JPS63136419A - Manufacture of compound conducting film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing a conductive film, and more specifically, the present invention relates to a method for producing a conductive film, and more specifically, by using the organic solvent used to react and produce a conductive polymer as a resin solvent, fine particles can be formed. The present invention relates to a method for producing a composite conductive film in which a conductive polymer is uniformly dispersed.

[Conventional technology]

Electrically insulating polymers are made conductive by kneading metal powders such as gold and silver and conductive fillers such as graphite and carbon black into synthetic resin, or by mixing them with a resin face and forming a film as a solution. BACKGROUND ART Composite conductive films are well known, and are widely used for electrode/circuit materials, antistatic applications, and the like. In addition, by contacting a heterocyclic compound such as pyrrole in the gas phase with a polymer film containing a polymerization catalyst such as an oxidizing agent, polypyrrole is generated on the surface and inside of the resin, resulting in a film with high conductivity. It is also known that (Unexamined Japanese Patent Publication No. 6
(Refer to Publication No. 1-157522) Furthermore, it is known that conductive polypyrrole can be produced on the surface and inside of the resin by coating polyvinyl chloride etc. on the electrode and electrolytically oxidizing and polymerizing a pyrrole solution containing an electrolyte. There is. (Unexamined Japanese Patent Publication 1986
(Refer to Publication No. 105532) [Problems to be solved by the invention] However, in the conventional conductive filler composite type conductive film, there is a problem that it is difficult to make the conductive filler fine and uniformly disperse it in the resin. However, there were drawbacks such as the fact that the film thickness could not be made very thin. Even in the case of composite systems using one molecule of conductive polymer, gas phase polymerization requires large, closed equipment to make the film conductive, and there are other problems such as the reaction taking too long. In the electrolytic polymerization method, because the reaction is initially carried out through an electrically insulating film, it is difficult to obtain a very thick film, and because the film is peeled off from the electrode after the reaction, very thin films cannot be used due to mechanical strength. There are drawbacks.

The present invention was made in view of the above circumstances, and its main purpose is to use an organic solvent, which serves as a reaction site for a conductive polymer responsible for conductivity, as a solvent for subsequently dissolving and dispersing a resin. At the same time, the formation reaction of the conductive polymer occurs in seconds to minutes, and the reaction polymer is uniformly dispersed in the dissolved and dispersed resin before it precipitates and aggregates. The object of the present invention is to provide a manufacturing method that allows a conductive film to be obtained either in the form of a continuous film or in the form of a pattern.

[Means for solving problems]

That is, in the present invention, a solution of an oxidative polymerization catalyst, which itself acts as a dopant, dissolved in an organic solvent is stirred at a temperature below O''CC, and a monomer that polymerizes to develop conductivity is added to the oxidative polymerization catalyst. After adding and introducing the conductive polymer at a molar ratio of 1.0 or less to produce a conductive polymer, the solution is stirred at room temperature or above and below the boiling point of the organic solvent to increase its solubility in the organic solvent. A conductive polymer dispersed resin solution is prepared by adding and mixing a resin having a film-forming ability.Then, after coating or casting the solution on a substrate, drying and removing the organic solvent to form a film, The problem was solved by further washing the film to remove unreacted oxidative polymerization catalyst.

The polymer responsible for conductivity in the present invention is preferably one that is stable in a conductive state (oxidation/polymerization state) and must be capable of electroless polymerization. As the monomer that exhibits conductivity through polymerization, one or more compounds of a heterocyclic compound such as pyrrole, its S'A 4 form, aniline, or an aniline derivative are suitable.

