JPH0586601B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for producing conductive articles useful as electrical and electronic components such as electromagnetic wave shielding materials, solar cells, bonding elements, and electrochemical devices. The present invention relates to a method for producing a conductive article, which comprises molding the article from a conductive polymer solution comprising an oxidized polymer, a dopant, and an organic solvent, and removing the organic solvent. [Prior Art] It is known to obtain a conductive polymer by doping a polymer substance with a dopant, and polyacetylene or polyparaphenylene has been particularly studied in detail. By doping polyacetylene with AsF ₅ etc. as an acceptor and sodium etc. as a donor, p-type and n-type
It is known that conductive polymers of the shape can be obtained. Furthermore, it is known that by selecting and using various dopants from polyphenylene sulfide, polythiophene, polypyrrole, and polyaniline, conductive polymers exhibiting conductivity ranging from electrical insulators or semiconductors to metallic regions can be obtained. It has been revealed that the conductivity can be arbitrarily controlled by adjusting the type of dopant and the amount used. Therefore, these conductive polymers are expected to be used in applications such as solar cells, electrodes, and electrochromic devices. In addition, these known conductive polymers are expected to have a wide range of uses, such as for shielding electromagnetic waves, as comparator control has begun to be used in automobiles, and they are also expected to be applied to various bonding elements and other electronic devices. has been done. [Problems to be Solved by the Invention] However, among the conventionally known conductive polymers mentioned above, for example, polyacetylene, polyparaphenylene, polythiophene, polypyrrole, and polyaniline, these polymers themselves and their doped products There is no solvent that can dissolve both at once, and it is known that for polyparaphenylene sulfide and its doped products, AsF ₃ can be used as a solvent that dissolves both (Japanese Unexamined Patent Publication No. 59-1999).
-11324), AsF ₃ is known to be highly toxic, and furthermore, the electrical conductivity of the polymer solution decreases rapidly in the air, and the product cannot be used as an electrically conductive product. There is a drawback that it cannot be used as a As mentioned above, conventionally known conductive polymers are generally insoluble and infusible, except for certain types of conductive polymers, so they can be melted or melted to produce conductive articles having arbitrary shapes and wall thicknesses. However, it has the disadvantage that the possibilities for doing so are limited, and its applications are also naturally limited. This is an obstacle in researching various applications of conductive polymers.
Solutions to these obstacles have been desired from all quarters. [Means for Solving the Problems] As a result of intensive studies to solve the above-mentioned conventional drawbacks, the present inventors discovered that an oxidized polymer of a specific aniline derivative has excellent solubility in organic solvents, and that this oxidized polymer has excellent solubility in organic solvents. By forming an article from a conductive polymer solution consisting of a dopant and an organic solvent, and removing the organic solvent, the article can have any shape and wall thickness, have high electrical conductivity, and can be made in air. The inventors have discovered that a conductive article with excellent stability can be obtained, and have completed the present invention. That is, the present invention provides general formula (1)

[Formula] [In the formula, R ₁ to _{R 4} may be different or the same and are a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group. However, all of R ₁ to _{R 4} are not hydrogen atoms at the same time. ] The present invention relates to a method for manufacturing a conductive article, which comprises molding an article from a conductive polymer solution consisting of an oxidized polymer of an aniline derivative represented by the following formula, a dopant, and an organic solvent, and removing the organic solvent. The oxidized polymer of aniline derivative used in the present invention is obtained by polymerizing the aniline derivative represented by the general formula (2).

