JP2860810B2 - Method for producing composite conductive material and composite conductive material obtained by this method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel method for producing a composite conductive material and a composite conductive material obtained by the method. More specifically, the present invention provides a composite conductive material having good conductivity and mechanical properties, on the surface of which a coating of a conductive polymer containing no unreacted polymerizable monomer or oxidizing agent is uniformly provided. The present invention relates to an efficient and cost-effective method for manufacturing, and a composite conductive material having the above-mentioned characteristics obtained by the method.

[Related Art] In recent years, with the technical progress of the electronics industry, development of materials for electronic components suitable for various purposes has become an urgent need. As one of them, conductive materials mainly composed of organic polymer materials have been attracting attention as wiring materials, electrode materials, sensors, and photoelectric conversion elements because of their excellent flexibility, workability, and chemical resistance. I have.

As such organic polymer conductive materials, conductive polymers such as polyacetylene, polypyrrole, polythiophene, and polyaniline are known as typical ones. Among these, polypyrrole, polythiophene, polyaniline and the like are usually obtained by oxidative polymerization of pyrrole, thiophene, aniline and the like in the presence of a chemical oxidizing agent.

However, the conductive polymer obtained by the conventional oxidative polymerization method is in a powder form, and is insoluble and infusible, and thus has a problem in workability and mechanical properties. Therefore, in order to solve such a problem, a composite method with a general-purpose polymer, specifically, a general-purpose polymer having a polymerizable monomer on the surface or inside is prepared by a method such as coating, impregnation, blending, and the like. A method of forming a conductive polymer on the back or inside of the general-purpose polymer by contacting with an oxidizing agent, or preparing a general-purpose polymer having an oxidizing agent and contacting the polymer with a polymerizable monomer to form a conductive polymer And the like. For example, a method of producing a conductive molded article by contacting a chemical oxidizing agent with a resin molded article containing a polymerizable monomer capable of forming a conductive polymer by chemical oxidation polymerization (Japanese Patent Application Laid-Open No. 61-123638), A conductive composite is produced by press-molding an insulating polymer to which pyrrole is applied or contained and an insulating polymer to which an oxidizing agent is applied or contained, such that the pyrrole is in contact with the oxidizing agent. A method (JP-A-62-37133) and the like have been proposed.

However, such a conventional method requires an excessive amount of a polymerizable monomer or an oxidizing agent, and the formed conductive polymer tends to contain an unreacted polymerizable monomer or an oxidizing agent. However, there are drawbacks in that it is difficult to obtain a composite conductive material having desired mechanical and electrical properties. Further, in the above method, when a composite conductive material is prepared by including a polymerizable monomer or an oxidizing agent in a resin material, a material that can be composited from the viewpoint of compatibility between the polymerizable monomer or the oxidizing agent and the resin material. Is inevitable to be restricted.

Such a problem is caused by coating a polymerizable monomer on the surface of a resin material, which is one of the above-described composite methods.
This can be solved to some extent by using a method of reacting an oxidizing agent, but in this case, the coating of the formed conductive polymer becomes non-uniform due to uneven application at the time of coating, or it is difficult to control the reaction. Therefore, problems such as accumulation of particulate products occur.

[Problems to be Solved by the Invention] The present invention overcomes the drawbacks of the conventional method for producing a composite conductive material, does not require an excessive polymerizable monomer or an oxidizing agent, and has an unreacted polymerization. A highly conductive and economical composite conductive material with good conductivity and mechanical properties with a homogeneous conductive film containing no conductive monomer or oxidizing agent formed on the surface, without being affected by the type of the material. The purpose is to provide an advantage.

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, a film-like insulating material containing an organic low-molecular compound capable of forming a conductive polymer by chemical oxidative polymerization. By contacting the conductive resin molded body with a desired insulating molded body via an oxidizing agent, a uniform conductive film is formed on the surface of each molded body, and it has been found that the object can be achieved. The present invention has been completed based on the findings.