Heterocyclic compounds include pyrrole and substituted pyrroles, such as N-alkylpyrroles, N-arylpyrroles, monoalkylpyrroles substituted in the 3-position and monohalogenated pyrroles, dialkylpyrroles substituted in the 3- and 4-positions. and dihalogenated pyrroles, thiophenes, substituted thiophenes, such as monoalkylthiophenes and monohalogenated thiophenes substituted in the 3-position, dialkylanilines and dihalogenated thiophenes substituted in the 3- and 4-positions, anilines and derivatives thereof, such as , N-alkylaniline, N-dialkylaniline, halogenated aniline, dihalogenated aniline, halogenated-N-alkylaniline, halogenated-N-dialkylaniline, dihalogenated-N-acetylaniline, phenylenediamine and substituted products thereof Examples include certain N-alkylphenylenediamines, N,N'-dialkylphenylenediamines, and N,N''-dialkylphenylenediamines, and one or more of the above compounds may be used in combination.

The polymerization catalyst itself acts as a dopant after the reaction, and includes ferric chloride, cupric chloride, molybdenum chloride,
Metal salts such as ruthenium chloride, metal oxides such as lead dioxide, beroxo salts such as potassium persulfate and ammonium persulfate, quinones such as benzoquinone, diazonium salts such as henzhendiazonyram chloride, potassium ferricyanide, hexachloroplatinum (IV) Examples include acids, but ferric chloride, particularly anhydrous ferric chloride, is most desirable because of its solubility in organic solvents that serve as reaction sites and solvents for dissolving the resin, and the resulting electrical conductivity.

As the organic solvent used in the present invention, diethyl ether, acetonitrile, ethyl acetate, and nitromethane are preferable, and those that can be used although the solubility of the catalyst is low include xylene, benzene, hexane, carbon tetrachloride, and tetrahydrofuran. Note that water may be mixed with these organic solvents within a range not exceeding 10%, but in the present invention, using water itself as a solvent means that a reaction at a temperature below O''CC is adopted, and finally This is not preferred from the viewpoint of physical properties such as water resistance of the resin, which determines the physical properties of the resulting film.

The electroconductive polymer dispersed in the resin undergoes an electroless solution reaction in an organic solvent, but the reaction is quick and complete within several seconds to several minutes. The electrical conductivity of the resulting polymer varies depending on the type of polymerization catalyst used as a dopant and the type of organic solvent, but in order to create a more regular molecular structure and a long conjugated system, in order to prevent side reactions, It is necessary to carry out the reaction at a lower temperature, and since this polymerization reaction is an exothermic reaction, it is desirable to carry out the reaction at a lower temperature of 0°C or lower.

A conductive polymer is produced by introducing the above-mentioned monomers as a solution or gas into an organic solvent solution in which a polymerization catalyst has been dissolved in advance, but in the case of a seven-mer rich polymer, the reaction rate is slow and it is difficult to obtain a polymer. The electrical conductivity will also be low, and the more catalyst to dopant there is, the faster the reaction will be, and the higher the obtained electrical conductivity will be. However, even if the molar ratio of monomer/dopant is increased to 171 or more, the electrical conductivity will not be as high. Doesn't improve. That is, in the present invention, the monomer is added/introduced in a molar ratio of 1.0 or less to the oxidative polymerization catalyst. Note that even if 10 moles or more of catalyst is used per mole of monomer, the reaction will proceed in the same way, but when it is later combined with resin, a large amount of unreacted catalyst will remain in the film. Therefore, the addition ratio is preferably 1:1 to 5:1.

The produced polymer is fine particles with a size of 0.5 μ or less, but usually has a specific gravity of more than 1. In order to avoid precipitation and agglomeration and to improve reaction efficiency, in the present invention, during the above steps,
It is important to continue stirring.

Next, in the step of adding a resin to the organic solvent dispersion containing the conductive polymer, the entire solution is first heated to above room temperature, and a resin having film-forming ability that has been previously dissolved in the same solvent is added. By mixing and stirring, a resin solution is obtained in which the conductive polymer is uniformly dispersed. There is no particular restriction on adding additives such as silica or a coupling agent to this solution in order to adjust the viscosity of the solution or improve the physical properties of the obtained film.

