JPS61264053A - Production of electrically-conductive resin composite material - Google Patents

Abstract

PURPOSE:To produce a resin composite material which is moldable and has improved electrical conductivity, obtained by bringing a mixed gas of oxygen and a heterocyclic 5-membered compound to thermoplastic resin particles impreg nated with an oxidizing agent. CONSTITUTION:(A) Thermoplastic resin particles such as pellets, powder, beads, etc. of polyethylene, polypropylene, etc., and (B) an oxidizing agent consisting of an inorganic acid, metallic salt, etc., preferably a metallic chloride such as ferric chloride, etc., are ground together to give the particles A impregnated with the component B, which is put in a fluidized bed reactor, etc. A mixed gas of oxygen and (C) vapor of a heterocyclic 5-membered compound such as pyrrole, thiophene, etc., or a mixed gas obtained by diluting the gas with an inert gas is brought into contact with the particles by circulation of the gas, etc., so an electrically-conductive resin composite material having a ratio of the component C in the composite material to the component A of preferably 0.1-2 is produced.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing a conductive composite.

Specifically, the present invention relates to a method for producing a conductive resin composite comprising a thermoplastic resin and a five-membered heterocyclic compound polymer.

[Conventional technology]

It is already well known that five-membered heterocyclic compounds form insoluble and infusible polymers in the presence of oxidizing agents. for example,
Pyrrole and its derivatives are oxidized by inorganic acids, iron chloride, benzoquinone, ozone, etc. to form polymers such as pyrrole black and pyrrole red (Advances in
Heterocycbc Chemistry.

vo115, page 67, (1973)). Similar reactions also turn furan, thiophene, and their derivatives into polymers.

On the other hand, membrane-like polymers of furan, pyrrole, and thiophene can be obtained by electropolymerization in the presence of an appropriate electrolyte (for example, J, C, S, Chemical Commu.
nication, 1979.635 pages, J
apanJournal of Applied Ph
ysics vol 2] (1982) L562
pages, etc.).

Furthermore, an example of a method for obtaining a composite with other resins by electrolytic polymerization is described in 'Polymer Preprints J
APAN VO133 (1984), page 844.

[Problems to be solved by the invention]

In the above-mentioned conventional methods, the polymer obtained by the oxidizing agent is insoluble and infusible, and it is difficult to mold it into a desired shape. Further, electrolytic polymerization can only yield a film-like polymer in a specific form, and requires expensive electrolytes and equipment.

As a result of intensive research into ways to solve these problems, the inventors of the present invention found that by using a specific polymerization method to create a composite resin of a thermoplastic resin and a five-membered heterocyclic compound polymer, it was possible to create a composite resin that is moldable and conductive. They discovered that a resin composite with good properties could be obtained, and completed the present invention.

[Means for solving problems]

That is, the present invention is a method for producing a conductive resin composite, characterized in that thermoplastic resin particles impregnated with an oxidizing agent are brought into contact with a gas containing oxygen and a five-membered heterocyclic compound.

As the oxidizing agent used in the present invention, inorganic acids and metal salts are effective, including inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, and chlorosulfonic acid, aluminum known as Lewis acid,
Specific examples include metal compounds such as chlorides, sulfates, nitrates, and acetylacetonate compounds of tin, titanium, zirconium, chromium, manganese, iron, copper, molybdenum, tungsten, luranium, palladium, platinum, etc.
Organic compounds such as benzoquinone and diazonium salts can also be used. Among them, metal chlorides can be preferably used.

Thermoplastic resins used in the present invention include polyethylene, polypropylene, polyvinyl chloride, polystyrene, styrene-acrylonitrile copolymer, polycarbonate, polyester, polyisoprene, ethylene-
Commercially available propylene rubber can be used, as long as it is in a shape suitable for contacting the five-membered heterocyclic compound after being impregnated with an oxidizing agent.
・It can be in any shape such as powder, beads, etc.)

In the present invention, the resin particles are impregnated with the oxidizing agent described above, but there are no particular restrictions on the impregnation method. Usually, a solution of an oxidizing agent dissolved in a solvent,
This is carried out by dispersing the above thermoplastic resin particles. As preferable conditions, a solvent that easily permeates into the thermoplastic resin can be used.

In addition, in the case of crystalline thermoplastic resin, select a solvent that dissolves the resin at high temperature, and form a homogeneous solution with the oxidizing agent at high temperature.
After cooling, the solidified resin containing the oxidizing agent can be separated by filtration or the like to obtain a thermoplastic resin impregnated with the oxidizing agent. Alternatively, thermoplastic resin particles impregnated with an oxidizing agent can also be obtained by dispersing the thermoplastic resin in a solution of the oxidizing agent and then filtering or distilling off the solvent.