[Formula] [However, R ₁ to _{R 4} are the same as in the above general formula (1). ] It is an organic solvent-soluble polymer containing at least 50 mol% of the repeating unit represented by the formula. If the repeating unit represented by the general formula (2) is less than 50 mol%, the electrical conductivity is insufficient. Specific examples of the aniline derivative having no substituent at the p-position represented by general formula (1) include 2-methoxy-aniline, 3-methoxy-aniline, 2,3-
Dimethoxy-aniline, 2,5-dimethoxy-aniline, 3,5-dimethoxy-aniline, 2,6
-dimethoxy-aniline, 2-ethoxy-aniline, 2-ethoxy-3-methoxy-aniline, 3
-ethoxy-aniline, 2,3-diethoxy-aniline, 2,5-diethoxy-aniline, 2,6
-diethoxyaniline, 3,5-diethoxyaniline, 2,6,-diethoxyaniline, 2-
Methoxy-3-ethoxy-aniline, 2-methoxy-5-ethoxy-aniline, 2,3,6-trimethoxy-aniline, 2,3,5-trimethoxy-aniline, 2,3,5,6-tetramethoxy-
Aniline, 2,3,5,6-tetraethoxy-aniline, 2,3-dimethyl-aniline, 2-methyl-3-methoxy-aniline, 2,3,5,6-
Tetramethyl-aniline, 2-methyl-5-methoxy-aniline, 3,5-dimethyl-aniline,
etc., but are not necessarily limited to these. Among the above-mentioned aniline derivatives, those having two or more substituents are preferable, and in particular, oxidized polymers of alkoxyaniline having two or more alkoxy substituents have good solubility in organic solvents and have good electrical conductivity. It can be preferably used from a high place. The oxidized polymer of aniline derivative may be produced by any method. Examples of oxidized polymers of aniline derivatives include oxidized polymers of aniline derivatives, dopant-containing oxidized polymers doped with a dopant after the production of oxidized polymers of aniline derivatives, and dopants obtained by oxidative polymerization of aniline derivatives in the presence of a dopant. Containing oxidized polymers, etc. Among the above-mentioned oxidized polymers of aniline derivatives, it is preferable to use oxidized polymers that already contain a dopant because there is no need to further blend a dopant when preparing the conductive polymer solution of the present invention. Depending on the amount of dopant contained in the coalescence, a dopant may be further added when preparing the conductive polymer solution. The oxidized polymer of the aniline derivative doped with a dopant can be produced by electrochemically or chemically oxidatively polymerizing the aniline derivative. In the case of electrochemical polymerization, the polymerization of aniline derivatives is carried out by anodic oxidation, with a current of about 0.01 to 50 mA/
cm ² , the electrolytic voltage is usually in the range of 1 to 300 V, and a constant current method, a constant voltage method, and any other method can be used. Polymerization is carried out in an aqueous solution, an alcoholic solvent, or a mixed solvent thereof,
Preferably, it is carried out in an aqueous solution. The alcohol may or may not dissolve the produced oxidized polymer. The alcohol used varies depending on the type of aniline derivative, but methyl alcohol, ethyl alcohol, ethylene glycol, propyl alcohol, butyl alcohol, etc. are usually used. The pH of a suitable electrolytic solution is not particularly limited, but is preferably 3 or less, particularly preferably 2 or less. Specific examples of acids used for pH adjustment include HCl,
Examples include, but are not limited to, HBF ₄ , CF ₃ COOH, HSO ^- ₄ and HNO ₃ . Dopants used when polymerizing the above aniline derivative by electrochemical method include Cl ^- , I ^- ,
Br ^- , F ^- , BF ^- ₄ , ClO ^- ₄ , IO ^- ₄ , AsF ^- ₆ , SbF ^- ₆ ,
PF ^- ₆ , SiF ^- ₄ , AsF ^- ₆ , FSO ^- ₄ , HSO ^- ₄ , SO ₄ ^2- ,
Salts containing CF ₃ SO ^- ₃ , CF ₃ COO ^- , NO ^- ₃ and the like are used, and the resulting oxidized polymer contains these anilines as P-type dopants. These salts contain cations such as alkali metal ions such as lithium, sodium, and potassium, and quaternary ammonium ions. The oxidized polymer thus obtained usually contains 10 to
