JPH0668018B2 - Method for manufacturing conductive material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a method for producing a conductive material. The conductive material obtained by the present invention has good conductivity without deteriorating the properties inherent to conventional materials, and can be made conductive by a simple method, so that it can be used in a wide range of application fields of conductive materials. It is a thing.

<Prior Art> In recent years, research on conductive polymers in which the polymer itself has conductivity has been conducted, and attention has been paid to polyacetylene, polyparaphenylene, polyphenylene sulfide, polythiophene, polypyrrole, and the like, and a wide range of conductive fields has been studied. ing. However, when considering the application of conductive polymers,
Material stability and moldability become major problems. First, regarding the stability, when exposed to air, the polyacetylene film reacts with oxygen and becomes brittle. Other polymers are relatively stable in the undoped state, but polymers doped with impurities are unstable in air. The only exception is polypyrrole, which is stable in films doped with impurities. It is known that pyrrole produces an insoluble and infusible polymer by an oxidizing agent. For example, pyrrole can be polymerized in an aqueous solution under the action of potassium persulfate, and the polymer is precipitated in the form of a fine black powder. Journal of Polymer Science 20 , 1089-
1095 (1982). There is also a method in which pyrrole is dissolved in an appropriate electrolytic solution and a polymer of pyrrole is obtained on the electrode by electrolytic oxidation polymerization (for example, Chemical Communication, page 635, (1979)).

However, these stably obtained polymers of pyrrole are insoluble and infusible powders or lumps, and cannot be formed into desired shapes by conventional methods. Further, in electrolytic polymerization, although a specific film-shaped product can be obtained, there is a problem in that it cannot be formed into a desired shape and requires expensive equipment.

<Problems to be Solved by the Invention> In view of such a situation, the present invention provides a simple method for improving the molding processability of a conductive polymer, which has been a drawback in the past, and producing a material having good conductivity. The purpose is to provide.

<Means for Solving Problems> In the present invention, in a specific organic solvent, even if FeCl ₃ .6H ₂ O, which is a pyrrole polymerization catalyst, is present, pyrrole polymerization hardly progresses, and a pyrrole polymer is also precipitated. A homogeneous mixed solution is obtained, and by further removing the organic solvent from this mixed solution, pyrrole is polymerized for the first time,
It is characterized by having the following requirements.

That is, a cyclic ether containing a pyrrole and / or a pyrrole derivative and a polymerization catalyst is attached to a substrate and dried to form a conductive polymer on the surface and / or inside of the substrate. And a method for producing a conductive material.

The compound used in the present invention is pyrrole, N-alkylpyrrole, N-arylpyrrole, or pyrrole substituted with a monoalkyl or dihalogen at a carbon atom. Usually, pyrrole is most preferably used.

A cyclic ether is effectively used as the organic solvent.
Examples of the cyclic ether include tetrahydrofuran and dioxane. These organic solvents can also be used as a mixture. Further, it may be mixed with a solvent other than the cyclic ether as long as the effect of the present patent is not impaired.

The pyrrole polymerization catalyst used in the present invention is mainly FeCl
Chlorides such as ₃ , FeCl ₃ .6H ₂ O and CuCl ₂ .2H ₂ O are effective.

In the present invention, a specific organic solvent and a polymerization catalyst and pyrrole are mixed, but the mixing method is not particularly limited,
It suffices to simply add pyrrole into a solution prepared by dissolving the polymerization catalyst in an organic solvent, and stir and mix as necessary. The treatment temperature and time are not particularly limited, and it is usually sufficient to perform the mixing treatment at room temperature for 1 minute to 10 hours.

The amount of the polymerization catalyst used is 0.
It is suitable to use 2 to 5 mol. If the amount of the polymerization catalyst is less than 0.2 mol, the pyrrole polymerization will not proceed sufficiently. Further, 5 mol is sufficient to polymerize the whole amount of pyrrole.

The amount of the organic solvent may be within the range in which the polymerization catalyst can be dissolved. The thus-obtained mixture of the specific organic solvent, the polymerization catalyst, and the pyrrole is applied or dipped to adhere to the substrate, and then dried to remove the organic solvent. Alternatively, polypyrrole is generated inside.