That is, the present invention provides an insulating molded article and a film-shaped insulating resin molded article containing an organic low-molecular compound capable of forming a conductive polymer by chemical oxidative polymerization via an oxidizing agent. After forming a conductive polymer film on the body surface, a method for producing a composite conductive material, comprising providing a conductive polymer film on the surface of each formed body by peeling off both formed bodies, and To provide a composite conductive material comprising an insulating molded article having a conductive polymer film on the surface and a film-shaped insulating resin molded article having a conductive polymer film on the surface obtained by the method. It is.

 Hereinafter, the present invention will be described in detail.

There is no particular limitation on the organic low-molecular compound capable of forming a conductive polymer by chemical oxidative polymerization used in the present invention, and conventionally known compounds, for example, heterocyclic compounds such as pyrrole, thiophene, furan, indole and derivatives thereof. Alternatively, aniline and a derivative thereof can be used. As the pyrrole derivative, for example, N-alkylpyrrole, N-arylpyrrole, 3-
Alkylpyrrole, 3-halogenopyrrole, 3,4-dialkylpyrrole, 3,4-dihalogenopyrrole, and the like are preferred. Further, as the thiophene derivative, for example, 3-alkylthiophene, 3,4-dialkylthiophene, 2,2′-bithiophene and the like are preferably exemplified.
Further, as the aniline derivative, for example, N-alkylaniline, N-arylaniline, N-dialkylaniline, o-, m-alkylaniline, o-, m-halogenoaniline, 2,3-, 2,5-, 2, Preferred are 6-, 3,5-dialkyl or dihalogenoaniline.

Examples of the alkyl group in these derivatives include a lower alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group and a butyl group, and examples of the aryl group include an unsubstituted or substituted phenyl group. As the halogen atom, for example, a chlorine atom is preferable. One kind of the organic low-molecular compound capable of forming the conductive polymer may be used alone, or two or more kinds may be used in combination.

In the present invention, these organic low-molecular compounds are used by being contained in a film-shaped insulating resin molded product. The material of the resin molded product has compatibility with the organic low-molecular compound and is used. There is no particular limitation as long as it is stable to the oxidizing agent. Examples of such a resin material include polyethylene, polypropylene, polystyrene, ABS resin, vinyl chloride resin, vinyl acetate resin, acrylic resin, polyacetal, polycarbonate, thermoplastic polyester, unsaturated polyester, fluororesin, phenol resin, melamine resin and the like. And their copolymers and polymer alloys can also be used.

Using these resins, a method for producing a film-shaped insulating resin molded article containing the organic low-molecular-weight compound is performed by a method that does not cause decomposition or evaporation of the contained organic low-molecular-weight compound by heating or the like. There is no particular limitation, and it is not particularly limited and can be appropriately selected depending on the type of the resin to be used. For example, a casting method using a solvent that dissolves both the resin and the organic low-molecular compound can be preferably used. .

In the present invention, the content of the organic low-molecular compound in the film-like insulating resin molded product is usually 100
It is selected in the range of 1 to 100 parts by weight, preferably 10 to 50 parts by weight, per part by weight. There is no particular limitation on the shape of the resin molded product, but the film thickness is in the range of 5 to 5000 μm, and a shape capable of uniformly contacting a desired insulating molded product to be brought into contact with the molded product via an oxidizing agent. Preferably, the conductive film can be patterned by providing irregularities on the surface.

In the present invention, the material of the desired insulating molded body to be brought into contact with the film-like insulating resin molded body containing the organic low-molecular weight compound through an oxidizing agent is eroded by the organic low-molecular weight compound or the oxidizing agent. Alternatively, any material that does not undergo a reaction or the like may be used, and there is no particular limitation. Such materials include, for example, polyethylene, polypropylene,
Resin materials such as polystyrene, ABS resin, vinyl chloride resin, vinyl acetate resin, acrylic resin, polyacetal, polycarbonate, thermoplastic polyester, unsaturated polyester, fluororesin, epoxy resin, phenolic resin, melamine resin, and their copolymers and polymer alloys Rubber materials such as natural rubber, butadiene rubber, butadiene rubber, isoprene rubber, acrylic rubber, nitrile rubber, fluorine rubber, silicone rubber, and urethane rubber; glass; and inorganic materials such as ceramics represented by yttrium oxide, lanthanum oxide, and silicon nitride. Is mentioned. The shape of the insulating molded body is not particularly limited, and any shape selected from a film shape, a sheet shape, a foam shape, a fiber shape, a rod shape and the like can be used.

