JP2903038B2 - Aniline-based conductive polymer and method for producing the same - 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 an aniline-based conductive polymer soluble in a solvent.

[0002]

2. Description of the Related Art Doped polyaniline, which is well known as a conductive polymer, is insoluble in almost all solvents and has problems in molding and processing. Then, in recent years, a water-soluble sulfonated polyaniline exhibiting conductivity without adding a dopant and a method for synthesizing the same have been proposed. For example, as a method for synthesizing a sulfonated polyaniline, a method for synthesizing a sulfonated polyaniline by electrochemically polymerizing aniline and m-aminobenzenesulfonic acid (Journal of the Chemical Society of Japan, 1985, 1124, JP-A-02-1)
No. 66165), a method of synthesizing sulfonated polyaniline by chemically polymerizing aniline and o- and m-aminobenzenesulfonic acid (Japanese Patent Application Laid-Open No. 01-301714), polymerizing chemically or electrochemically. A method of sulfonating an emeraldine type polymer (polyaniline) obtained by using concentrated sulfuric acid (JP-A-58-21090).
2), a method of sulfonation using a sulfuric anhydride / triethyl phosphate complex (JP-A-61-197633), and a method of sulfonation with fuming sulfuric acid (J. Am. Chem. S)
oc. 1991, 113, 2665-2671;
Am. Chem. Soc. , 1990, 112, 280
0, WO91-06887) and the like.

[0003]

2. Description of the Related Art A method of synthesizing a sulfonated polyaniline by electrochemically polymerizing aniline and m-aminobenzenesulfonic acid (Journal of the Chemical Society of Japan, 1985, 1124;
Japanese Patent Application Laid-Open No. 02-166165) has a problem that the isolation operation is complicated and mass synthesis is difficult because the product is formed on the electrode. JP-A-01-30
When the present inventors supplemented the method of chemically polymerizing aniline and m-aminobenzenesulfonic acid with ammonium persulfate described in JP-A-1714, the inventors found that about one sulfonic acid group was introduced into five aromatic rings. Was only done. Also, when sulfonated by the method disclosed in JP-A-61-197633, the solubility of polyaniline in the sulfonated solvent is not sufficient and the reaction is carried out in a dispersed state, as described on page 7 of the publication. Only about one sulfonic acid group is introduced into five aromatic rings. The sulfonated polyaniline having a small sulfonic acid group introduction ratio thus obtained is
There is a problem that conductivity and solubility are not sufficient. Also, J.I. Am. Chem. Soc. , 1991, 11
3, 2665 to 2671; Am. Chem. So
c. , 1990, 112, 2800, when polyaniline is sulfonated with fuming sulfuric acid, about one sulfonic acid group is introduced into two aromatic rings. However, when polyaniline is sufficiently sulfonated by the present method, a large excess of fuming sulfuric acid is required because the solubility of polyaniline in fuming sulfuric acid is not sufficient. Also,
When polyaniline is added to fuming sulfuric acid, there is a problem that the polymer is easily solidified. Therefore, it is necessary to find a method of introducing more sulfonic acid groups into an aromatic ring in order to develop conductivity and improve solubility without adding a dopant to a polymer. Further, in consideration of moldability such as film formation by coating, it is desirable to have solubility in water and an organic solvent in order to be able to apply to both hydrophilic and hydrophobic substrates. However, the sulfonated polyaniline has solubility in water, but does not have sufficient solubility in an organic solvent. As a method for solving these various problems, the present inventors have proposed aniline, N-
An aniline-based compound comprising copolymerizing at least one compound (A) selected from the group consisting of alkylanilines and phenylenediamines with aminobenzenesulfonic acid (B), and sulfonating with a sulfonating agent. Proposal of a method for producing a copolymer sulfonated product
No. 178989). However, this method also requires an operation of sulfonating in concentrated sulfuric acid, and treatment of waste acid remains as a major problem.

