TWI424447B - A conductive material with carbon nanotubes, a method for manufacturing the same, and an electric double layer capacitor with the same - Google Patents

Description

Conductive material using nano carbon tube, manufacturing method thereof, and electric double layer capacitor using the same

The present invention relates to a conductive material using a carbon nanotube and a method of manufacturing the same. The conductive material of the present invention can be applied, for example, as a polarization electrode, and the polarization electrode can be a main component of an electric double layer capacitor in which a large amount of electricity can be accumulated. Throughout the scope of application for patents and the entire specification, "nano carbon nanotubes" means a plurality of carbon nanotubes in the shape of a brush.

The carbon nanotube system is formed by forming a graphite sheet continuously formed of a six-membered ring composed of carbon atoms into a circular, very fine tube (tube)-like material having a pore diameter of usually 1 (one billionth of a nanometer). It is a material with a very large aspect ratio. Incarbon tubes are expected to be used in the industry as a new carbon material because of their unique properties such as chemical stability, high strength, and wide electrical properties.

As one of its applications, the application of a bipolar electrode is exemplified, and the bipolar electrode is a member of an electric double layer capacitor. The energy regeneration system using the electric double layer capacitor has a semi-permanent life, hardly contains a substance that increases the environmental burden, and has excellent transient charge and discharge characteristics. In recent years, the carbon dioxide emission limitation technology in the global environmental problem has become an important issue, and the above-mentioned regeneration system is being developed in order to accumulate and reuse electricity that is unnecessarily discharged.

The present inventors have proposed a carbon nanotube conductive material, a method for producing the same, and an electrode using the same, wherein the carbon nanotube conductive material is a carbon nanotube that is first grown on a substrate, and is electrically conductive. The film or the conductive adhesive layer is formed by being transferred in a direction substantially perpendicular to the surface thereof (see Patent Document 1 and Patent Document 2).

The use of energy regeneration systems utilizing electric double layer capacitors is steadily evolving in many respects, and therefore, there is a need for a product that is less expensive and advantageous for mass production, and that can be used under more severe conditions, such as high temperature environments.

In addition, the shape of the energy regeneration system is required to be as short and thin as other electronic components and circuits, and it is desirable to have a large-capacity electric double-layer capacitor which is more efficient. Although the capacitance of the electric double layer capacitor is of course larger, the electric capacity of the electric double layer capacitor is as shown in the following formula [I], which is advantageous as the operating voltage is higher.

E=1/2CV ² [I]

In general, in an electric double-layer capacitor, although an organic electrolyte is used, it can operate at a higher voltage, but recently, with the progress of a constituent material, a higher voltage than an organic electrolyte-based electric double-layer capacitor is used. It is also possible. The method of measuring the actuation voltage will be described later.

In addition, in order to increase the capacity of the electric double layer capacitor, it is necessary to further reduce the thickness of the member and reduce the resistance of the polarization electrode. When the thickness of the member is reduced, the size and thickness of the electric double layer capacitor can be reduced, and the electric resistance of the electric double layer capacitor itself can be improved, and the capacity can be increased.

The carbon nanotubes have high conductivity, robustness, and high aspect ratio. Therefore, the effectiveness of the electron-emitting electron source has been widely noted and has been extensively reviewed. For example, a method of manufacturing an electric field radiation type cold cathode by transferring a vertically aligned carbon nanotube to a surface of a patterned conductive adhesive has been proposed (refer to Patent Document 3). A method for producing a three-layered sheet, which transfers a vertical alignment of a carbon nanotube to a functional sheet having various characteristics and fixes it to maintain alignment and improve handling convenience (refer to the patent literature) 4) A method of synthesizing a neatly arranged carbon nanotube layer on a first substrate capable of supporting growth of a carbon nanotube, and adding a layer of a second substrate composed of a polymer film to the same layer, The first substrate is removed to provide a carbon nanotube film that is supported and aligned on the second substrate (see Patent Document 5).

Patent Document 1: Japanese Laid-Open Patent Publication No. 2004- 127737. Patent Document 2: Japanese Laid-Open Patent Publication No. 2004-281388. 5: Japanese Special Table 2003-500325

As shown in Fig. 3, the carbon nanotube conductive material described in Patent Document 1 is a brush-like carbon nanotube (51) which grows with the catalyst particles on the substrate as a core, and is substantially perpendicularly It is formed by transferring onto the conductive film (52). However, since the conductive film (52) is added with the polyethylene layer (54), it is inferior in heat resistance and strength. Therefore, when the ambient temperature is equal to or higher than the melting temperature of the polyethylene, the carbon nanotubes (51) which are transferred to the conductive film (52) so as to penetrate substantially in the vertical direction become unable to maintain the vertical alignment. In the worse case, there is fear of falling off.

Further, since the conductive film of the polyethylene substrate, the porous film, and the polymer film of Patent Document 5 are inferior in strength, as shown in Fig. 4, the conductive film (52) and the layer are also used. The case of a multilayer film (56) composed of a reinforcing layer (55) on the film. However, in this case, the full thickness of the film is inevitably increased.

