JPH0743968B2 - Method for manufacturing conductive film - Google Patents

Description

TECHNICAL FIELD The present invention relates to a continuous method for producing a conductive film.
In particular, it relates to a method for continuously producing a conductive film using heterocyclic compounds.

[Prior art and its problems]

It has been well known for a long time that heterocyclic compounds are polymerized with an oxidizing agent to obtain an insoluble and infusible polymer. For example, the formation of polymers such as pyrrole black and pyrrole red from pyrrole due to inorganic acids, iron chloride, benzoquinone, hydrogen peroxide, etc. is considered to be the advantage of Advan cis in heterocyclic chemistry (Advances i
n Heterocyciic Chemistry, Vol. 15, p. 67 (1973).

Similarly, furan, thiophene, other heterocyclic compounds, or substituted derivative thereof are also polymers.

On the other hand, it is also known that a film-like polymer such as pyrrole, furan, or thiophene can be obtained by electrolytic polymerization in the presence of an appropriate organic electrolyte, and for example, Chemical Communication (Chemical Communication) page 635 ( 1979), Japan Journal of Applied Physics
Volume 21 (1982), Polymer Preprints Japan (Polymer Preprints Japan) 33 (1984) and many other reports.

Since all of these reports are electrolytic polymerization methods, it is difficult to increase the area of the film-shaped product (film).
Since the adhesion between the electrode substrate and the product is poor and only a thin film can be obtained, there are problems such as lack of mechanical strength and uniformity.

In order to solve these problems, it is being gradually improved from both aspects of the device and the method.

Recently, by contacting a polymer compound substrate containing a polymerization catalyst with a heterocyclic compound, the substrate surface, and
It is known that a conductive polymer is formed inside.
It is shown in the official gazette.

In the above-mentioned publication, neither a fixed method nor an apparatus for producing a conductive film is shown, and a polymer compound film containing a polymerization catalyst is continuously contacted with heterocyclic compounds. Development of both a manufacturing method and an apparatus for obtaining a conductive film with an arbitrary width by a continuous winding method is urgent.

[Problems to be solved]

A polymer film is formed on a polymer compound substrate containing a polymerization catalyst disclosed in the above-mentioned JP-A-61-157522, and the polymer film and the heterocyclic compound are continuously contacted to obtain a conductive film. It is thought that a polymer film will be obtained,
The equipment and method were insufficient.

In particular, in a series of continuous devices having a film forming process of a polymer resin containing a polymerization catalyst, a reaction process with a heterocyclic compound, and a post-treatment process such as drying, a large machine and a multi-step process are required. However, the obtained conductive film lacks stability and becomes an expensive conductive film.

Generally, as a method for forming a polymer film, a. Calendar method, b. Inflation method, c. T-type die method,
D. There is a solution casting method.

However, in all cases (1) to (3), a polymer resin is heated and melted to be softened, and a film is finally obtained through a film forming and cooling process.

At this time, in order to melt and soften the polymer resin by heating, there is a difference depending on the kind of each polymer resin, but it is necessary to make the temperature considerably higher than 100 ° C.

Therefore, even if a polymer resin containing a polymerization catalyst at such a high temperature is formed into a film by the methods I to C, the polymerization catalyst may be denatured or modified, and further decomposition or the like may occur. The activity is lost.

On the other hand, in this method, both the polymerization catalyst and the polymer resin are dissolved in a solvent at room temperature, the solvent is then dried and removed, and a film is formed, the activity of the polymerization catalyst is not lost, and the polymer is uniformly dispersed in the polymer resin. .

Therefore, the present invention uses the solution casting method (2) of the above-described film forming method, and completes the reaction with the heterocyclic compound at the same time as the film formation, thereby rapidly and continuously stabilizing the conductive film. It is an object of the present invention to provide a method for producing a conductive film obtained.

[Means for solving problems]

A polymer resin solution containing a polymerization catalyst is cast on the surface of a polymer film supplied in a wound state running on an endless belt or a drum, and at the same time the solvent is removed,
A method for producing a conductive film, wherein the polymer resin solution is swollen with a solvent and simultaneously reacting with a heterocyclic compound, wherein the steps are a supply / discharge port of the polymer film and a heterocyclic system. A method for producing a continuous conductive film, which is carried out in an enclosed oven except for a compound supply / exhaust port, and the heterocyclic compounds are supplied together with hot air into the oven for reaction.