[0004]

SUMMARY OF THE INVENTION The present invention relates to an aniline which exhibits high conductivity, improves solubility in water and organic solvents and coatability, and eliminates a sulfonation operation which generates a large amount of acid waste. An object of the present invention is to provide a method for producing a system conductive polymer.

[0005]

The present inventors have intensively studied sulfonated polyaniline having a high ratio of introducing a sulfonic acid group to an aromatic ring as a polyaniline having high conductivity and solubility and a method for producing the same. As aminobenzenesulfonic acid (the aforementioned Japanese Patent Application No. 3-36022).
6) a compound having an alkoxy group on the aromatic ring
That is, the use of alkoxy group-substituted aminobenzenesulfonic acids particularly improves the reactivity, improves the introduction ratio of sulfonic acid groups in the polymer, and finds that various sulfonation operations conventionally proposed can be omitted. It has been completed. A first aspect of the present invention is to form at least one compound (A) selected from aniline, N-alkylaniline and phenylenediamines and an alkoxy-substituted aminobenzenesulfonic acid (B) into (A):
The present invention relates to a water-soluble and organic solvent-soluble aniline-based conductive polymer obtained by copolymerizing (B) at a weight ratio of 8: 2 to 1: 9. The conductivity is such that the surface resistance value is 5
× 10 ⁹ Ω / □ or less, and particularly preferably 8.0 × 10 ⁷ Ω / □ or less. In the second aspect of the present invention, aniline, N-
At least one compound (A) selected from alkylanilines and phenylenediamines and an alkoxy-substituted aminobenzenesulfonic acid (B) are used in a weight ratio of (A) :( B) of 8: 2 to 1: 9. The present invention relates to a method for producing a water-soluble and organic solvent-soluble aniline-based conductive polymer, characterized by copolymerizing with an oxidizing agent in a solution at a temperature of -5 to 70 ° C.

[0006] The term "soluble" means that the aniline-based conductive polymer is soluble in a 0.3N ammonium aqueous solution at room temperature at room temperature. Solubility of 20 mg / ml or more,
The solubility in an organic solvent is preferably 30 mg / ml or more.
The solubility when dissolved in a N ammonium alcohol solution at room temperature is 5 mg / ml or more, preferably 10 mg / ml.
ml.

The N-alkylaniline includes N-alkylaniline.
Methyl aniline, N-ethyl aniline, N-n propyl aniline, N-iso propyl aniline, N-butyl aniline and the like can be mentioned, and the phenylenediamines include phenylenediamine, N-phenylphenylenediamine, N, N ' -Diphenylphenylenediamine, N-
Refers to aminophenyl-N'-phenylphenylenediamine and the like. Aniline, N-alkylaniline, and phenylenediamines are used alone or as a mixture.

The ratio (weight) of N-alkylaniline to aniline and / or phenylenediamine is preferably 0 to 30 for N-alkylaniline with respect to 100 total amount of aniline and / or phenylenediamine. is there. If the proportion of the N-alkylaniline is too large, the solubility in water is reduced and the conductivity tends to be poor. Aniline and phenylenediamines are
Each of them may be used alone or mixed at an arbitrary ratio. In general, when copolymerized with aminoanisolesulfonic acids using only aniline, the introduction ratio of sulfone groups is lower than when phenylenediamines such as phenylenediamine and N-phenylphenylenediamine are used. , Conductivity tends to be good.

The most representative of the alkoxy-substituted aminobenzenesulfonic acids are aminoanisolesulfonic acids, which are 2-aminoanisole-3-sulfonic acid and 2-aminoanisole-4-sulfonic acid. Acid, 2-aminoanisole-5-sulfonic acid, 2-aminoanisole-6-sulfonic acid, 3-aminoanisole-2-sulfonic acid, 3-aminoanisole-4-sulfonic acid, 3-aminoanisole-5-sulfone Acid, 3-aminoanisole-6-sulfonic acid, 4-aminoanisole-2-sulfonic acid, 4-
Aminoanisole-3-sulfonic acid includes those in which the methoxy group of this anisole is substituted by another alkoxy group such as an ethoxy group and a propoxy group. However, 2-aminoanisole-3-sulfonic acid, 2
-Aminoanisole-4-sulfonic acid, 2-aminoanisole-6-sulfonic acid, 3-aminoanisole-2-
Sulfonic acid, 3-aminoanisole-4-sulfonic acid,
3-aminoanisole-5-sulfonic acid is particularly preferably used.