90 mol % (per monomer unit) of anions are included as dopants. According to the electrochemical method, the oxidized polymer is usually deposited as a black polymer on the anode, and after washing, peeling, and drying, the oxidized polymer is dissolved in an organic solvent and used for various purposes. In the case of chemical polymerization, for example, aniline derivatives can be oxidatively polymerized in aqueous solution with oxidizing strong acids or with a combination of strong acids and peroxides such as potassium persulfate. Since the oxidized polymer obtained by this method can be obtained in powder form, it can be separated and dried before use. In this case too, the oxidized polymer is obtained doped with the corresponding anion. The resulting oxidized polymer usually contains 10 to 90 mol % (per monomer unit) of an anion as a dopant. The oxidized polymer of anionic derivative obtained by separation and drying is
The polymer is dissolved in a soluble organic solvent to obtain a polymer solution, which can be used for various purposes. As the dopant used in the present invention, the same dopants as those used in the oxidative polymerization of aniline derivatives are used. The amount of dopant to be blended depends on whether the oxidized polymer of the aniline derivative used contains the dopant in advance,
Although it cannot be determined unconditionally because it differs depending on whether the aniline derivative is contained or not, it is usually blended so that the proportion of the dopant in the oxidized polymer of the aniline derivative is 10 to 90 mol% (per monomer unit). The organic solvent used to dissolve the oxidized polymer of the aniline derivative varies depending on the type of the oxidized polymer of the aniline derivative used, so it cannot be specified specifically, but it must be one that can dissolve the oxidized polymer of the aniline derivative. Aliphatic and aromatic ketones, ethers, esters, amides, nitriles, carbonates, carboxylic acids, halogen compounds, sulfolane compounds, nitro compounds, sulfoxides, lactams, lactones , saturated and unsaturated heterocyclic compounds. Aliphatic and aromatic ketones include acetone, diethyl ketone, methylpropyl ketone, hydroxyacetone, methoxyacetone, phenylacetone, 4-phenylbutanone-2, etc.; ethers include tetrahydrofuran, dioxane, dimethyl ether, diethyl ether , methyl-ethyl ether, dimethoxyethane, diethoxymethane, methyl glycol, anisole,
1,2-dimethoxybenzene, 1,4-dimethoxybenzene, 1,3-dioxolane, etc.; As esters, methyl acetate, ethyl acetate, trimethyl orthoformate, ethyl oxalate, trimethyl phosphate, etc.; as amides Examples of nitriles include formamide, N-methylformamide, dimethylformamide, N-methylacetamide, dimethylacetamide, N-methylpropioamide, hexamethylphosphoramide, etc.
Acetonitrile, valeronitrile, benzonitrile, etc.; Carbonates include propylene carbonate, ethylene carbonate, dimethyl carbonate, etc.; Carboxylic acids include formic acid, acetic acid, benzoic acid, oxalic acid, etc.; Halogen compounds include chloroform, carbon tetrachloride, etc. , chlorobenzene, dichlorobenzene, benzoyl chloride, benzoyl bromide, benzenesulfonyl chloride, benzenesulfonyl dichloride, benzenethiophosphonyl chloride, methanesulfonyl chloride, acetyl chloride, dimethylsulfamyl chloride, ethyloxalyl chloride, chlorosulfonylacetyl chloride, etc.; Examples of sulfolane compounds include sulfone and 3-methyl-sulfolane; examples of nitro compounds include nitromethane and nitrobenzene; examples of sulfoxides include dimethyl sulfoxide; examples of lactams include N-methylpyrrolidone; examples of lactones include: γ-butyrolactone, etc.; examples of saturated and unsaturated heterocyclic compounds include tetrahydrothiophene, 3-methyl-2-oxazolidone, pyrrole, 1-methylpyrrole, 2,4-dimethylthioazole, furan, etc. Ru. Methods for preparing the conductive polymer solution of the present invention include () a method of dissolving an anion-doped oxidized polymer obtained by electrochemical oxidative polymerization in the above-mentioned organic solvent; () a method obtained by chemical oxidative polymerization; A method of dissolving an oxidized polymer doped with a chemically synthesized anion in the above-mentioned organic solvent; Examples include a method of dissolving in an organic solvent, and a method of dissolving a chemically synthesized oxidized polymer that is not doped with an anion in the above-mentioned organic solvent, and adding a dopant to this solution. The method is not limited. The concentration of the oxidized polymer of the aniline derivative in the polymer solution is not particularly limited, but is usually used in the range of 0.01 to 90% by weight. The conductive heavy body solution thus obtained contains metals,