Further, in the step of transferring the carbon nanotubes, the conductive film before transfer is temporarily heated to a softening temperature or higher, and after being transferred and held for a certain period of time in this state, in order to hold the carbon nanotubes in the state The conductive film must be cooled below the softening temperature after it, and the series of steps takes a long time, resulting in poor productivity. Further, it can be seen that the transfer of the carbon nanotubes cannot be performed reliably, and the carbon nanotubes grown on the substrate remain, or the polyethylene layer of the conductive film is melted and peeled off. .

As shown in Fig. 5, the carbon nanotube conductive material described in Patent Document 2 is a carbon nanotube (63) grown by using catalyst particles on a substrate as a core, and is transferred onto a substrate ( 61) on the conductive adhesive layer (62). Although the adhesive is preferably a thermoplastic resin such as a polyvinyl chloride resin, the conductive material maintains the reliability of the carbon nanotubes at a high temperature higher than the heat resistance or the melting temperature as in the above Patent Document 1. Further, in the transfer step of the carbon nanotubes, in order to securely hold the carbon nanotubes, it takes a long time (for example, 10 to 30 minutes), so the productivity is still poor.

In the case where the conductive material is used as the polarization electrode of the electric double layer capacitor, the carbon nanotube after the transfer is adhered only to the surface of the adhesive layer, so that it is the same as the conductive material of Patent Document 1. There is a fear that the carbon nanotubes will fall off due to external factors such as temperature changes, so the reliability is poor.

Further, since the conductive adhesive layer is inferior in strength, it is necessary to apply a support such as a film, a sheet, or a thin plate made of an inorganic or organic synthetic resin to the conductive material to which the carbon nanotube is transferred, so that it is difficult to avoid. The ground causes an increase in the thickness of the electrically conductive material.

In addition, when the electroconductive material of the patent document 2 is used as a bipolar electrode for an electric double layer capacitor, the operating voltage is generated in a relatively low voltage region, so that it cannot withstand the electrolyte solution. The use of high voltage areas. Therefore, as a polarization electrode for a large-capacity electric double layer capacitor, the characteristic surface cannot be satisfied.

Patent Document 3 describes a method for producing an electrolytic radiation type cold cathode by a step of bonding an alignment carbon nanotube to a surface of a conductive adhesive layer patterned on a substrate, as needed. The step of hardening the conductive adhesive layer and the step of peeling off the substrate by leaving only the aligned carbon nanotube portion adhered to the conductive adhesive layer. Further, a method of transferring an alignment carbon nanotube to a flexible substrate having a reversible adhesive surface, and a method of fixing an alignment carbon nanotube to an electrode are described.

However, there is almost no description of the characteristics of the conductive adhesive in the method and the flexible substrate having a reversible adhesive surface, and in either case, the transferred carbon nanotubes are only adhered to the surface. Or adhere to the surface, rather than being completely fixed to maintain high reliability. Further, this transfer step is carried out under an argon atmosphere and under heating, and cooling is required thereafter, so that the production efficiency is inferior to that of Patent Document 1.

As shown in Fig. 6, Patent Document 4 proposes a functional sheet having a three-layer structure in an attempt to prevent contamination and improve convenience when transferring an aligned carbon nanotube. On the other hand, two functional sheets (72) (73) disposed on both sides of the aligned carbon nanotube film (71) have been fixed to the carbon nanotube film (71). The immobilization of the carbon nanotube film (71) is described, which means that the functional sheet (72) (73) is in contact with and adhered to the surface of the aligned carbon nanotube film (71). Therefore, in the case where the conductive material obtained by the patent document 4 is used as the electrode, as in the above-mentioned patent documents, there is a fear that the alignment of the carbon nanotubes is disordered or dropped, and the conductive material holds the carbon nanotubes. The reliability is poor and there is no way to use it.

Therefore, in the case where the conductive material obtained by the patent document 4 is used as the electrode, as in the above-mentioned patent documents, there is a fear that the alignment of the carbon nanotubes is disordered or dropped, and the conductive material holds the carbon nanotubes. The reliability is poor and there is no way to use it. This is also the case where the functional sheet of one side is peeled off and the functional sheet of the other side is hardened, whereby the carbon nanotube film is directly used after being immobilized, since the carbon nanotube film system is only utilized and The bonding of the surface of the functional sheet is maintained, so that the reliability of the carbon nanotube is still poor in the case where the conductive material is assumed to be an electrode.

Accordingly, an object of the present invention is to solve the problems of the above-mentioned patent documents, and to provide a conductive material using a carbon nanotube and a method of manufacturing the same, wherein the conductive material can be thinner and maintain high conductivity and strength. And maintaining the reliability of the carbon nanotubes, the production efficiency is also excellent and suitable for mass production, and the cost is also advantageous. In addition, since the conductive material can be thinner and maintain high conductivity and ensure operation in a high voltage region, the object of the present invention is to provide a large capacity for using the conductive material as a polar electrode. Electric double layer capacitor.

