JPH04268375A - Polyamide composite - Google Patents

Abstract

PURPOSE:To provide a conductive polyaniline composite which is moldable into any desired shape, is excellent in mechanical strengths and flexibility or in the resistance to abrasion, heat, and solvent, and can be mass-produced industrially. CONSTITUTION:A water-sol. conductive polyaniline composite is prepd. by oxidatively polymerizing aniline or a deriv. thereof in the presence of a water- sol. acrylic monomer.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to polyaniline composites, and more particularly to electrode materials for plastic batteries;
Capacitors, electromagnetic shielding materials, electrostatic adsorption films,
The present invention relates to polyaniline composites useful in conductive paste materials, antistatic materials, display elements, electronic devices, etc.

0002

2. Description of the Related Art Conventionally, conductive polyaniline doped with a dopant has been proposed to be used in the form of an electrolytically polymerized thin film, film or sheet for various purposes such as electrode materials. For example, JP-A-59-981
No. 56 and JP-A-62-164730 describe improving the properties of polyaniline by doping with polymer anions. As methods for producing polyaniline molded bodies for use in such applications, methods using chemical polymerization methods, methods using electrolytic oxidation polymerization methods, etc. are known.

According to a method using a chemical polymerization method, polyaniline is synthesized by adding aniline to an aqueous solution of hydrochloric acid and adding thereto an oxidizing agent such as ammonium persulfate. Polyaniline obtained by chemical polymerization is sparingly soluble or insoluble in water and organic solvents, and by dedoping with an alkaline solution such as aqueous ammonia, N-methyl-2-pyrrolidone (N
It becomes soluble in organic solvents such as MP). A self-supporting polyaniline film with a thickness of 5 to 100 μm can be obtained from this NMP solution, but the film formed is insulating and requires doping with protonic acid to impart conductivity. It is. (For example, “Polym
er Preprints, Japan, 38(7)
, 2139, (1989)). In addition, the polyaniline film formed by this method has poor mechanical strength,
Once formed, it becomes insoluble and has poor processability.
Another problem is that it is easily influenced by the environment. Furthermore, depending on the type of substituent on the aromatic ring, it may not be possible to form a film.

On the other hand, in a method using electrolytic oxidation polymerization, aniline is dissolved in an aqueous electrolyte solution, an electrode is immersed therein as an anode, and a voltage is applied to deposit polyaniline on the electrode. Although this method yields a film-like polymer with excellent properties such as conductivity, it is more expensive to produce than chemical polymerization methods and is not suitable for mass production. In addition, when the amount of electricity is small, a thin film is formed, but when the amount of electricity is large, a precipitate in the form of agglomerated powder is formed and falls off the electrode, making it difficult to obtain a thick film. There's a problem.

[0005] In order to improve the above-mentioned problems, a polyaniline composite has been proposed in which a meltable thermoplastic synthetic resin is used as a binder and polyaniline powder is dispersed therein (Japanese Patent Laid-Open No. 64-69662). This polyaniline composite shows improvement in mechanical strength, but depending on the grinding conditions of polyaniline, the dispersion state of polyaniline particles becomes uneven, which tends to cause uneven conductivity.
It has poor solvent resistance, heat resistance, abrasion resistance, and poor electrical conductivity, so it is necessary to improve the electrical conductivity, and to do so, it is necessary to use a material doped with a large amount of polyaniline. have.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems in the prior art. That is, the object of the present invention is to provide a conductive polyaniline composite that can be molded into any shape, has excellent mechanical strength and flexibility, or has excellent abrasion resistance, heat resistance, and solvent resistance, and can be industrially mass-produced. It's about providing things.

[0007]

[Means for Solving the Problems] As a result of study, the present inventors have discovered that a water-soluble and conductive polyaniline composite exhibiting excellent properties when a water-soluble acrylic monomer is coexisting during oxidative polymerization of aniline or its derivatives. They discovered that a product can be obtained and completed the present invention. The polyaniline composite of the present invention is a water-soluble and conductive polyaniline composite containing polyaniline, and is formed by oxidative polymerization of aniline or a derivative thereof in the presence of a water-soluble acrylic monomer.

The polyaniline composite of the present invention is obtained in the form of a composite of polyaniline and a water-soluble acrylic monomer polymer. It is composed of monomer units represented by I). (In the formula, R1 to R5 may be the same or different and each represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an alkoxy group.)

Specific examples of aniline derivatives constituting the monomer unit represented by the above general formula (I) include 2-methoxyaniline, 3-methoxyaniline, 2,3-dimethoxyaniline, and 2,5-dimethoxyaniline. , 3,5-dimethoxyaniline, 2,6-dimethoxyaniline, 2-
Ethoxyaniline, 2-ethoxy-3-methoxyaniline, 3-ethoxyaniline, 2,3-diethoxyaniline, 2,5-diethoxyaniline, 3,5-diethoxyaniline, 2,6-diethoxyaniline, 2 -methoxy-3-ethoxyaniline, 2-ethoxy-5-methoxyaniline, 2,3,5-trimethoxyaniline,
2,3,6-trimethoxyaniline, 2,3,5,6-
Tetramethoxyaniline, 2,3,5,6-tetraethoxyaniline, 2,3-dimethylaniline, 2-methyl-3-methoxyaniline, 2,3,5,6-tetramethylaniline, 2-methyl-5- methoxyaniline,
Examples include 2,5-dimethylaniline, etc.
It is not necessarily limited to these.