The weight ratio of the (A) group monomer composed of aniline, N-alkylaniline and phenylenediamine used in the polymerization to the (B) group monomer composed of alkoxy-substituted aminobenzenesulfonic acids represented by aminoanisolesulfonic acids. Is A: B = 8: 2
１ ： 1: 9, preferably A: B = 7: 3 to 2: 8. The alkoxy group-substituted aminobenzenesulfonic acids represented by aminoanisolesulfonic acids may be used alone or in a mixture of isomers at an arbitrary ratio. Here, when the ratio of the alkoxy group-substituted aminobenzene sulfonic acids represented by aminoanisole sulfonic acids is small, the introduction ratio of the alkoxy group-substituted amino benzene sulfonic acids represented by aminoanisole sulfonic acids becomes low, and the solubility in the solvent becomes low. When the amount is large, the introduction ratio of the alkoxy-substituted aminobenzenesulfonic acid represented by aminoanisolesulfonic acid increases, and the conductivity tends to decrease.

The copolymerization can be carried out by oxidative polymerization with an oxidizing agent in a neutral or acidic solvent. The polymerization operation is preferably performed in a temperature range of -5 to 70C, more preferably in a range of 0 to 60C. Where-
Below 5 ° C., the solubility of the copolymer in the solvent tends to decrease, and above 70 ° C., the conductivity tends to decrease. Conventionally, it has been considered that the polymerization of polyanilines can proceed sufficiently only in an acidic solvent, but according to the method of the present invention, not necessarily an acidic solvent, but also in a neutral solvent such as water alone. It was found that the reaction proceeded sufficiently.

The solvent used for the reaction is water, methanol,
Ethanol, isopropanol, acetonitrile, methyl isobutyl ketone, dimethylformamide, dimethylacetamide and the like are preferably used.

As the oxidizing agent, ammonium peroxodisulfate, hydrogen peroxide or the like is used, and it is used in an amount of 0.1 to 5 mol, preferably 0.5 to 5 mol, per 1 mol of the monomer. As the acid, sulfuric acid, hydrochloric acid, p-toluenesulfonic acid or the like or a mixture thereof is used, and the concentration of the acid is 0.1 to
It is used in an amount of 3 mol / l, preferably in the range of 0.2 to 2 mol / l. At this time, it is also effective to add a transition metal such as iron or copper as a catalyst.

Here, the copolymer of aniline and / or N-alkylaniline with an alkoxy-substituted aminobenzenesulfonic acid has a sulfonic acid group introduction ratio of 25 to 40% with respect to the aromatic ring. The copolymer of phenylenediamines and alkoxy-substituted aminobenzenesulfonic acids has a sulfone group introduction ratio of 2 to the aromatic ring.
It is as high as 5 to 50% and tends to have good solubility. The molecular weight of the aniline-based conductive polymer having an alkoxy group and a sulfonic acid group on the same aromatic ring thus obtained is 300 to 5
00,000. Further, the content of the alkoxy group and the sulfonic acid group is 25 to 50% based on the whole aromatic ring. Further, without performing sulfonation operation, water or an organic solvent containing a base such as ammonia and an alkylamine or an organic solvent or a mixture thereof is used. Can be dissolved.