The present inventors have found that in order to solve the above problems, it has been found that in order to manufacture a thinner type and maintain high conductivity, the strength and the reliability of the carbon nanotube retention are excellent, the mass productivity is excellent, and the cost is favorable. The conductive material formed on the surface of the preformed epoxy resin composition by using a conductive material of a carbon nanotube, and the carbon nanotube is transferred through the same resin composition layer to form a conductivity. Materials and methods of manufacture thereof.

Further, in the case where the conductive material is used as the polarization-polarizing electrode, it has been found that a large-capacity electric double-layer capacitor can be formed by securing a low resistance and a high operating voltage.

That is, the present invention provides a conductive material using a carbon nanotube, which is characterized in that a carbon nanotube grown by using a catalyst particle on a substrate is transferred onto an epoxy resin composition layer. It is pierced in a direction substantially perpendicular to its surface, and is formed through the same resin composition layer.

The carbon nanotube of the present invention is transferred onto the epoxy resin composition layer and penetrated substantially perpendicularly to the surface thereof, and maintained in a state of penetrating through the same resin composition layer. The carbon nanotube system penetrates through the epoxy resin composition layer, so that it can be reliably maintained in the same resin composition layer, and the reliability of the carbon nanotube retention can be greatly improved as compared with the prior art.

The carbon nanotubes substantially aligned perpendicularly to the substrate can be produced by a known method. For example, a solution containing a complex of a metal such as nickel, cobalt, or iron is applied to at least one side of the substrate by a spray or a brush, and then heated to form a film layer, or the metal or the metal gun is used as a cluster gun. Particles of the compound are struck on the substrate to form a film layer. The film layer is preferably formed by heating the catalyst particles from the film layer in an inert gas atmosphere at a temperature of from 700 to 800 ° C for 1 to 30 minutes. The obtained particle shape is obtained by using a acetylene gas and performing a general chemical vapor deposition method (CVD method) to have a diameter of 10 to 38 nm, a length of 1 to 300 μm, and a spacing between the carbon nanotubes of 10 to 1000 nm. It is preferred that the carbon nanotubes are raised on the substrate in a multilayer structure.

It is preferable to use a multilayer structure of a carbon nanotube system, and it is preferable to have an outer diameter of 10 to 30 nm. An electric double layer capacitor formed by using such a carbon nanotube as a polarization electrode exhibits good charge and discharge characteristics.

The epoxy resin composition layer transferred with a carbon nanotube further comprises: a) a polyfunctional epoxy resin having three or more epoxy groups in the molecule, b) a phenoxy resin, and c) a synthetic rubber At least one of or a derivative thereof and d) a polyamide resin or a derivative thereof is preferred.

The epoxy resin composition contains at least one of the above components a) to d), whereby an appropriate amount of elasticity can be obtained, so that the carbon nanotube is easily transferred onto the epoxy resin composition layer and can be penetrated The carbon nanotubes were held in the state of the epoxy resin composition layer.

Further, it is preferable that the epoxy resin composition layer further contains a conductive filler. By adding the conductive filler, the electrical bonding between the carbon nanotubes is improved, the conductivity is improved, and the internal resistance of the obtained conductive material can be reduced.

The present invention also provides a method of producing a conductive material using a carbon nanotube. The method of the present invention is a method for producing a conductive material using a carbon nanotube, which is characterized in that a carbon nanotube grown by using catalyst particles on a substrate as a core is transferred to an epoxy resin composition layer. When the same resin composition layer is penetrated in a direction substantially perpendicular to the surface thereof, the same resin composition layer is heated to 50 ° C or more and 200 ° C or less before the transfer.

In the method for producing a conductive material of the present invention, it is preferred that the epoxy resin composition layer is in a B-stage (semi-hardened state) at the stage before the heating.

The epoxy resin composition contains at least one of the above components a) to d) so that an appropriate amount of elasticity can be obtained when transferred to a carbon nanotube, and the carbon nanotube can be easily passed through the same resin composition layer.

Further, when the same resin composition layer is heated under the above conditions, the carbon nanotube can be surely held while the carbon nanotube is inserted through the same resin composition layer. Further, since the thickness of the same resin composition layer and the substrate for forming the resin composition layer can be extremely reduced, the substrate can be peeled off immediately after the transfer of the same resin composition layer to the carbon nanotube. Obtaining the purpose of the conductive material. Therefore, a forced cooling step is not required after the transfer.

In addition, by heating the same resin composition layer in the state of the B phase, the patent application range for maintaining the carbon nanotube in a state in which the carbon nanotube is reliably penetrated through the same resin composition layer can be further improved. The effect of the invention of item 5.

The present invention provides an electric double layer capacitor characterized in that the conductive material is used as a polarization electrode. By using the conductive material as a polarization electrode to ensure low resistance and high operating voltage, a large-capacity electric double layer capacitor can be realized.