The oxidizing agent used in the present invention is not particularly limited as long as its electrochemical equilibrium potential is higher than the oxidative polymerization starting potential of the organic low-molecular compound to be polymerized. Examples of such an oxidizing agent include metal salts such as ferric chloride and cupric sulfate, metal complexes such as potassium ferricyanide and hexachloroplatinic (IV) acid, peroxo acids such as potassium persulfate and ammonium persulfate, and benzoquinone. And diazonium salts such as benzenediazonium chloride. One of these oxidizing agents may be used, or two or more thereof may be used in combination.

In the present invention, the oxidizing agent is usually a suitable solvent,
For example, it is dissolved in an aqueous solvent such as water or alcohol and used in the form of a solution. The concentration of this solution varies depending on the oxidizing agent used, but is usually 0.01 to 1 mol / l, preferably 0.1 to 1 mol / l.
It is selected in the range of 0.5 mol / l.

In the present invention, the film-like insulating resin molded article containing the organic low-molecular compound and the desired insulating molded article are contacted via the oxidizing agent to polymerize the organic low-molecular compound. Thereby, a conductive polymer film is formed on the surface of each molded body. As a method of contacting both molded bodies via an oxidizing agent, for example, a method of immersing a film-shaped insulating resin molded body in an oxidizing agent solution and then contacting the same with a desired insulating molded body, After applying an oxidizing agent solution to the surface of the insulating resin molded body, a method of contacting the oxidizing agent solution with a desired insulating molded body can be used. The contact conditions may be such that the two compacts are in uniform contact, and the pressure at that time may be such that the oxidizing agent solution can exist between the two compacts. However, for example, when using an aqueous solution of a metal salt or the like as an oxidizing agent, by applying a pressure of about 5 to 10 g / cm ^{2 at} the time of the contact, a surface of about 0.5 to 1 μm A coating of conductive polymer is formed. Further, as the contact temperature, normal temperature is usually used.

In the present invention, after the conductive polymer film is formed on the surface of each molded body in this way, by peeling both molded bodies, a film-like insulating resin having a conductive polymer film on the surface is formed. A composite conductive material consisting of a molded body and a composite conductive material consisting of any insulating molded body having a coating of a conductive polymer on the surface are obtained at the same time.

The conductive polymer film formed on the surface of these composite conductive materials is usually a uniform thin film having a thickness of about 0.1 to 5 μm, and the conductive polymer film allows the material to have a good surface conductivity. Is given.

[Examples] Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

The surface resistance of the composite conductive material was measured by a four-terminal method.

Example 1 100 parts by weight of polymethyl methacrylate having a molecular weight of 100,000 and 50 parts by weight of pyrrole were mixed with dichloromethane at a solid concentration of 100 parts by weight.
After dissolving to a concentration of 30% by weight, this solution was coated on a polyester sheet with a bar coater and dried at room temperature for 24 hours. Then, the film was peeled off from the polyester sheet, and a 50 μm-thick pyrrole-containing polymethyl methacrylate I got a film.

Next, a 0.2 mol / l aqueous solution of ferric chloride was applied onto this film, and then a polyester film having a thickness of 100 μm was brought into contact with the film and kept at room temperature for 2 hours to carry out a polymerization reaction. Was peeled off.

As a result, the surface resistance of the polymethyl methacrylate film was 3.5 × 10 ⁴ Ω / □, and the surface resistance of the polyester film was 7.0 × 10 ³ Ω / □.

Example 2 Example 2 was carried out in the same manner as in Example 1, except that the polymerization time was changed to 6 hours and 24 hours.

As a result, the surface resistance of the polymethyl methacrylate film was 4.8 × 10 ³ Ω / □ (6 hours) and 2.2 × 10 ³ Ω / □.
(24 hours), polyester film surface resistance is 3.9 × 1
0 ³ Ω / □ (6 hours) and 2.1 × 10 ³ Ω / □ (24 hours).

Example 3 Example 3 was carried out in the same manner as in Example 1 except that a polyethylene sheet having a thickness of 200 µm was used instead of the polyester film.