Alternatively, the oxidizing agent and the thermoplastic resin may be co-pulverized, or the thermoplastic resin and the oxidizing agent may be mixed together using a solvent that dissolves both, and then precipitated and separated in a poor solvent for both. Alternatively, thermoplastic resin particles impregnated with an oxidizing agent can be obtained. There is no particular restriction on the ratio of the oxidizing agent to be impregnated into the thermoplastic resin, but the ratio by weight is preferably about 0.01 to 0.5.

Examples of the five-membered heterocyclic compound used in the present invention include pyrrole, furan, thiophene, selenophene, tellurophene, and derivatives thereof.

A mixed gas of the vapor of these compounds and oxygen, or a mixed gas further diluted with an inert gas, is brought into contact with the thermoplastic resin impregnated with the above-mentioned oxidizing agent to form a conductive resin composite. This contacting treatment is carried out under conditions substantially free of liquid media. That is, a method in which thermoplastic resin particles impregnated with the above-mentioned oxidizing agent are placed in a suitable container and a gas containing a five-membered heterocyclic compound and oxygen is caused to flow therein, or a fluidized bed type or fixed bed type reactor is used. There is a method in which thermoplastic resin particles impregnated with the above-mentioned oxidizing agent are placed in a container, and a gas containing a five-membered heterocyclic compound and oxygen is passed therethrough for contact treatment. In particular, as a method for uniformly carrying out the contact treatment, it is preferable to use a fluidized bed reactor.

There is no particular restriction on the reaction temperature, and the reaction proceeds satisfactorily even at room temperature. There is no particular restriction on the reaction time, but in order to obtain good conductivity, the polymer of the 5-membered heterocyclic compound should be added to the thermoplastic resin at a weight ratio of about 0.1 to 2 in the composite. It is desirable to flow the mixed gas so that it is contained.

The conductive composite resin obtained by the above method is subjected to an operation to remove the oxidizing agent if necessary, but when a Lewis acid is used as the oxidizing agent, it has the effect of improving conductivity as a dopant. No special removal of oxidizing agents was performed,
Simply removing the unreacted five-membered heterocyclic compound is sufficient.

[Effect]

By carrying out the method of the present invention, a moldable composite in which a relatively large amount of a five-membered heterocyclic compound polymer is uniformly dispersed can be obtained, and although the mechanism is unknown, the conductivity of the composite is significantly increased by oxygen. Therefore, it is presumed that a highly conductive resin composite can be easily obtained.

〔Effect of the invention〕

By carrying out the method of the present invention, a moldable conductive resin composite can be easily obtained and is of high industrial value.

〔Example〕

Hereinafter, the present invention will be further explained with reference to Examples.

Example 1 A glass tube was filled with 1.09 g of an oxidizing agent-impregnated resin obtained by co-pulverizing 1 part by weight of ferric chloride and 4 parts by weight of polypropylene, and 1 ml of pyrrole was mixed with dry air (20 ml/m
in). The reaction temperature is room temperature;
The time required was 24 hours. After drying, the weight of the obtained polypyrrole composite was 1.2 g, and the specific resistance of the heated and compressed molded product was 1.6 x 102 Acrn.

Comparative Example 1 The same operation as in Example 1 was performed except that nitrogen gas was used instead of dry air in Example 1, and the obtained polypyrrole composite had a 1.15. ? The specific resistance of the heated and compressed molded product was 16×10 3 fLσ.

Example 2 The same operation as in Example 1 was performed except that oxygen was used instead of the dry air in Example 1. The polypyrrole composite obtained was 1.211, and the molded product was heated and compressed. The specific resistance of is 7. OX was 10 Acm.

Example 3 The same operation as in Example 1 was performed except that the acrylonitrile copolymer "Balenox" (trademark, manufactured by Sohio Chemical Co., Ltd.) was used instead of polypropylene in Example 1, and the polypyrrole composite was The weight was 1.25 g, and the specific resistance of the heated and compressed molded product was s, oxto3.

Example 4 The same procedure as in Example 1 was performed except that pyrrole was replaced with thiophene and the reaction time was changed to 240 hours. The polythiophene complex obtained was 1.1 g.
The specific resistance of the heated and compressed molded product is 4.5 x 1
It was 05.7'T-return.

Claims (1)

[Claims] 1. A method for producing a conductive resin composite, which comprises contacting thermoplastic resin particles impregnated with an oxidizing agent with a gas containing oxygen and a five-membered heterocyclic compound.