JPS6164729A - Production of aniline polymer - Google Patents

Abstract

PURPOSE:To obtain an aniline polymer suitable as, e.g., a high electric conductivity sheet material at a low cost without the need of dehydration, by polymerizing an aniline compound in the presence of an oxidizing agent in an anhydrous condition. CONSTITUTION:The purpose aniline polymer is obtained by polymerizing an aniline compound such as aniline, N-methylaniline, o-chloroaniline or m- methoxyaniline in the presence of an oxidizing agent in an anhydrous condition. The oxidizing agent is generally used in an amount of, preferably 3-1/3mol per mol of the aniline compound. In order to perform the polymerization uniformly, a suitable solvent (e.g., absolute alcohol) may be used. The obtained aniline polymer can be rendered highly electroconductive by, for example, iodine doping.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an aniline polymer, which comprises polymerizing an aniline compound in a substantially anhydrous state in the presence of an oxidizing agent.

Conductive polymers are highly patented materials that have the lightness and processability of polymeric compounds and the electrical conductivity of metals. However, conductive polymers are generally sensitive to oxygen and have many practical problems. In an effort to overcome this drawback, several types of conductive polymers have been proposed, and measurements have actually been made for various applications. However, a film with high conductivity can only be obtained by electrolytic polymerization, which is a unique polymerization method, for electro9 polymers that are difficult to react with oxygen, and therefore the manufacturing cost is high. On the other hand, polyaniline has attracted attention because it maintains considerable electrical conductivity even when it is doped into a sheet-like product formed from powder obtained by a common polymerization method, and is stable in air. However, since current polyanilines are obtained using catalysts that function in the presence of water, it is necessary to dehydrate the resulting polymer. Generally, it is difficult to dehydrate an amine compound such as aniline, so it has the drawback of high purification cost. As a result of searching for a catalyst system that polymerizes even in an anhydrous state, the present inventors discovered that polymerization can be carried out even in an anhydrous state by using a certain oxidizing agent, and were able to arrive at the present invention.

The aniline compound in the present invention refers to a compound represented by general formula (1). T.

[Here, R1 to R8 are hydrogen, halogen, a saturated hydrocarbon group having 5 or less carbon atoms, or an alkoxy group having 5 or less carbon atoms, and at least one of R1 to R5 is a hydrogen atom. ] Typical examples include aniline, N-methylaniline, O-chloroaniline, m-chloroaniline, p-
Chloraniline, O-methoxyaniline, m-methoxyaniline, p-methoxyaniline, 0-ethoxyaniline, m-ethoxyaniline, p-ethoxyaniline, O
-Methylaniline, m-methylaniline, and p-methylaniline.

Representative examples of the oxidizing agent in the present invention include aluminum trichloride, zinc chloride, tin chloride, copper chloride, iron trichloride, and the like. The oxidizing agent varies depending on the polymerization performance of the aniline compound, but is generally preferably between 3 times the mole and 1/3 mole of the aniline compound. Further, in order to uniformly carry out the polymerization, an appropriate solvent (for example, known solvents such as anhydrous alcohols and ketones) may be used.

The polymerization method in the present invention only requires bringing the aniline compound into contact with an oxidizing agent while stirring. Polymerization c quality is -8
24 hours or less is sufficient for r:ff1 total ff between 0°C and 120°C. In order to increase the polymerization yield, an inert gas atmosphere is preferable in the polymerization system. Generally, the produced polymer is washed and purified by a known method to remove impurities before use.

The polyaniline polymer obtained in this way can be made highly conductive by known doping, is stable even in the air, and has low manufacturing costs, so it can be used industrially (i.e.
lIillII is high.

The present invention will be described in more detail with reference to Examples below.

Example 1 A mixture of 0.24 mol of aniline and 20 In1 of acetone was added dropwise to a solution of 0.12 mol of iron trichloride dissolved in 100 Id of acetone at room temperature and polymerized at 70° C. for 8 hours.

After polymerization, the mixture was separated, the oxidizing agent and aniline used were thoroughly washed with acetone, and then dried under reduced pressure. The conductivity due to iodine doping was 10 S/clR, and the infrared spectrum showed that undoped polyaniline was not oxidized even if it was left in air for 40 hours.

Examples 2 to 6 A C aniline polymer was obtained by carrying out a car chassis in the same manner as in Example 1, except that the aniline compound shown in Table 1 was used instead of aniline in Example 1, and it was similarly doped and evaluated. .

Examples 7 to 9 Polyaniline was obtained in the same manner as in Example 1 except that the oxidizing agent shown in Table 2 was used instead of iron trichloride in Example 1, and was doped and evaluated.

The above results are shown in Tables 1 and 2.

(Margins below) Table 1 Table 2 * Oxidation was determined using infrared spectroscopy.

Claims (1)

[Claims] A method for producing an aniline polymer, which comprises polymerizing an aniline compound in the presence of an oxidizing agent.