As a result, the surface resistance of the polymethyl methacrylate film was 3.5 × 10 ⁴ Ω / □, and the surface resistance of the polyethylene sheet was 7.8 × 10 ³ Ω / □.

Example 4 Example 4 was carried out in the same manner as in Example 1 except that an ABS resin plate having a thickness of 3 mm was used instead of the polyester film.

As a result, the surface resistance of the polymethyl methacrylate film was 4.2 × 10 ⁵ Ω / □, and the surface resistance of the ABS resin plate was 8.6 × 10 5
It was ³ Ω / □.

Example 5 Example 5 was carried out in the same manner as in Example 1, except that a glass plate having a thickness of 5 mm was used instead of the polyester film.

As a result, the surface resistance of the polymethyl methacrylate film was 4.5 × 10 ⁴ Ω / □, and the surface resistance of the glass plate was 7.9 × 10 ³
Ω / □.

Example 6 Example 6 was carried out in the same manner as in Example 1 except that pyrrole was changed from 50 parts by weight to 30 parts by weight.

As a result, the surface resistance of the polymethyl methacrylate film was 3.1 × 10 ⁴ Ω / □, and the surface resistance of the polyester film was 2.8 × 10 ⁴ Ω / □.

Example 7 Example 7 was carried out in the same manner as in Example 1, except that a 0.2 mol / l aqueous solution of potassium persulfate was used instead of the 0.2 mol / l aqueous solution of ferric chloride.

As a result, the surface resistance of the polymethyl methacrylate film was 1.0 × 10 ⁹ Ω / □, and the surface resistance of the polyester film was 8.0 × 10 ⁸ Ω / □.

Example 8 Example 8 was carried out in the same manner as in Example 1 except that a 0.5 mol / l aqueous solution of ammonium persulfate was used instead of the 0.2 mol / l aqueous solution of ferric chloride.

As a result, the surface resistance of the polymethyl methacrylate film was 6.6 × 10 ⁶ Ω / □, and the surface resistance of the polyester film was 1.8 × 10 ⁴ Ω / □.

Example 9 Example 9 was carried out in the same manner as in Example 1, except that a 0.2 mol / l aqueous solution of potassium ferricyanide was used instead of the 0.2 mol / l aqueous solution of ferric chloride.

As a result, the surface resistance of the polymethyl methacrylate film was 3.6 × 10 ⁶ Ω / □, and the surface resistance of the polyester film was 5.8 × 10 ⁵ Ω / □.

Example 10 The same procedure as in Example 1 was repeated except that polyvinyl chloride was used instead of polymethyl methacrylate.
A pyrrole-containing polyvinyl chloride film having a thickness of 30 μm was prepared, and the procedure was carried out in the same manner as in Example 1 except that the pyrrole-containing polyvinyl chloride film was used instead of the pyrrole-containing polymethyl methacrylate film.

As a result, the surface resistance of the polyvinyl chloride film was 2.4
× 10 ⁵ Ω / □, polyester film surface resistance is 1.6 ×
It was 10 ⁵ Ω / □.

Example 11 In Example 1, an ABS resin was used in place of polymethyl methacrylate, and the thickness was 50 μm in the same manner as in Example 1.
Was prepared in the same manner as in Example 1 except that the pyrrole-containing ABS resin film was used instead of the pyrrole-containing polymethyl methacrylate film.

As a result, the surface resistance of the ABS resin film was 1.2 × 10 ⁵ Ω
/ □, the surface resistance of the polyester film is 4.8 × 10 ⁵ Ω /
It was □.

Example 12 The same procedure as in Example 3 was repeated except that polyvinyl acetate was used instead of polymethyl methacrylate.
A pyrrole-containing polyvinyl acetate film having a thickness of 80 μm was prepared, and the procedure was carried out in the same manner as in Example 3 except that the pyrrole-containing polyvinyl acetate film was used instead of the pyrrole-containing polymethyl methacrylate film.

As a result, the surface resistance of the polyvinyl acetate film was 7.5
× 10 ³ Ω / □, surface resistance of polyethylene sheet is 4.0 × 10
It was ³ Ω / □.