Conductive coatings can be applied to various solid surfaces such as semiconductors, synthetic resins, ceramics, and paper fibers by coating, spraying, or depositing the surfaces, and then removing the organic solvent. Conductive articles can be manufactured. Further, the conductive polymer solution can be cast and dried in batches or continuously to produce a conductive film of a desired thickness. Furthermore, conductive fibers or films can be produced by extruding the conductive polymer solution through a die. Similarly, conductive articles in the form of molds can be produced by casting conductive polymer solutions into molds of various shapes and removing organic solvents from the conductive polymer solutions within the molds. can. In the present invention, the term "conductive article" includes the above-mentioned solid articles whose surfaces are coated with a conductive polymer, conductive films, conductive fibers, cast products, and the like. The method for removing the organic solvent is not particularly limited, but it can be carried out by commonly used methods such as vacuum or reduced pressure deaeration, heat drying, forced ventilation, and air drying. The conductive coating film obtained in this way,
The electrical conductivity of the fibers and cast products is 10 ^-5 to 10 ² s/cm ² . [Effects of the Invention] According to the method of the present invention, since the conductive polymer solution used is non-toxic, workability is excellent, and conductive articles of any shape can be easily manufactured. Since the conductive articles obtained by the method of the present invention are stable in the air and have high electrical conductivity, they can be used as electromagnetic shielding materials, solar cell junction elements, electrochromic elements, and other electronic components. It is very useful industrially. [Example] Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 20 ml of a 1.5 mol HBF ₄ aqueous solution and 0.35 mol 2,5-dimethoxy-aniline were placed in a glass reaction vessel to prepare an aqueous solution with a pH<1.0. In this aqueous solution, electrodes with an area of 10 cm ² are placed at 2 cm intervals.
After inserting two platinum electrodes, electrolytic polymerization was carried out by flowing 20 clones of electricity under stirring. At this time, a black oxidized polymer was deposited on the platinum electrode of the anode.
After the electrolytic polymerization was completed, the coated anode was washed with distilled water and vacuum dried at 70°C. Next, the polymer was peeled off from the platinum electrode and dissolved in an acetonitrile solvent to produce a polymer solution having a polymer concentration of 10% by weight. Infrared spectroscopy and NMR revealed that this polymer contained 80 mol% or more of repeating units having the structure of general formula (2). The resulting polymer solution was applied onto a glass plate and then vacuum degassed to produce a casting film. The electrical conductivity of this film at room temperature (DC four terminal method) is 2.5×10 ^-1 s/cm,
In addition, elemental analysis revealed that 2.5-dimethoxy-aniline 1
It was found that 0.45 mol/mol of BF ^- ₄ was doped. The resulting film was left in the air for one month, and its electrical conductivity was measured again: 2.2×
At 10 ^-1 s/cm, the electrical conductivity remained almost unchanged. Examples 2 to 4 2,5 used as the aniline derivative in Example 1
Electrolytic polymerization was carried out in exactly the same manner as in Example 1 except that the aniline derivatives shown in the table were used instead of -dimethoxy-aniline to prepare a polymer solution,
I also got a casting film. The physical properties of the resulting casting film are shown in the table. Furthermore, according to the infrared spectrum and NMR, each polymer contains 80 mol% of repeating units with the structure of general formula (2).
It included the above.