Further, in the present invention, by using the conductive material as a polarization-polarizing electrode and using an ionic liquid as the electrolytic solution, a large-capacity electric double-layer capacitor capable of securing a higher operating voltage can be realized.

The operating voltage of the electric double layer capacitor is determined by the potential window, which is derived based on the reaction current measured by the cyclic voltammety (CV) method. The potential window is in a range of a voltage region where no reaction current is generated. The larger the range, the higher the operating voltage can be secured, and the larger the capacity can be realized. The generation of the reaction current means that the amount of electricity temporarily charged in the electric double layer capacitor is lost to the outside, that is, in the voltage region where the reaction current is generated, it is difficult to operate the electric double layer capacitor.

According to the invention of claim 1, the conductive material of the present invention utilizes a structure in which a carbon nanotube is penetrated through the epoxy resin composition layer to optimize the strength and maintain the reliability of the carbon nanotube, and It is thinner and more conductive, and has a high operating voltage to ensure operation in a high voltage region. It has excellent production efficiency and is suitable for mass production, and is also advantageous in terms of cost.

Further, since the carbon nanotube is inserted through the epoxy resin composition layer, when the epoxy resin composition layer is formed on the substrate, it is in direct contact with the surface of the substrate. Therefore, in the case where a conductive material formed by raising a carbon nanotube on a laminate composed of an epoxy resin composition layer and the substrate is used as a collector electrode, a carbon nanotube can be found. The high conductivity has a multiplication effect with respect to the conductivity of the electrode itself, and a low resistance electrode can be formed.

According to the invention of claim 2, the epoxy resin composition layer further contains at least one of the specific components a) to d), and the epoxy resin composition is in addition to the above effects of the invention of claim 1 The layer also has an appropriate amount of elasticity, and therefore, the carbon nanotubes are easily transferred onto the epoxy resin composition layer, and the carbon nanotubes can be held in a state of penetrating through the epoxy resin composition layer.

According to the inventions of claims 3 and 4, the epoxy resin composition layer further comprises a conductive filler, and in addition to the above effects of the inventions of claims 1 and 2, by increasing the carbon nanotubes The electrical bonding property can improve the electrical conductivity, and the electrical resistance can reduce the internal resistance.

According to the invention of claim 5, the epoxy resin composition layer is heated to a specific temperature range before transfer so that the same resin composition layer has an appropriate amount of flexibility for transfer, after transfer The carbon nanotubes can be held in a state of penetrating through the same resin composition layer.

According to the invention of claim 6, the same resin composition layer before the heating is in the B-stage state, and the carbon nanotube can be surely passed through the same resin composition layer. The effect of the invention of claim 5 of the patent application scope of the carbon nanotubes is maintained.

According to the invention of claim 7, the conductive material of the present invention can be used as an electrode of an electric double layer capacitor, and can be made thinner and has a high operating voltage, thereby ensuring operation in a high voltage region and providing a large capacity. The material for the electric double layer capacitor.

According to the invention of claim 8 of the patent application, the above effects of the invention of claim 7 can be further improved.

(to implement the best form of invention)

Hereinafter, embodiments of the present invention will be described.

First, the formation of a carbon nanotube is explained.

The catalyst particles are formed on the substrate, and the carbon nanotubes are grown from the material gas in a high-temperature environment using the catalyst particles as a core. The substrate can support the catalyst particles, and it is preferable that the catalyst particles are not easily wetted, and it can be a tantalum substrate. The catalyst particles may be metal particles such as nickel, cobalt, or iron. A solution of a compound such as a metal or a complex thereof is applied onto a substrate by a spray or a brush to form a film layer. The thickness of the film layer is preferably from 1 to 100 nm. The film layer is preferably formed by heating the catalyst particles in an inert gas atmosphere at a temperature of from 700 to 800 ° C for 1 to 30 minutes.

As the raw material gas system of the carbon nanotube, an aliphatic hydrocarbon such as acetylene, methane or ethylene can be used, and acetylene is preferred. In the case of acetylene, a carbon nanotube having a multilayer structure and having a thickness of 12 to 60 nm is formed on the substrate by using a catalyst particle as a core by a CVD method. The formation temperature of the carbon nanotubes is preferably 650 to 800 °C.

Next, an epoxy resin composition will be described.

The epoxy resin used in the present invention may be one having two or more glycidyl groups in the molecule. Examples of the epoxy resin include a diglycidyl ether type, a diglycidyl ester type, a glycidylamine type, a linear aliphatic epoxy group, and an alicyclic epoxy group. These types may be used in one type, or a combination of two or more types may be used.

Further, the epoxy resin may be a denatured person according to a known method.

The epoxy resin may be either liquid, semi-solid or solid at room temperature, but for ease of handling, the epoxy resin composition preferably contains an organic solvent or a reactive diluent, alone or in combination. As the reactive diluent, various reactive diluents such as a monofunctional, bifunctional, or polyfunctional group can be suitably used. As the organic solvent, methanol, acetone, methyl ethyl ketone, toluene, methoxyethanol ether (MCS), dimethylformamide (DMF) or the like can be suitably used.

