JPH0518205B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a conductive sheet composition. Specifically, the present invention relates to a method for producing an electrically conductive sheet-like composition by uniformly dispersing and polymerizing a five-membered heterocyclic compound in a polymer or prepolymer dissolved in a solvent, and then removing the solvent.

[Conventional technology]

It has long been known that pyrrole, thiophene, and furan can be turned into insoluble and infusible polymers by oxidizing agents. For example, the polymerization of pyrrole by oxidizing agents such as inorganic acids, iron chloride, benzoquinone, and ozone has been shown in Advances in Heterocylic Chemistry.
Ckmistry) Volume 15, Page 67 (1973). In addition, it has recently been reported that film-like polypyrrole, polythiophene, and polyfuran are produced by electrolytic polymerization, as reported by AFDiaz et al., JCS Chemical Communication 1979.
Page 635, K. Kaneto et al. Japan. Journal of
Applied Physics Volume 21 (1982) L562.T.Ohsawa
and others. They are shown in Japan Journal of Applied Physics Volume 23 (1984) L527. on the other hand,
Niwa et al. have reported that a composite with other polymers can be produced by electrolytic polymerization (Polymer
Preprints Japan Volume 33 (1984) 844).

[Problem to be solved by the invention]

The conductivity of polypyrrole, polythiophene, and polyfuran can be greatly improved by doping them with an appropriate dopant, but the polymers obtained with oxidizing agents are insoluble and infusible, and cannot be shaped into the desired shape. The method for obtaining the above-mentioned polymer or composite by electrolytic polymerization requires the following steps in order to obtain a large-area product:
There are problems in that the manufacturing cost is high as it requires electrodes with a large area, and it is extremely difficult to obtain a conductive composite with a thick film because the polymer is obtained by electrolytic polymerization.

The present inventors have conducted intensive studies on a method for obtaining a conductive sheet-like composition having a desired thickness and a desired area, which solves the above-mentioned problems, and have completed the present invention.

[Means to solve problems]

That is, the present invention comprises a liquid in which a polymer or prepolymer and a five-membered heterocyclic compound are dissolved (liquid A), and a liquid in which an oxidizing agent is dissolved in a solvent that is not substantially dissolved and mixed with the solution (liquid B). This is a method for producing a conductive sheet-like composition, which is characterized in that the solvent is removed by evaporation after the liquid A is brought into contact with the liquid in a substantially non-flowing state.

The polymer or prepolymer used in the present invention is not particularly limited as long as it has a solvent that dissolves it, and known polymers can be used. Polyethylene, polypropylene, ethylene-propylene copolymer, polyvinyl chloride, polystyrene, styrene-acrylonitrile copolymer, polyvinyl acetate, polybutadiene,
Addition polymers such as polyisoprene, polycondensates such as polycarbonate, polyester, polyamide, polyimide precursors, and polyurethane can also be used.

Examples of the five-membered heterocyclic compound include pyrrole, thiophene, furan, and derivatives thereof. Among them, pyrrole and its derivatives are preferred because they have a high reaction rate and the resulting sheet composition has high conductivity.

The weight ratio of the five-membered heterocyclic compound to the polymer or prepolymer is not particularly limited, but it is generally used at a weight ratio of about 0.01 to 0.5.

Further, the concentration of the polymer or prepolymer in the A liquid is usually 1 to 50 g/100 ml.

The solvent to be used is not particularly limited as long as it can dissolve the polymer or prepolymer and the five-membered heterocyclic compound.

Inorganic acids and metal compounds are effective as oxidizing agents used in the present invention, including inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, and chlorosulfonic acid; aluminum, tin, titanium, zirconium, chromium, manganese, which are known as Lewis acids; Specific examples include metal compounds such as chlorides, sulfates, nitrates, and acetylacetonate compounds of iron, copper, molybdenum, tungsten, ruthenium, palladium, and platinum. Organic compounds such as benzoquinone and diazonium salts can also be used. These oxidizing agents may be used alone or in combination of two or more.