[Table] Comparative Example An oxidized polymer of aniline was obtained by electropolymerization in exactly the same manner as in Example 1, except that aniline was used instead of 2,5-dimethoxy-aniline used in Example 1. , this polymer was insoluble in organic solvents. Example 5 Chemical synthesis of poly-2,5-dimethoxy-aniline 1 Production of monomer: Under Ar, Zn powder was added and recrystallization was performed with ethanol. 2 Polymerization: Attach a thermometer, stirrer, and condenser to the small-necked flask from 1, and add 1 normal
500 ml of HBF ₄ aqueous solution was added and cooled to 22°C on ice. To this was dissolved 33.62 g of 2,5-dimethoxy-aniline (0.2195 mol). To this, while stirring, ammonium persulfate 11.5g
(0.05 mol) was added as a solid, and within 2 minutes after addition, a blue color began to form and a dark blue precipitate formed. Since this was an exothermic reaction, the reaction solution was kept at 22°C by cooling with ice during this time. After reacting for 1 hour, the reaction solution was filtered, and the residue was washed with 250 ml of 42% _HBF4 aqueous solution for 10 minutes under normal pressure.
Passed under reduced pressure. Add this residue to 500ml of distilled water.
Place in strong vacuum for 10 min. Example 1 from elemental analysis and IR measurement of this product
It was found that it has the same composition and structure as poly-2,5-dimethoxy-aniline obtained by electrolytic polymerization. In addition, from the results of elemental analysis, this oxidized polymer has a
It was found that 0.49 mol of BF ^- ₄ was doped. A polymer solution was prepared in exactly the same manner as in Example 1, except that the oxidized polymer obtained by the above method was used, and a casting film was also obtained. The electrical conductivity of this casting film is 1.9
×10 ^-1 s/cm. Further, after the obtained film was left in the air for one month, the electrical conductivity was measured again and it was found to be 1.8×10 ^-1 s/cm.

Claims (1)

[Claims] 1 General formula (1) [Formula] [In the formula, R ₁ to _{R 4} may be different or the same and are a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group . However, all of R ₁ to _{R 4} are not hydrogen atoms at the same time. ] A method for manufacturing a conductive article, which comprises molding an article from a conductive polymer solution comprising an oxidized polymer of an aniline derivative represented by the formula, a dopant, and an organic solvent, and removing the organic solvent. 2 An oxidized polymer of an aniline derivative has the general formula (2) [Formula] [In the formula, R ₁ to R ₄ may be different or the same, and are a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group. be. However, all of R ₁ to _{R 4} are not hydrogen atoms at the same time. ] The method for producing a conductive article according to claim 1, which is an organic solvent-soluble polymer containing at least 50 mol% of repeating units represented by the following. 3. The method for producing a conductive article according to claim 1, wherein the oxidized polymer of the aniline derivative is an organic solvent-soluble dopant-containing oxidized polymer produced by an electrolytic oxidative polymerization method. . 4 The oxidized polymer of aniline derivative is an oxidizing strong acid,
or an organic solvent-soluble dopant-containing oxidized polymer produced by a chemical oxidative polymerization method using a combination of a strong oxidizing acid and a peroxide. Method of manufacturing the article. 5 Dopants are Cl ^- , I ^- , Br ^- , F ^- , BF ^- ₄ ,
ClO ^- ₄ , IO ^- ₄ , SbF ^- ₆ , PF ^- ₆ , SiF ^- ₄ , AsF ^- ₆ , HSO ^- ₄ ,
Claim 1, characterized in that it is at least one electron-accepting dopant selected from the group consisting of FSO - 4 , SO ₄ ^2- , CF ₃ SO ^- ₃ , CF ³ _COO ^- and _NO ^- ₃ A method for producing a conductive article according to item 1. 6 Ketones, ethers, esters, amides, nitriles, carbonates, carboxylic acids, halides, sulfolane compounds, nitro compounds, sulfoxides, lactams, and lactones in which the organic solvent is aliphatic or aromatic 2. The method for producing a conductive article according to claim 1, wherein the conductive article is a saturated or unsaturated heterocyclic compound, or a mixture of two or more thereof. 7. Degas the organic solvent under vacuum or reduced pressure, heat dry,
The method for manufacturing a conductive article according to claim 1, wherein the removal is carried out by strong ventilation or air drying.