The resin used in the resin solution is not particularly limited as long as it has solubility in the organic solvent and film-forming ability, and examples include polyester, polyamide, polyvinyl chloride, polyvinyl acetate, butyral, and salt. Bee vinegar type,
Various resins can be used alone or in combination depending on the purpose of the final acrylic yarn ring film. Further, if necessary, a curing agent such as an isocyanate may be used in combination for crosslinking.

After coating or casting the obtained resin solution onto a base material such as a synthetic resin film or metal foil using a known method, the organic solvent is dried and removed to form a film, and if necessary, the film is removed from the base material. A composite conductive film is produced by removing the unreacted oxidation polymerization catalyst remaining on the film surface by washing the film after peeling or as it is with a solvent such as water or alcohol that dissolves the catalyst but does not dissolve the resin. It was done.

[For production]

In the present invention, the conductive polymer is produced in an organic solvent in a short time, and the produced conductive polymer is dispersed in Ia? Since the resin is directly added to and mixed with the medium, the steps of separation, removal, and re-addition and mixing are omitted, and the conductive polymer particles are uniformly mixed with the resin without agglomeration or precipitation while still being generated. Therefore, it is possible to produce an excellent composite conductive film with excellent dispersion line of the conductive polymer in the resin and stable conductivity when formed into a film.

〔Example〕

Anhydrous ferric chloride FeCff1z16 as an oxidative polymerization catalyst
．． 2 g (0.1 mol) was dissolved in 300 ml of a solvent of ethyl acetate/diethyl ether = 9/1. The container used is a glass container with a stirring device. 15 minutes of this solution
While stirring and maintaining the mixture at °C, 5 ml (0.07 mol) of pyrrole (CaHsN) was added as a 7-mer to react. The reaction occurs immediately after the addition of virol,
The solution turned brownish in color. After continuing stirring at -5°C for 10 minutes, the entire container was heated to 30°C, and 4% of a 25% solution of linear polyester resin dissolved in ethyl acetate was added to it.
00 ml was added and further stirred for 20 minutes to obtain a slightly dark brown resin solution.

This resin solution was gravure coated on a biaxially stretched polyester film (thickness 25μ) using a 150f-60μ gravure plate, and the solvent was removed by drying to obtain a single-sided conductive film. The thickness of the coated composite conductive film layer is 2
, 4μ.

This composite film was immersed in a methanol/water = 3/7 solvent, washed, and then dried to finally obtain a composite conductive film. The physical properties are described below.

Conductivity ~ Surface resistance value 3.2
/15an surface-A19μ/PET '''μm80°C
-15ec 1.13kg/15mm *The conductivity of the polymer before resin addition is 7Ω-1cm as a pressed powder.
-1.

〔Effect of the invention〕

As explained in detail above, according to the present invention, a composite conductive film having a wide range of physical properties can be obtained very easily.

Furthermore, according to the present invention, a resin solution containing a conductive polymer can be easily obtained using a reaction vessel, etc., which has conventionally been widely used in the chemical industry, and by controlling the resin concentration and liquid viscosity, roll coating, gravure coating, screen printing,
Not only can a composite conductive film be obtained by various methods such as blade coating, but also a film in which fine particles of conductive polymer are uniformly dispersed, which has been difficult to obtain with carbon black and the like, can be obtained. As a result, there is little deterioration in the strength of the film, and by changing the ratio of resin and polymer, a composite conductive film with light transmittance can be obtained, and the commercial advantages are extremely large.

Claims (1)

[Claims] (1) After dissolving the oxidative polymerization catalyst, which itself acts as a dopant, in an organic solvent, while stirring the solution at a low temperature of 0°C or lower, add a monomer that polymerizes and develops conductivity.
After adding and introducing a conductive polymer at a molar ratio of 1.0 or less to the oxidative polymerization catalyst, the organic solvent is added while stirring the solution at room temperature or above and below the boiling point of the organic solvent. A conductive polymer dispersed resin solution is prepared by adding and mixing a resin that has solubility and film-forming ability. After coating or casting the solution on a substrate, the organic solvent is dried and removed to form a film. 1. A method for producing a composite conductive film, which comprises the steps of: