcohols such as methanol and ethanol, acetones, and when polyacrylonitrile is water, various alcohols, various ethers, etc., are polyamides. At times, water or aliphatic alcohols such as methanol and ethanol, chloroform and the like, and polyesters, that is, PET, PB
For T and the like, water, various alcohols, acetone, and ethers can be used.

According to the study of the present inventors, the conductivity of the produced polymer largely depends on the oxidation potential during oxidative polymerization.
The oxidation potential can be controlled by selecting the type of solvent, the oxidizing agent concentration, and the temperature. The simplest method is to control the potential by the oxidant concentration.However, the optimum potential is often obtained in a region where the oxidant concentration is low.In such a case, the potential becomes unstable as the oxidation reaction proceeds. Cheap. In such a case, keep the oxidative polymerization concentration high,
Further, by adding an appropriate amount of a reduced form of the oxidizing agent, a solution having an optimum potential and having a stable potential can be prepared. When the monomer is pyrrole, the oxidation potential is 400
900900 mV (vs. SCE), preferably 450 to 800 mV (vs. SCE) is suitable. That is, when the oxidation potential is within this range, a high conductivity is obtained. However, when the oxidation potential is out of the range, the conductivity of the product is extremely reduced and is not suitable for practical use. The same is true for other monomers, for example, when the monomer is thiophene, 900-1600 mV (vs. SCE), preferably 1000-1500 mV (vs. SCE), when furan is 1450-
1900mV (vs. SCE), preferably 1500-1800mV (vs. SC
E), when it is aniline, 700-1300 mV (vs. SCE), preferably 800-1200 mV (vs. SCE), when it is benzidine,
750-1300mV (vs. SCE), preferably 800-1200mV (v
Only when there is an oxidation potential in the range of s. SCE) does the product become more conductive.

The mixture of the monomer and the binder polymer extruded into the oxidizing agent solution is allowed to stand for an appropriate period of time so that the polymerization reaction is sufficiently performed. Thereafter, the residual oxidizing agent is sufficiently washed and removed, and then dried to obtain a target product. The obtained fiber may be annealed by heating after drying.

Further, according to the present invention, the above polymer is chemically or electrochemically reduced, and then chemically or electrochemically oxidized and doped, whereby
The conductivity of polypyrrole can be further increased. Examples of the reducing agent used for chemical reduction include hydrazines such as hydrazine, hydrazine hydrate and phenylhydrazine, and metal hydrides such as lithium aluminum hydride and sodium borohydride. The chemical reducing agent is usually used in an amount of 1 to 10 times per nitrogen atom of the polymer, but is not necessarily limited thereto. In electrolytic reduction, the resulting conductive fiber or film is used as a cathode and dedoped by electrolysis at an applied voltage of 0.01 to several tens V, usually several volts.

After the reduction, the neutral polypyrrole is again chemically reoxidized with an oxidizing agent and doped.
As the dopant used for such re-doping, any compound having sufficient oxidizing power to re-oxidize the reduced neutral polymer and having an effective electron-accepting property as a dopant can be used. Such oxidizing agents include iodine, bromine, halogens such as chlorine, arsenic pentafluoride, antimony pentafluoride, boron trifluoride, boron trichloride, ferric chloride, stannic chloride, titanium tetrachloride,
Lewis acids such as zinc chloride and cupric chloride, hydrochloric acid, sulfuric acid and its salts (eg, potassium hydrogen sulfate and sodium hydrogen sulfate), iron perchlorate and the like, or borofluoric acid and its salts (eg, sodium borofluoride) , Potassium boron fluoride, ammonium boron fluoride, tetraalkylammonium boron fluoride) and the like, but are not necessarily limited thereto.

It is also possible to perform oxidation and doping electrochemically again. In this case, the above oxidizing agent may be dissolved as a supporting electrolyte, and electrolysis may be performed using polypyrrole as an anode.

[0022]

According to the present invention, highly conductive organic polymer fibers or films can be easily produced by chemical oxidative polymerization, and the fibers produced in this manner can be used for lightweight electric wires, conductive fillers and the like. The film can be used as a capacitor electrode, a battery, an electrode material, and a conductive film.

[0023]

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

Examples 1-4, Comparative Example 1 A pyrrole monomer and a low-molecular-weight polystyrene were kneaded at a weight ratio of 1: 1 to prepare a liquid mixture. While being extruded into a methanolic solution of ferric chloride having the following formula: The obtained fiber was wound in this solution, and oxidative polymerization was allowed to proceed as it was. After each reaction time, the fiber was taken out, washed with methanol to remove ferric chloride, and dried in vacuum at room temperature. Thereafter, the conductivity of these fibers was measured, and the fibers were immersed in ethanol, acetone, and benzene for 24 hours, and the property change was observed thereafter. The results are collectively shown in Table 1. When the oxidation potential was within an appropriate value range, a high conductivity was obtained, but when the oxidation potential was out of the range, the conductivity sharply decreased. The solvent resistance is
も の indicates no change in properties, and ○ indicates swelling with some or all of the solvent.