The above-mentioned solvent for dissolving the oxidizing agent may be one that does not substantially mix with the solvent used to dissolve the polymer or prepolymer, but even if the solvent alone dissolves and mixes with the solvent,
If a solvent that does not dissolve the polymer or prepolymer is used as a solvent for the oxidizing agent, the A liquid and the B liquid can be brought into contact with each other without substantially mixing. There is no particular limit to the concentration of the oxidizing agent, but it is common to use 0.1wt% or more.
Hetero5-membered cyclic compound 1 in liquid A when the liquids are in contact with each other
It is preferable that the amount of the oxidizing agent in liquid B be about 1 mol to 1/1000 mol.

The method for contacting both liquids is to place liquid B in a container of the desired size to make a thin liquid surface, and then gently heat liquid A to a thickness that will form a sheet with the desired thickness after the solvent is evaporated and removed. Alternatively, liquid A, which has a relatively high polymer concentration and does not substantially flow at low temperatures, is formed into a sheet and introduced into liquid B, which is kept at a low temperature to a desired thickness, for a specified period of time. Examples include a method in which the solvent is removed by evaporation from a sheet-like molded product taken out from liquid B, but the important thing is that when liquids A and B are brought into contact, at least liquid A is substantially fluid. This is to allow the reaction to occur without allowing the reaction to occur.

〔Effect of the invention〕

By carrying out the method of the present invention, the hetero5-membered cyclic compound polymer is produced in the polymer or prepolymer with good dispersion, and moreover, it is highly concentrated on the surface of the obtained sheet composition, so that it has good conductivity. A sheet-like composition is obtained.

〔Example〕

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

Example 1 A solution in which 5 g of ethylene-propylene rubber (manufactured by Mitsui Petrochemical Co., Ltd., Tafmer 0680 (trade name)) and 0.5 ml of pyrrole were dissolved in 100 ml of toluene (liquid A)
On the other hand, prepare a solution (solution B) by dissolving 2 g of ferric chloride in 100 ml of water and separating the insoluble matter. Add 4 ml of ferric chloride solution (liquid B) to a shear plate (approximately 30 cm ² area)
Then, gently add 4ml of liquid A and leave it as it is.
It was kept at room temperature for 10 hours. Then at 40℃ in a nitrogen stream
After drying for 1 hour, the ethylene-propylene rubber layer was taken out and dried on a Teflon sheet at 60°C under reduced pressure to obtain an ethylene-propylene rubber sheet (thickness: about 0.1 mm).

When the specific resistance of the sheet obtained by the four-probe method was measured, it was 1.4×10 ¹ Ω·cm. Furthermore, the amount of polymerized pyrrole measured from the weight of the sheet was 6% by weight relative to ethylene propylene rubber.

Example 2 As liquid A, 5 g of polycarbonate (trade name manufactured by Teijin Kasei Ltd.) was added to 100 ml of ethylene dichloride.
The same procedure as in Example 1 was carried out except that a solution containing Panlite L-1250) and 0.5 ml of pyrrole was used, and solution A was first added to the shear dish, followed by solution B.

The specific resistance of the obtained sheet was 8.5×10 ² Ω·cm. Furthermore, the weight measurement revealed that the polymerized amount of polypyrrole was 5% by weight relative to the polycarbonate.

Example 3 The same process as in Example 2 was carried out except that polyvinyl chloride (manufactured by Mitsui Toatsu Chemical Co., Ltd., trade name: Vinicron 4000M) was used instead of polycarbonate. The specific resistance of the obtained sheet was 1.3×10 ² Ω·cm. The polymerized amount of polypyrrole determined by weight measurement was 7% by weight relative to polyvinyl chloride.

Example 4 The oxidation example and the other Example 3 using K ₂ S ₂ O ₈ were treated. The amount of polymerized polypyrrole is 3wt% relative to polyvinyl chloride, and the specific resistance of the obtained sheet is
It was 6.3 to 10 ³ Ω·cm.

Claims (1)

[Claims] 1 A liquid in which a polymer or prepolymer and a five-membered heterocyclic compound are dissolved (liquid A) and a liquid in which an oxidizing agent is dissolved in a solvent that is not substantially dissolved and mixed with the solution (liquid B).
A method for producing a conductive sheet-like composition, which comprises bringing the liquid A into contact with the liquid A in a state where the liquid A does not substantially flow, and then evaporating the solvent.