In the present invention, water-soluble acrylic monomers used in conjunction with the oxidative polymerization of aniline or aniline derivatives include acrylamide, acrylic acid, itaconic acid, maleic acid, vinyl acetate, methacrylic acid, and 2-hydroxy. Ethyl methacrylic acid, 2-hydroxyethyl acrylic acid, N-vinylpyrrolidone, N-methylol acrylamide, naphthylene bisacrylamide,
Examples include styrene sulfonic acid and vinyl sulfonic acid, but are not necessarily limited to these.

[0011] In the oxidative polymerization of aniline or aniline derivative, it is preferable to use the water-soluble acrylic monomer and aniline or aniline derivative in a ratio in the range of 1:40 to 10:1, but there are no particular limitations. isn't it. As the reaction medium, water or a water-miscible organic solvent such as THF or methanol is used, and the oxidative polymerization can be carried out in an oxidizing solution containing an oxidizing agent and a protonic acid in the reaction medium. That is, it can be carried out by incorporating aniline or an aniline derivative and a water-soluble acrylic monomer into the above-mentioned oxidizing solution, and stirring the mixture at room temperature for several hours. As the oxidizing agent, ammonium persulfate, ferric chloride, etc. can be used, and as the protonic acid, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, perchloric acid, tetrafluoroboric acid, hexafluorophosphoric acid, etc. can be used. can.

The formed reaction mixture containing the polyaniline composite may be formed into a film by casting or coating it on a substrate, either as it is or in a concentrated form. However, when the formed polyaniline complex is to be isolated from the reaction mixture, the reaction mixture may be poured into an organic solvent such as alcohol or acetone, and the precipitated polyaniline complex may be filtered off. Furthermore, in the case of purification, the obtained polyaniline complex may be dissolved in water and then reprecipitated using an organic solvent.

The polyaniline composite of the present invention can be used as molded articles in various forms depending on the purpose of use. For example, surface coating is performed by applying, spraying, dipping, etc. on the surface of various solids such as metals, semiconductors, synthetic resins, ceramics, paper, and fibers with an aqueous solution of a polyaniline composite, and then the organic solvent is removed. Accordingly, a conductive article having a conductive film formed on the solid surface can be manufactured. In addition, an aqueous solution of polyaniline complex,
It can be cast batchwise or continuously and dried to form a conductive film of desired thickness. Furthermore, conductive fibers or film-like materials can also be formed by extruding an aqueous solution of the polyaniline composite through a die. Ru.

[0014]

[Examples] The present invention will be described in detail by examples below.
The present invention is not limited to these. Example 1 Add 10 ml of 12N hydrochloric acid to 200 ml of water, add aniline 4
．． 65g and 6.5g of 2-hydroxyethyl methacrylic acid
g was dissolved. 11.4g of ammonium persulfate to 1 part of water
An oxidizing agent solution dissolved in 0.00 ml was prepared. These two solutions were cooled to 5° C. with ice water, then mixed and stirred for several hours. After concentrating the obtained black-green solution using a rotary evaporator, the concentrated solution was applied onto a Teflon substrate.
The coated product was dried at 80° C. to remove moisture, and an oxidized aniline polymer film was obtained. This film has hygroscopic properties, and even if it is once dried, it will absorb moisture if left in the air.
It was found to be soluble in water. When the conductivity of a film with a thickness of 80 μm was examined using the 4-probe method, it was found to be 2.
．． It was 2×104 S/cm.

Example 2 Polymerization was carried out in the same manner as in Example 1, except that 5.6 g of acrylamide was used in place of the 2-hydroxyethyl methacrylic acid used in Example 1, and 3.7 g of aniline was used. A black-green reaction solution was obtained. This reaction solution was concentrated using a rotary evaporator and reprecipitated in ethanol. 100 parts by weight of water was added to 5 parts by weight of the obtained polyaniline composite to prepare a mixed solution, and a film was obtained in the same manner as in Example 1. The conductivity of the film with a thickness of 60 μm was 3.4×10 5 S/cm.

Example 3 Polymerization was carried out in exactly the same manner as in Example 1, except that 2-propylaniline was used in place of the aniline used in Example 1. The obtained reaction solution was concentrated and applied onto a Teflon substrate to obtain a film. The conductivity of the film with a thickness of 77 μm was 4.3×10 5 S/cm.

[0017]

[Effects of the Invention] Since the polyaniline composite of the present invention has the above-mentioned structure, it is electrically conductive and water-soluble. Furthermore, since polyaniline is in a composite form with a polymer formed by polymerizing a water-soluble acrylic monomer, it has superior mechanical strength, flexibility, and moldability compared to a self-supporting film made only of polyaniline. Moreover, since it is water-soluble, it is possible to easily obtain films, sheets, and other arbitrary shapes using an aqueous solution, and industrial mass production is possible. Furthermore, since it is conductive, it can be applied to a wide variety of fields, such as electrode materials for plastic batteries, capacitors, electromagnetic shielding materials, electrostatic adsorption sheets, conductive paste materials, and display elements.

Claims (1)

[Claims] 1. A polyaniline-containing water-soluble conductive polyaniline composite formed by oxidative polymerization of aniline or its derivative in the presence of a water-soluble acrylic monomer.