Example 5, Comparative Example 2 In Comparative Example 1, 0.3 mol / l of ferrous chloride was further added to the oxidizing agent solution, and spinning was carried out in the same manner as in Example 1, and further evaluated. In this case, the addition of the reductant of the oxidizing agent brought the oxidation potential to an appropriate value and showed high conductivity. On the other hand, in the solution showing the proper oxidation potential in Example 1,
When 1.0 mol / l ferrous chloride was added, the oxidation potential
It decreased to 350 mV (Comparative Example 2). When spun in this solution, the conductivity of the product dropped sharply. Table 2 shows the results
Shown in

Examples 6 to 8 A polymerization reaction was caused in a system in which the monomer was pyrrole by changing the binder polymer. Example 6: 1 part by weight of pyrrole and 3 parts by weight of polyacrylonitrile as a binder polymer were dissolved in 12 parts by weight of dimethylformamide (DMF). Example 7: 1 part by weight of pyrrole and 3 parts by weight of polyethylene terephthalate (PET) were dissolved in 12 parts by weight of hexafluoroisopropanol (HFIP). Example 8: 1 part by weight of pyrrole and 3 parts by weight of low molecular weight polyamide 66 were dissolved in 12 parts by weight of dimethyl sulfoxide (DMSO). On the other hand, a 4 mol / l ferric chloride aqueous solution (oxidation potential 700 m
V) was prepared, and the mixed solutions of Examples 6 to 8 were spun and evaluated in the same manner as in Example 1. The results are summarized in Table 3.

Examples 9 to 11 Monomers other than pyrrole were studied. Example 9: 1 part by weight of thiophene and polystyrene 3
Parts by weight were dissolved in 12 parts by weight of THF. On the other hand, a 1 mol / l acetonitrile solution of ferric chloride was prepared, and the thiophene solution was spun in this oxidizing agent solution as in Example 1. Example 10: 1 part by weight of thiophene and 3 parts by weight of polyacrylonitrile were dissolved in 12 parts by weight of DMF. On the other hand, a solution in which chloroform was saturated with molybdenum pentachloride was prepared, and the thiophene solution was spun in this solution as in Example 1. Example 11: 1 part by weight of aniline and 3 parts by weight of polystyrene were dissolved in 12 parts by weight of THF. On the other hand, a 4 mol / l aqueous solution of potassium dichromate was prepared, and the aniline solution was spun in this aqueous solution in the same manner as in Example 1. Table 4 summarizes the results of the measurements of the conductivity and the solvent resistance of the products of Examples 9 to 11.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

[Table 3]

[0031]

[Table 4]

Example 12 A film was prepared by mixing pyrrole with polystyrene at a weight ratio of 1: 1 and applying pressure to extrude through a slit having a width of 50 μm and a length of 5 cm into a 4 mol / l aqueous solution of ferric chloride. .
The obtained film was left in the solution for 30 minutes, and was subjected to oxidative polymerization as it was. Thereafter, the film was taken out and washed with methanol to remove an excess oxidizing agent, followed by vacuum drying at room temperature. The conductivity of the film obtained in this example was measured by a four-terminal method and found to be 15 S / cm. The film was immersed in ethanol, acetone, and benzene for 24 hours, and changes in properties were observed, but no change in shape such as shrinkage or swelling was observed.

Example 13 The fiber having a conductivity of 20 S / cm prepared in Example 2 was immersed in a solution of phenylhydrazine (200 mg) in ether (10 ml) and reacted at room temperature with stirring for 1 hour. After the reaction, the film was sufficiently washed with ether and dried under vacuum. The film was doped by exposure to iodine vapor for 10 hours in a desiccator at room temperature. When the conductivity of this re-doped film was measured, it was found to be 40 S / cm, indicating an increase in conductivity.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI D01F 6/54 D01F 6/54 B 6/56 6/56 6/80 311 6/80 311Z 6/84 306 6/84 306B 306D // C08L 65:00 (56) References JP-A-2-127423 (JP, A) JP-A-1-306608 (JP, A) JP-A 1-272824 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08J 5/00-5/24 C08G 61/00-61/12

Claims (6)

(57) [Claims] When producing a conductive organic polymer fiber or film, a mixed solution of thiophene and a binder polymer or a solution in which both are dissolved in a common solvent contains the oxidizing agent in a solution containing the oxidizing agent. A method for producing a conductive organic polymer fiber or film, comprising extruding a solution while controlling the oxidation potential of the solution to 900 to 1600 mV (vs. SCE) to cause chemical oxidation polymerization. 2. The method according to claim 1, wherein the oxidizing agent is iron (III) salt or molybdenum.
(V) The conductive organic polymer fiber according to claim 1, which is selected from a salt.
Manufacturing method of fiber or film. 3. A conductive organic polymer fiber or film.
Aniline-based or benzidine-based
Mixed solution of the compound and binder polymer, or both
Solution in a common solvent into a solution containing an oxidizing agent.
Extrusion while controlling the oxidation potential of the solution containing the oxidizing agent
Conducting organic oxidative polymerization by conducting
A method for producing polymer fibers or films. 4. The method according to claim 1, wherein the oxidizing agent is chromate (IV), bichromate (VI).
4. The method according to claim 3, which is an acid salt or permanganate (VII) acid salt.
A method for producing a conductive organic polymer fiber or film. 5. When the monomer is aniline, an oxidizing agent is used.
When the oxidation potential of the containing solution is in the range of 700 to 1300 mV (vs. SCE)
The conductive organic polymer fiber according to claim 3 or 4.
Or a method of manufacturing a film. 6. A conductive organic polymer fiber or film.
In the production of
A mixed solution or a solution in which both are dissolved in a common solvent
Of the solution containing the oxidizing agent in the solution containing the oxidizing agent.
Extruded while controlling the position and chemically oxidized and polymerized.
Conductive organic polymer fiber or film
Later, when oxidized by an oxidizing agent effective as an acceptor
Conductive organic polymer fibers or fibers that are co-doped
Film manufacturing method.