JPH0348934B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing an electrically 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 when treated with oxidizing agents. For example, Advances in Heterocyclic Chemistry
Cyclic Chemistry) Vol. 15, p. 67 (1973) shows that pyrrole is oxidized by inorganic acids, iron chloride, benzoquinone, and ozone to form polymers such as pyrrole black and pyrrole red;
Polymers of thiophene derivatives can also be obtained by the same reaction. On the other hand, it is also known that film-like polymers of furan, thiophene, and pyrrole can be obtained by electrolytic polymerization in the presence of an appropriate electrolyte. For example, J.C.
S.Chemical Communication 1979 635 pages,
Japan Journal of Applied Physics vol 21
Examples can be found in L562 (1982) and vol23 L527 (1984). Furthermore, a method to obtain composites with other resins by electropolymerization is available at Polymer Preprints Japan.
vol 33 (1984) page 844.

[Problem that the invention seeks to solve]

In the above conventional methods, there is a problem in that the method using an oxidizing agent cannot produce a conductive molded product in the desired shape that is insoluble and infusible, and the electrolytic polymerization method requires expensive electrolytes and equipment. Moreover, there is a problem in that only certain shapes can be obtained.

As a result of intensive studies by the present inventors on methods for solving the above problems, the above problems can be solved by manufacturing a composite of a thermoplastic resin and a 5-membered heterocyclic compound using a specific method. They discovered that a resin composite can be obtained and completed the present invention.

[Means for solving problems]

That is, the present invention involves dispersing thermoplastic resin particles impregnated with an oxidizing agent in a solvent in which a five-membered heterocyclic compound is dissolved and which does not substantially dissolve the oxidizing agent and the thermoplastic resin particles while introducing oxygen. This is a method for producing a conductive resin composite characterized by mixing.

Inorganic acids and metal salts are effective as oxidizing agents used in the present invention, including inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, and chlorosulfonic acid, as well as aluminum, tin, titanium, zirconium, chromium, and manganese known as Lewis acids. Specific examples include metal compounds such as chlorides, sulfates, nitrates, and acetylacetonate compounds such as iron, copper, molybdenum, tungsten, luranium, palladium, and platinum, and organic compounds such as benzoquinone and diazonium salts can also be used. It is. 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,
Commercially available rubber such as polyisoprene or ethylene-propylene rubber can be used, as long as it is in a shape that facilitates dispersion and mixing when it comes into contact with the five-membered heterocyclic compound after being impregnated with the oxidizing agent. It may be in any shape such as pellets, powder, beads, etc.

In the present invention, there are no particular restrictions on the method of impregnating the thermoplastic resin with the oxidizing agent, but for example, the oxidizing agent and the thermoplastic resin are mixed in a solvent that dissolves the oxidizing agent but not the thermoplastic resin, and then filtration. Alternatively, examples include a method of removing the solvent by evaporation, a method of dissolving both and then condensing and precipitating in a solvent that does not dissolve both, or a method of co-pulverizing both using a pulverizer or the like. The amount of oxidizing agent used relative to the thermoplastic resin is generally 0.01 to 0.5 weight ratio.

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

Among them, pyrrole and its derivatives are preferred because of their high reaction rate.

In the present invention, the contact between the thermoplastic resin impregnated with an oxidizing agent and the five-membered heterocyclic compound is carried out in a solution that dissolves the five-membered heterocyclic compound but does not substantially dissolve the oxidizing agent or the thermoplastic resin. This is done by dispersing and mixing. This allows the reaction to occur uniformly and quickly. Although the solvent used varies depending on the combination, saturated hydrocarbon compounds are preferred in many cases because they hardly dissolve the oxidizing agent.

There are no particular restrictions on the contact temperature and contact time, but for example, it is common to carry out the reaction at room temperature for 5 to 200 hours, and the reaction amount is 0.05 to 2 of the 5-membered heterocyclic compound relative to the thermoplastic resin. Generally, the reaction is carried out until the weight specific polymerization is achieved. After the contact reaction, the composite is separated by filtration or the like, dried if necessary, and then thermoformed to form a molded product with a desired structure.

What is important in the present invention is that the reaction of the five-membered heterocyclic compound is carried out while introducing oxygen, and as the oxygen source, air can also be used in addition to pure oxygen. As for the introduction method, it is convenient to introduce it into a solvent using a nozzle, but the reaction may also be carried out under pressure of oxygen using a pressure-resistant container.

[Effect]

By carrying out the method of the present invention, it is possible to form a composite in which a comparatively large amount of a five-membered heterocyclic compound polymer is uniformly dispersed, and by conducting the reaction while introducing oxygen, the reason is that Although unknown, the conductivity of the molded product is significantly improved.

〔Effect of the invention〕

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

〔Example〕

The present invention will be further explained below with reference to Examples.

Example 1 1 part by weight of ferric chloride and polypropylene (135°C
Intrinsic viscosity measured with tetralin solution: 1.88) 2.0 g of oxidizing agent-impregnated resin obtained by co-pulverizing 4 parts by weight of n-
It was dispersed in a solution of 2 ml of pyrrole dissolved in 30 ml of hexane, and reacted for 2 hours while introducing air into the solution at a rate of 20 ml/sec. The obtained polypyrrole composite was washed with cyclohexane and dried.

The yield was 2.2g. The specific resistance of the molded product obtained by heating and compressing the composite powder is 1.9×
It was 10 ² Ω・cm.

Comparative Example 1 The reaction was carried out in the same manner as in Example 1 except that nitrogen was introduced instead of air. Yield is 2.2g
However, the specific resistance of the molded product was 9.6×
10 ³ Ω·cm, which was inferior to Example 1.

Example 2 In Example 1, 10 ml of oxygen was used instead of air.
The reaction was carried out in the same manner as in Example 1 except that sec. The yield remained unchanged at 2.2g, and the specific resistance of the molded product was 1.6.
×10 ² Ω·cm, which was good.

Example 3 In Example 1, polycarbonate (manufactured by Teijin Kasei Ltd., Panlite L-1250) was used instead of polypropylene.
(trade name)) was used, but the reaction was carried out in the same manner as in Example 1. The yield is 2.2g, and the specific resistance of the molded product is 2.6×
It was 10 ³ Ω・cm.

Comparative Example 2 The reaction was carried out in the same manner as in Example 3, except that nitrogen was introduced instead of air. Yield is 2.2g
The specific resistance of the molded product was 5.8×10 ⁴ Ω·cm, which was inferior to that of Example 3.

Example 4 Polypropylene powder was mixed with a solution of titanium trichloride in methanol, and the methanol was evaporated to remove 1 part by weight of polypropylene.
Polypropylene impregnated with 0.1 part by weight of oxidizing agent was obtained. The reaction was carried out in the same manner as in Example 1 except that this oxidizing agent-impregnated polypropylene was used. The yield was 2.1 g, and the specific resistance of the molded product was 8.5×10 ³ Ω·cm.

Claims (1)

[Claims] 1. Thermoplastic resin particles impregnated with an oxidizing agent are dispersed and mixed in a solvent in which a five-membered heterocyclic compound is dissolved and which does not substantially dissolve the oxidizing agent and the thermoplastic resin particles while introducing oxygen. A method for producing a conductive resin composite.