First, the resin containing the polymerization catalyst cast from the hopper contains a large amount of solvent, and a drying step in an oven is required to form a complete film.

In this step, in order to carry out the reaction with the heterocyclic compounds at the same time, hot air containing the heterocyclic compounds is blown onto the resin containing the polymerization catalyst which has entered the oven, and the exhaust air is continuously discharged at the same time. By carrying out the above process, a polymer layer composed of a heterocyclic compound is formed on the surface of the polymer film and inside thereof, whereby a conductive film is obtained.

In the case where it is desired to impart further conductivity, the conductive film may be subjected to a reaction step with a heterocyclic compound in the next step, and optionally post-dried, and finally, Obtained as a continuous conductive film on a winding roll.

Here, FIGS. 1 and 2 are for casting a polymer resin solution containing a polymerization catalyst on the surface of a polymer film supplied in a wound state, and a conductive film having a two-layer structure is obtained. .

Examples of the polymer resin solution used in the present invention include polyvinyl alcohol, polyvinyl fluoride, cellulose acetate, soft polyvinyl chloride, hard polyvinyl chloride, polystyrene, and rubber hydrochloride.

As a polymerization catalyst, ferric chloride, cupric chloride, sulfuric acid second
There are metal salts such as copper, metal oxides such as lead dioxide, peroxo salts such as potassium persulfate, ammonium persulfate, and quinones such as benzoquinone, diazonium salts such as benzenediazonium chloride chloride, and also An inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid or chlorosulfonic acid may be used.

Heterocyclic compounds include pyrrole, thiophene, furan,
N-alkylpyrroles, N-arylpyrroles, monoalkylpyrroles substituted in the 3-position, monohalogenated pyrroles, dialkylpyrroles substituted in the 3- and 4-positions, and dihalogenated pyrroles, monosubstituted in the 3-position Alkylthiophene, monohalogenated thiophene, dialkylthiophene substituted at the 3- and 4-positions,
And a dihalogenated thiophene, a monoalkylfuran substituted at the 3-position, a monohalogenated furan, a dialkylfuran substituted at the 3- and 4-positions, and a dihalogenated furan, aniline, an aniline derivative as an N-alkylaniline, N One or more compounds selected from dialkylaniline, halogenated aniline, dihalogenated aniline, halogenated-N-alkylaniline, halogenated-N-dialkylaniline, dihalogenated-N-acetylaniline Anything can be used as long as it can be supplied in the oven with hot air.

As hot air, basically on an endless belt, or
In order to remove the solvent in the polymer resin cast on the drum, an appropriate air volume may be used at a temperature of room temperature or higher.

In addition, by passing through an oven, it is possible to dry and simultaneously form a polymer film and impart conductivity,
The post-treatment drying step is not necessary, but when another step is additionally provided, a reaction step with heterocyclic compounds is provided,
If necessary, a drying process may be provided as a post process.

[Action]

As described above, by performing the film formation process of the polymer film containing the polymerization catalyst and the reaction process of the polymer film and the heterocyclic compound in the same process, it is possible to shorten the process and downsize the machine. It becomes possible, as the production of the existing polymer film, using a film casting machine by the solution casting method, the heterocyclic compounds are supplied to the polymer film together with hot air in the drying step,
Further, by drying, a polymer conductive film having conductivity is stably obtained continuously.

(Example-1) Using ferric chloride hexahydrate (reagent, special grade, unpurified) as a polymerization catalyst, polyvinyl alcohol (GL-05 type, manufactured by Nippon Synthetic Chemical Industry, unpurified) as a polymer resin Was used to set the catalyst concentration (*) to 20 (wt%), and water was used as a solvent to prepare an aqueous polymer solution (c) containing a polymerization catalyst. At this time, the viscosity was 150 c.p. at 23 ° C.

As the heterocyclic compound, pyrrole (Croda, Japan, unpurified) was used and blown into the oven together with hot air.