The epoxy resin composition contains a hardener, and the hardener is exemplified by aliphatic, alicyclic, aromatic, and the like polyamine; polyamine-amine; metamorphic polyamine; hexahydrophthalic anhydride, ten An acid anhydride such as dodecyl succinic anhydride or trimellitic anhydride; methylimidazole such as 2-methylimidazole or dimethyl-4-methylimidazole and derivatives thereof ; dicyandiamide or a derivative thereof; an organic acid diterpene such as sebacic acid dihydrazide; 3-(3,4-dichlorophenyl)-1,1-dimethyl A urea derivative such as urea or the like; a boron fluoride-ethylamine complex or a phenol resin, an amino resin, a polyisocyanate compound, or a 4,4-diaminodiphenyl sulphone. The curing agent can be used if it is subjected to a heavy addition reaction with an epoxy resin to be used and a crosslinking reaction is carried out by addition of a polymerization reaction, and is not particularly limited. The hardener may be used in one type or in a combination of two or more types.

Other thermosetting resins or thermoplastic resins may be mixed in the epoxy resin composition. In addition, in order to provide the necessary characteristics, organic and inorganic additives and fillers may also be added.

The epoxy resin composition layer preferably further comprises: a) a polyfunctional epoxy resin having three or more epoxy groups in the molecule, b) a phenoxy resin, c) a synthetic rubber or a derivative thereof, and d) at least one of a polyamine resin or a derivative thereof.

a) Examples of the polyfunctional epoxy resin having three or more epoxy groups in the molecule include a phenolic novolac type epoxy resin, an o-cresol novolac type epoxy resin, and a triglycidyl group. Triglycidyl-p-aminophenol, triglycidyl isocyanurate, tetraglycidyl metaxylene diamine, tetraglycidyl Diaminodiphenylmethane), a polyfunctional epoxy resin such as tetraglycidyl-1,3-bisaminomethyl cyclohexan. Considering epoxy Among these polyfunctional epoxy resins, a phenolic epoxy resin or an o-cresol epoxy resin is preferably used for the heat resistance of the composition layer and the ease of transfer of the carbon nanotubes. Further, when the polyfunctional epoxy resin is added to the epoxy resin composition, it is preferably added in an amount of 5 to 50 parts by weight based on 100 parts by weight of the same resin composition. When the amount added is less than 5 parts by weight or more than 50 parts by weight, transfer of the carbon nanotubes in the form of the same resin composition layer becomes difficult.

b) The phenoxy resin is a linear epoxy resin, generally having a molecular weight of 30,000 or more and having the properties of a thermoplastic resin. In the present invention, any of the bisphenol A type and the bisphenol F type may be used as the basic structure. Further, it is also possible to use a deflamability denatured by bromine, phosphorus or the like, which is formed by denaturation of other functional groups. As an example of such a denatured body, "phenotort" of Dongdu Chemical Industry Co., Ltd., etc. are mentioned. By adding 5 to 45 parts by weight of the phenoxy resin to the weight of 100 parts by weight of the same resin composition, an appropriate amount of rigidity and flexibility can be imparted. Therefore, the carbon nanotube can be formed in the form of the same resin composition layer. Transfer. If the amount added is less than 5 parts by weight or more than 50 parts by weight, the transfer of the carbon nanotubes through the same resin composition layer cannot be performed.

c) The synthetic rubber may be styrene-butadiene rubber, polyisoprene rubber, acrylonitrile-butadiene rubber, epichlorohydrin rubber or the like. The derivative of the synthetic rubber may be a derivative which is denatured by hydrogenation or carboxylation of a synthetic rubber. Medium-high nitrile type, high nitrile type acrylonitrile-butadiene rubber, carboxylated acrylonitrile-butadiene rubber, when transferring carbon nanotubes, an appropriate amount of softness can be obtained with an epoxy resin composition layer. Rigidity is preferred. As an example, "Nipol" manufactured by ZEON Corporation of Japan, etc. are mentioned. Since the synthetic rubber or its derivative is added to the epoxy resin composition to impart flexibility and rigidity to the epoxy resin composition layer, the carbon nanotube can be formed in the form of the same resin composition layer. Transfer.

Further, a so-called rubber-modified epoxy resin which denatures the synthetic rubber into an epoxy resin can also be used.

The amount of the synthetic rubber or its derivative added is 5 to 50 parts by weight based on 100 parts by weight of the epoxy resin composition. When the amount of addition is 5 parts by weight or less, it is difficult to transfer the carbon nanotubes in the same resin composition layer, and if it is 50 parts by weight or more, it is difficult to keep the carbon nanotubes after transfer in the same state. Resin composition layer.