As the base material used in the present invention, various synthetic polymers, natural polymers, inorganic materials and the like are used. Any material that can be applied or dipped can be used. For example, phenol resin, urea resin, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin, thermosetting resin such as silicone resin, vinyl chloride resin, polyethylene resin, polypropylene resin, styrene resin, methacrylic resin, polyamide resin, etc. Thermoplastic resin, cellulose, starch, natural polymers such as natural rubber, polymer compounds such as inorganic polymers such as glass, silica and alumina, and inorganic materials such as metals and ceramics, and cotton, hemp, silk, Fibers and cloths made of wool, rayon, cupra, acetate, vinylon, nylon, vinylidene, vinyl chloride fiber, acrylic fiber, polyester fiber, fine paper, art paper, coated paper, kraft paper, glassine paper, Japanese paper, cardboard paper, Paper such as filter paper is also effective.

The method of attaching the pyrrole liquid is not particularly limited, but a method of immersing the base material in the mixed liquid, a method of casting the mixed liquid on the base material,
All commonly used adhesion methods such as surface coating with a coater and spray coating can be used.

The drying method for removing the organic solvent is also not particularly limited, and naturally drying is usually sufficient, but if the organic solvent is difficult to volatilize, drying under reduced pressure or raising the drying temperature is effective. Is. If the adhesion between the substrate and the coating is poor, adding a polymer compound that is soluble in the mixture to the mixture will improve the bond between the coating and the substrate and improve the adhesion. it can.

<Examples> Hereinafter, specific examples will be described. The conductivity in the examples was measured by the four-point probe method.

Example-1 Tetrahydrofuran 20m in a beaker with a capacity of 50m
Add 4g of FeCl ₃ · 6H ₂ O and add 1g of pyrrole.
Was added and stirred for 30 minutes. The mixture was a dark yellow transparent homogeneous solution. A polyvinyl chloride film was dipped in this mixed solution and wetted uniformly. The color of the film at this time did not show the black color peculiar to polypyrrole and did not polymerize,
As it was, the mixture was allowed to stand for 3 to 5 minutes, and as the tetrahydrofuran was volatilized and dried, pyrrole was polymerized on the film surface, and a composite film with polyvinyl chloride was produced. The color tone of the obtained film was black, and the generation state of the polymer was uniform. The conductivity of the film is 10 ^-2 S /
It was cm.

Example-2 A conductive material was prepared in the same manner as in Example-1, except that cotton cloth, polyester nonwoven cloth, nylon cloth, and fine paper were used as the substrate.

Table I shows the color tone of the obtained conductive material, the generation state of the polymer, and the conductivity.

Example-3 The same operation as in Example-1, except that dioxane was used in place of tetrahydrofuran and a nylon cloth was used as a base material, the conductive cloth had a black color tone and a uniform polymer production state. there were. The conductivity of the film is 10 ^-1 S / cm
Met.

Example-4 It operated like Example-3, but t-butanol was used instead of dioxane. The color tone of the conductive cloth was black and the formation of the polymer was uniform. The conductivity of the film was 10 ^-3 S / cm.

Example-5 The operation was performed in the same manner as in Example-1, except that the polyvinyl chloride film was coated with an applicator to a polypyrrole film thickness of 10 μm instead of the dipping method. The color tone of the obtained conductive film was black, and the generation state of the polymer was uniform. The conductivity of the film is 10 ^-2 S / cm.
Met.

Example-6 The procedure of Example-1 was repeated, except that 20 m of methanol was added to the mixed solution. The color tone of the obtained conductive film was black, and the generation state of the polymer was uniform. The conductivity of the film was 10 ^-3 S / cm.

Comparative example-1 It operated like Example-1, but acetone was used instead of tetrahydrofuran. The mixture was reddish brown. The color tone of the obtained conductive film was reddish brown, and the generation state of the polymer was uniform. The conductivity of the film is 1
It was 0 ^-7 S / cm.

Same procedure as Comparative Example -2 Example -1, except that FeCl ₃ · 6H ₂ O 40
g was used. FeCl ₃ .6H ₂ O was not completely dissolved, and when 1 g of pyrrole was added, a large amount of black lumps were produced.

<Effects of the Invention> As described above, by carrying out the method of the present invention,
It is possible to manufacture a conductive material that can be molded by a simple method, and in particular, it is possible to impart conductivity to a molded body having a complicated shape, which is extremely valuable industrially.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 61-197636 (JP, A) JP 61-157522 (JP, A) JP 61-235428 (JP, A) JP 62- 37133 (JP, A)

Claims (2)

[Claims] 1. A cyclic ether containing pyrrole and / or a pyrrole derivative and a polymerization catalyst is attached to a substrate,
A method for producing a conductive material, which comprises forming a conductive polymer on the surface and / or inside of a substrate by drying. 2. The method for producing a conductive material according to claim 1, wherein the cyclic ethers are tetrahydrofuran and dioxane.