The absolute amount of pyrrole at this time was unknown.

As shown in FIG. 1, the film is formed by a drying drum 4 rotating in the center, a hopper 1 on the outer periphery of the drying drum 4, hot air supply ports 8 and 8 containing heterocyclic compounds, discharge ports 9 and 9 and a base. This was performed using an apparatus having an oven 6 surrounded by an outer wall 11 having a material film supply / discharge port 10 and a drying section 7 for post-treatment of the oven 6.

The line speed for film formation was 5, 10, 20 m / min, and the film thickness was about 25 μm.

The surface resistance and light transmittance of the obtained film were measured. The results are shown in Table-1.

* Catalyst concentration (wt%) = (catalyst weight) / (catalyst weight + polymer resin weight) × 100 (Example-2) As in (Example-1), polyvinyl alcohol (GL-05 Type, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., ferric chloride hexahydrate (reagent, special grade) as a polymerization catalyst, pyrrole (manufactured by Croda Japan, unpurified) as a heterocyclic compound, and a catalyst concentration of 10 (wt. %) And the line speed was set to 5, 10, and 20 m / min.

The surface resistance and light transmittance measured in the same manner as in the example are shown in Table-
Shown in 1.

(Comparative Example) Using the same apparatus as in (Example-1), the catalyst concentration was 20 (wt%).
A film of a pre-formed film and a desiccant composed of a polyvinyl alcohol resin (the same as that used in the embodiment) set and contained in the above is supplied through the base film supply / discharge port 10 of FIG. 1 (at this time, the hopper 1 The resin solution was not poured from.)
Under the same conditions, the hot air containing pyrrole was blown up by a wind-up roll.

At this time, the line speed of the film was changed and the surface resistance and light transmittance were measured in the same manner as in Example 1, and the results are shown in Table 2.

Also, the line speed was reduced to a fraction of that of Example 1, and the same procedure was performed to measure the surface resistance and the light transmittance, and the results are shown in Table 2.

As can be seen from Comparative Examples 1 to 3, even if a polymer film containing a catalyst and dried in advance was brought into contact with pyrrole, the reaction was insufficient when the polymer film was flowed at the same line speed as in (Example-1). There is a marked difference in conductivity compared with the method of.

Also, it is understood that the film must be flown at an extremely low speed in order to obtain the same level of conductivity as in (Example-1). (Comparative Examples 4 to 6) (Example-3) As can be seen from the results of (Example-1) and (Example-2), the one having a line speed of 20 m / min has a large surface resistance. As shown in the figure, a conductive film was obtained through a reaction process with pyrrole in the process subsequent to the film forming process. The results are shown in Table-3.

[Effects] As described above, the present invention uses the existing film forming machine to form a film,
By blowing hot air containing pyrrole at the time of drying to form a film and form a film, a conductive film can be stably and continuously obtained.

As described above, since a conductive film having a high added value of conductivity can be continuously obtained, it can be manufactured at a low price and provides a continuous manufacturing method of a conductive film having an extremely commercial value. Is.

[Brief description of drawings]

1 and 2 are explanatory views of an embodiment of the method for producing a conductive film of the present invention.

Claims (3)

[Claims] 1. A polymer resin solution containing a polymerization catalyst is cast on the surface of a polymer film supplied in a wound state which runs on an endless belt or a drum to remove the solvent and at the same time, the polymer resin. A method for producing a conductive film in which a solution is swollen with a solvent and a reaction with a heterocyclic compound is carried out at the same time. A method for producing a continuous conductive film, which is carried out in an enclosed oven except for the outlet, and the heterocyclic compounds are supplied into the oven together with hot air for reaction. 2. The heterocyclic compound according to claim 1, which is one or more compounds selected from pyrrole, thiophene, furan, aniline, and their alkyl-substituted compounds and derivatives. The method for producing a conductive film of. 3. The polymer resin solution is one selected from soft polyvinyl chloride, hard polyvinyl chloride, polyvinyl alcohol, rubber hydrochloride, polyvinyl fluoride, and cellulose acetate. The method for producing a conductive film according to item 2.