In order to improve the strength and adhesion of the rubber itself, a suitable sulfurizing agent such as a phenol resin or a derivative thereof may be used in combination with a synthetic rubber or a derivative thereof. The phenol resin and its derivative are preferably added in an amount of 5 to 20 parts by weight based on 100 parts by weight of the synthetic rubber or a derivative thereof.

d) The basic structure of the polyamide resin may be any of nylon 6, nylon 66, or the like, or a copolymer of the nylons. As an example, CM4000 and CM8000 of the nylon copolymer "Amilan" manufactured by Toray Industries, Inc. are mentioned. In addition, an elastomer or a synthetic resin having a polyamine group in a molecular structure such as "Kayaflex" manufactured by Nippon Kayaku Co., Ltd. may be used. The polyamide resin or a derivative thereof may be in the form of powdery fine particles or a liquid or solid at room temperature, or may be added in an amount of a solvent such as dissolved or dispersed in an organic solvent. .

By the addition of a polyamide resin or a derivative thereof, an appropriate amount of flexibility and retention can be imparted to the same resin composition layer at the time of transfer of the carbon nanotubes.

The amount of the polyamide resin or its derivative added is preferably from 5 to 60 parts by weight based on 100 parts by weight of the epoxy resin composition. When the amount of addition is 5 parts by weight or less, the flexibility of the resin composition layer is insufficient, and when it is more than 60 parts by weight, it is difficult to hold the carbon nanotube after transfer in the same resin composition layer.

In order to further impart conductivity to the conductive material of the present invention, it is preferred that the epoxy resin composition contain a conductive filler. Examples of the conductive filler include a carbon-based conductive sheet such as a carbon nanotube sheet, a nano-carbon sheet, a nano-carbon ring sheet, conductive carbon cellulose, black lead, and carbon black, or a carbon-based conductive powder. When the conductive material is used for an electric double layer capacitor, the electrolyte solution and the like are not affected, and the resistance of the electrode itself can be reduced.

Next, the transfer of the carbon nanotubes will be described.

First, an epoxy resin composition is applied on the surface of a substrate made of an inorganic material such as a metal foil or a heat-resistant film by an applicator, a plate, or the like to form an epoxy resin composition layer. From the standpoint of ease of scheduling or economy, the metal foil is preferably copper foil, stainless steel foil, or aluminum foil. The heat resistant film is preferably a polyethylene terephthalate film.

The thickness of the epoxy resin composition layer is preferably 0.1 to 1000 μm, more preferably 10 to 200 μm. When the thickness of the same resin composition layer is less than 0.1 μm, the carbon nanotubes cannot be reliably held, and when it is larger than 1000 μm, it is difficult to form the same resin composition layer, and the productivity is poor.

The transfer step of the carbon nanotube layer to the epoxy resin composition layer is carried out after the epoxy resin composition is applied to the surface of the substrate, and the solvent is evaporated to dry the same resin composition.

Further, an epoxy resin composition may be applied to a substrate made of a metal foil or a heat-resistant film having a suitable mold release property, and after drying, from the laminate of the same resin composition and the substrate. The same resin composition layer was peeled off to form a film of an epoxy resin composition, and a carbon nanotube was transferred onto the epoxy resin composition layer.

From the front end, the carbon nanotubes grown on the substrate are pressed against the epoxy resin composition layer to be rooted on the same resin composition layer. Then, the carbon nanotubes were left on the same resin composition layer, and only the substrate was peeled off from the carbon nanotubes.

Accordingly, the transfer of the carbon nanotubes from the substrate to the epoxy resin composition layer is completed, and a conductive material obtained by using a brush-shaped carbon nanotube can be obtained. The brush-shaped carbon nanotubes are inserted through the epoxy resin composition layer and can be reliably transferred onto the epoxy resin composition layer.

The epoxy resin composition layer at the time of transfer is preferably 50 ° C or more and 200 ° C or less, more preferably 60 ° C to 160 ° C. This heating is preferably carried out by far infrared ray or electromagnetic induction heating. The heating time can be, for example, 1 to 20 minutes, more preferably 3 to 10 minutes. By performing the transfer of the carbon nanotube under the conditions of the temperature range, the same resin composition layer is heated to a temperature having an appropriate amount of flexibility for transfer, so that the carbon nanotube after the transfer becomes penetrated. In the state of the epoxy resin composition layer, the carbon nanotubes can be surely maintained in a penetrating state even after the transfer is completed. When the temperature of the epoxy resin composition layer is 50° C. or less, the transfer cannot be performed in a state in which the carbon nanotubes are penetrated. When the temperature is 200° C. or more, it is difficult to maintain the vertical direction when the carbon nanotubes are transferred. The state of the alignment.

Further, the same-resin composition layer is preferably in the state before the heating, in the state of the B stage. With the state of being in the B stage, the carbon nanotubes can more reliably penetrate the same resin composition layer.

After the carbon nanotubes are transferred to the epoxy resin composition layer, the epoxy resin composition layer can be hardened by heating or the like as needed. Thereby, the carbon nanotube can be surely fixed in a state in which the carbon nanotube is penetrated through the epoxy resin composition layer.