Example 13 A polycarbonate film having a thickness of 50 μm was prepared in the same manner as in Example 3 except that a polycarbonate was used instead of polymethyl methacrylate in Example 3, and the pyrrole-containing polycarbonate film was used instead of the pyrrole-containing polymethyl methacrylate film. It carried out similarly to Example 3 using the polycarbonate film.

As a result, the surface resistance of the polycarbonate film was 3.
6 × 10 ⁵ Ω / □, surface resistance of polyethylene sheet is 2.1 × 1
0 ⁵ Ω / □.

Example 14 Example 14 was carried out in the same manner as in Example 1, except that aniline was used instead of pyrrole and the polymerization time was changed to 6 hours.

As a result, the surface resistance of the polymethyl methacrylate film was 2.3 × 10 ¹⁰ Ω / □, and the surface resistance of the polyester film was 2.8 × 10 ¹⁰ Ω / □.

Example 15 Example 15 was repeated except that aniline was used in place of pyrrole and that 0.2 mol / l of potassium persulfate / 2 mol / l of sulfuric acid was used instead of 0.2 mol / l of ferric chloride. The procedure was performed in the same manner as in Example 1.

As a result, the surface resistance of the polymethyl methacrylate film was 4.9 × 10 ¹⁰ Ω / □, and the surface resistance of the polyester film was 4.2 × 10 ¹⁰ Ω / □.

Example 16 Example 16 was carried out in the same manner as in Example 1, except that N-methylaniline was used instead of pyrrole.

As a result, the surface resistance of the polymethyl methacrylate film was 4.2 × 10 ⁹ Ω / □, and the surface resistance of the polyester film was 1.6 × 10 ⁸ Ω / □.

Example 17 In Example 3, except that N-methylaniline was used instead of pyrrole and 0.2 mol / l aqueous solution of ammonium persulfate was used instead of 0.2 mol / l aqueous solution of ferric chloride,
It carried out similarly to Example 3.

As a result, the surface resistance of the polymethyl methacrylate film was 4.5 × 10 ⁷ Ω / □, and the surface resistance of the polyethylene sheet was 1.2 × 10 ⁸ Ω / □.

Comparative Example 1 A conductive polymethyl methacrylate film was prepared in the same manner as in Example 1, except that the polyester film was not used.
The surface resistance of this film was 1 × 10 ¹² Ω / □.

Comparative Example 2 A conductive polymethyl methacrylate film was produced in the same manner as in Example 2, except that the polyester film was not used.

The surface resistance of the film with a polymerization time of 6 hours is 2.1 × 10 ⁸ Ω /
□, film surface resistance 5.6 × 10 ⁴ Ω / 24 hours polymerization time
It was □.

[Effects of the Invention] According to the present invention, a composite in which the amount of a polymerizable monomer and an oxidizing agent can be reduced and a uniform conductive polymer film containing no unreacted polymerizable monomer or an oxidizing agent is formed on the surface. A conductive material can be easily obtained.

Further, according to the present invention, a composite conductive material having good surface conductivity composed of a film-shaped insulating resin molded article having a uniform conductive polymer film on the surface and a uniform conductive polymer film on the surface are provided. It is possible to simultaneously produce a composite conductive material having a desired surface conductivity and comprising a desired insulating molded body. In particular, since the latter composite conductive material can be made of a resin, a rubber-like elastic material, or an inorganic material such as glass or ceramics, the material has a high degree of freedom in selecting the material, and furthermore, the material's original mechanical properties and the like are high. It has excellent features such as good surface conductivity being imparted without being impaired.

As described above, according to the present invention, a composite conductive material having good surface conductivity can be produced efficiently and cost-effectively, and the technology of the present invention has extremely high industrial value.

Claims (3)

(57) [Claims] An insulative molded article and a film-shaped insulative resin molded article containing an organic low-molecular compound capable of forming a conductive polymer by chemical oxidation polymerization are brought into contact with each other via an oxidizing agent. A method for producing a composite conductive material, comprising: forming a conductive polymer film on the surface; and peeling off both the formed materials to form a conductive polymer film on the surface of each of the formed materials. 2. A composite conductive material comprising an insulative molded article having a conductive polymer film on the surface obtained by the method according to claim 1. 3. A composite conductive material comprising a film-shaped insulating resin molded article having a conductive polymer film on the surface obtained by the method according to claim 1.