[0015]

Embodiments will be described below with reference to embodiments. Examples 1 to 10 At least one compound selected from aniline, N-alkylaniline and phenylenediamines and an alkoxy-substituted aminobenzenesulfonic acid were added to a solvent (Table 1).
2), and the solution of the oxidizing agent was added dropwise. After dropping,
After further stirring for a predetermined time, the reaction product was separated by filtration, washed and dried to obtain a copolymer powder (see Table 3). The physical properties of the obtained copolymer are as shown in Table 5. Comparative Examples 1-2 Aniline or phenylenediamines and aminobenzenesulfonic acids were added to an acidic solvent (see Tables 1-2), and an acidic solution of an oxidizing agent was added dropwise. After completion of the dropwise addition, the mixture was further stirred for a predetermined time, and then the reaction product was separated by filtration, washed, and dried to obtain a copolymer powder (see Table 4). The physical properties of the obtained copolymer are as shown in Table 6.

[0016]

[Table 1]

[0017]

[Table 2] <Abbreviation> PPDA: N-phenylphenylenediamine DPPDA: N, N'-diphenylphenylenediamine (n, m) AAS: n-aminoanisole-m-sulfonic acid AS: aminobenzenesulfonic acid

[0018]

[Table 3] APS: ammonium peroxodisulfate PTS: p-toluenesulfonic acid

[0019]

[Table 4]

[0020]

[Table 5]

[0021]

[Table 6]

[0022]

[Description of physical property measurement method]

(1) Surface resistance after film formation 1 g of the obtained product was added to a 0.1N ammonium solution 100
g. Thin film (200-500) on glass substrate
After forming A), the surface resistance of the film was measured. (2) Measurement method of sulfonation rate The sulfonation rate was determined by decomposing a sample in a combustion flask and measuring the sulfur content by an ion chromatography method. (3) Solubility The polymer was added little by little to 10 ml of an alkali solution containing ammonia at a concentration of 0.3 mol / liter in water or methanol.

[0023]

【effect】

(1) According to the present invention, a polymer having high conductivity can be obtained without the necessity of performing doping and without providing a sulfonation step. (2) The polymerization system of the present invention does not necessarily need to be performed in an acidic solution, but proceeds in a neutral solution. (3) Since the polymer of the present invention is water-soluble and soluble in organic solvents, it can be easily applied in the form of a solution, such as spraying and dipping, and can be used for antistatic, electronic circuits, capacitors, batteries, etc. Can be used for various applications. (4) Japanese Patent Application No. 3-36022 of the applicant's prior invention
6 shows properties similar to those of the polymer obtained by the invention of No. 6, but the polymer of the prior invention comprises aminobenzenesulfonic acid units as a constituent, whereas the present invention relates to aminoanisole used for the first time in this kind of polymer. The present invention has succeeded in providing a novel conductive polymer comprising an alkoxy group-substituted aminobenzenesulfonic acid unit represented by sulfonic acid as a constituent component.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C08G 73/00 CA (STN)

Claims (4)

(57) [Claims] 1. An at least one compound (A) selected from the group consisting of aniline, N-alkylaniline and phenylenediamines, and an alkoxy-substituted aminobenzenesulfonic acid (B), (A): (B) Weight ratio of 8:
A water-soluble and organic solvent-soluble aniline-based conductive polymer having a molecular weight of 300 to 500,000 obtained by copolymerization at a ratio of 2-1: 9. 2. The water-soluble and organic solvent-soluble aniline-based conductive polymer according to claim 1, wherein the content of the alkoxy group and the sulfonic acid group is 25 to 50 mol% based on the whole aromatic ring. 3. The water-soluble compound according to claim 1, which has a surface resistance of 5 × 10 ⁹ Ω / □ or less, a solubility in water of 20 mg / ml or more, and a solubility in alcohol of 5 mg / ml or more. Organic solvent soluble aniline conductive polymer. 4. A method according to claim 1, wherein at least one compound (A) selected from the group consisting of aniline, N-alkylaniline and phenylenediamines and an alkoxy-substituted aminobenzenesulfonic acid (B) are (A) :( B ) Is 8:
A method for producing a water-soluble and organic solvent-soluble aniline-based conductive polymer, which comprises copolymerizing with an oxidizing agent in a solution at a temperature of 5-2 to 1: 9 at a temperature of -5 to 70 ° C.