The carbon nanotube system penetrates the epoxy resin composition layer substantially vertically, and is in a state of penetrating the epoxy resin composition layer and reaching the opposite side.

Finally, an electric double layer capacitor using a carbon nanotube is described.

The electrically conductive material of the present invention is used as a bipolar electrode to form an electric double layer capacitor. For example, a carbon nanotube of one electrode is opposed to a carbon nanotube of the other electrode in a non-contact manner to cause electrolysis. The liquid is impregnated on the carbon nanotubes and all of the components are placed in the container.

[Examples]

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited thereto.

[First Embodiment]

(1st step) First, a bisphenol A type solid epoxy resin (Asahi Kasei Co., Ltd.) is applied to a base material (1) made of a polyethylene terephthalate film by a plate or the like. Manufacture, "AER-6051"), dicyandiamide as a curing agent, phenolic-type denatured epoxy resin as a polyfunctional epoxy resin ("EPYCRON N-770", manufactured by Dainippon Ink and Chemicals Co., Ltd.), and organic solvent for dilution The epoxy resin composition composed of methyl ethyl ketone, and the coating thickness is 10 μm, and is heated at 150 ° C for 3 minutes to evaporate the organic solvent to form a B-stage epoxy resin composition layer. (2).

(Step 2)

In Fig. 1b, a carbon nanotube (4) having a diameter of 10 nm, a length of 200 μm, and a spacing of 100 nm between carbon nanotubes is grown on the tantalum substrate (3) by using a catalyst particle as a core by a CVD method. , a substrate (5) with a carbon nanotube attached thereto.

(Step 3)

In Fig. 1c, the carbon nanotube-attached substrate (5) and the epoxy resin composition layer (2) are heated to 130 ° C by far infrared rays, and from the front end of the carbon nanotube, the nanometer is attached. The substrate (5) of the carbon tube is pressed against the surface of the same resin composition layer (2), and as shown in Fig. 1d, the front end portion is inserted into the epoxy resin composition layer (2) to penetrate the same composition layer ( 2). The front end of the carbon nanotube is in contact with the substrate (1).

(Step 4)

Next, as shown in Fig. 1e, the tantalum substrate (3) is mechanically peeled off from the carbon nanotube (4) so that the carbon nanotube (4) remains on the epoxy resin composition layer (2). . Thus, the transfer of the carbon nanotubes from the substrate to the epoxy resin composition layer is completed. The carbon nanotube (4) is not left on the ruthenium substrate (3), and the carbon nanotube transfer from the ruthenium substrate (3) to the epoxy resin composition layer can be performed without any problem.

(Step 5)

The substrate (1) with the epoxy resin composition layer embedded in the obtained carbon nanotubes was heated in an oven at 150 ° C to harden the epoxy resin composition layer (2).

(Step 6)

After hardening, mechanically from the epoxy resin hardened layer (6) The material (1) was peeled off, and as shown in Fig. 1f, a conductive material (7) in which the carbon nanotube (4) was rooted on the epoxy resin cured layer (6) was obtained. It was confirmed that the carbon nanotube (4) was punctured substantially perpendicularly to the surface of the epoxy resin cured layer (6), and penetrated the same resin cured layer (6) and reached the opposite side.

[Second Embodiment]

(Step 1)

In the second embodiment, the conductive carbon cellulose which is 10 parts by weight based on 100 parts by weight of the epoxy resin composition is added to the conductive filler, and the epoxy resin used in the first step of the first embodiment is used. The mixture obtained in the inside was applied to an aluminum foil (8) having a thickness of 25 μm to form an epoxy resin composition layer (2), and the same operation as in the first embodiment was carried out.

(Steps 2 to 5)

In the second to fifth steps, the same operations as those corresponding to the first embodiment are performed. It was confirmed that the carbon nanotubes (4) were punctured substantially perpendicularly to the epoxy resin composition layer (2), and penetrated into the same resin composition layer (2). As in the first embodiment, the carbon nanotube transfer of the epoxy resin composition layer (2) from the tantalum substrate can be carried out without using a carbon nanotube on the tantalum substrate.

(Step 6)

After hardening, the aluminum foil (8) is mechanically peeled off from the epoxy resin cured layer to obtain a conductive material in which a carbon nanotube is rooted on the epoxy resin cured layer. It was confirmed that the carbon nanotubes (4) were punctured substantially perpendicularly to the surface of the cured epoxy resin layer, and penetrated the same resin cured material layer to reach the opposite side.

[Third embodiment]

The conductive material obtained in the first and second embodiments is used as a polar electrode, and the electrolyte is N, N-diethyl-N-methyl-N-(2) which is an ionic liquid. A - methoxyethyl) ammonium salt (having a potential window up to 5.5 V) was fabricated into an electric double layer capacitor.

A voltage was applied between the positive electrode and the negative electrode of the electric double layer capacitor, and the reaction current was measured by cyclic voltammetry. As a result, it was found that the reaction current was not confirmed in the potential window region up to 3.5 V, and it was possible to operate as an electric double layer capacitor in a high voltage region.

[First Comparative Example]

(First step) A conductive adhesive having a thickness of 10 μm and a thermoplastic resin (polyvinyl chloride) as a binder is applied to a substrate made of a polyethylene terephthalate film, and an organic binder is applied. The solvent is evaporated to dry the coating layer to form a conductive adhesive layer.

(Second Step) The same operation as in the second step of the first embodiment was carried out to prepare a substrate with a carbon nanotube.

(Step 3) The substrate with the carbon nanotubes is pressed against the conductive adhesive layer from the front end of the carbon nanotube at a normal temperature, and the front end portion is inserted into the conductive adhesive layer. . Then, it takes 10 minutes until the conductive adhesive layer is sufficiently cured.

(Fourth Step) Next, the tantalum substrate is mechanically peeled off from the carbon nanotubes so that the carbon nanotubes remain on the conductive adhesive layer. Thus, the transfer of the carbon nanotubes from the substrate to the epoxy resin composition layer is completed. However, a part of the carbon nanotubes remained on the substrate, and the transfer could not be performed satisfactorily.

(Fifth Step) Although the substrate is to be peeled off from the substrate to which the conductive adhesive layer for transferring the carbon nanotubes is mechanically attached, the conductive adhesive layer is broken. Further, although the carbon nanotubes were punctured substantially perpendicularly to the conductive adhesive layer, they did not penetrate the conductive adhesive layer and reached the opposite side.

(industrial availability)

The conductive material of the present invention can be applied, for example, as a polarization-polarizing electrode, and the polarization-polarizing electrode can be a main component of an electric double-layer capacitor that can store a large amount of electricity.

1‧‧‧Substrate

2‧‧‧Epoxy resin layer

3‧‧‧矽 substrate

4‧‧‧Nano Carbon Tube

5‧‧‧Substrate with carbon nanotubes

6‧‧‧Epoxy resin hardened layer

7‧‧‧Electrical materials

8‧‧‧Aluminum foil

Fig. 1a is a cross-sectional view schematically showing a first step of the first embodiment.

Fig. 1b is a cross-sectional view schematically showing a second step of the first embodiment.

Fig. 1c is a cross-sectional view schematically showing a third step of the first embodiment.

Fig. 1d is a cross-sectional view schematically showing a third step of the first embodiment.

Fig. 1e is a cross-sectional view schematically showing a fourth step of the first embodiment.

Fig. 1f is a cross-sectional view schematically showing a sixth step of the first embodiment.

Fig. 2 is a cross-sectional view schematically showing a first step of the second embodiment.

Fig. 3 is a cross-sectional view showing the carbon nanotube conductive material of Patent Document 1.

Fig. 4 is a cross-sectional view showing the carbon nanotube conductive material of Patent Document 1.

Fig. 5 is a cross-sectional view showing the carbon nanotube conductive material of Patent Document 2.

Fig. 6 is a cross-sectional view showing the carbon nanotube conductive material of Patent Document 4.

4‧‧‧Nano Carbon Tube

6‧‧‧Epoxy resin hardened layer

7‧‧‧Electrical materials

Claims (5)

A method for producing a conductive material using a carbon nanotube, which is characterized in that the epoxy resin composition layer (B) having a B-stage state and containing a hardener is formed on a substrate (1) composed of a film (2) a step of growing a carbon nanotube (4) on the substrate (3) with the catalyst particles as a core, and forming a substrate with a carbon nanotube substantially aligned perpendicularly to the substrate (3) (5) The step of heating the substrate (5) with the carbon nanotubes and the epoxy resin composition layer (2) to 50 ° C or more and 200 ° C or less, from the front end of the carbon nanotubes, will be attached with nano carbon The substrate (5) of the tube is pressed against the surface of the same resin composition layer (2), and the front end portion is inserted into the epoxy resin composition layer (2) to penetrate the same composition layer (2) to make the nanocarbon a step of abutting the end portion of the tube against the substrate (1); then, the substrate (3) is self-carbonized by leaving the carbon nanotube (4) on the epoxy resin composition layer (2) (4) a step of peeling off; a step of hardening the epoxy resin composition layer (2) with the substrate (1) in which the epoxy resin composition layer of the obtained carbon nanotube is embedded; after hardening, self-hardening Epoxy resin hardening The substrate (1) composed of a film is peeled off from the layer (6) to obtain a conductive material (7) having the carbon nanotube (4) rooted on the epoxy resin cured layer (6); nanocarbon The tube (4) is substantially perpendicularly penetrating the surface of the cured epoxy resin layer (6), and is in a state of passing through the same resin cured layer (6) and reaching the opposite side. The method for producing a conductive material using a carbon nanotube according to claim 1, wherein the epoxy resin composition layer containing the hardener comprises a material of at least one of the columns: a) 5 to 50 parts by mass of a polyfunctional epoxy resin having 3 or more epoxy groups in the molecule, and b) relative to the ring with respect to 100 parts by mass of the epoxy resin composition 5 to 45 parts by mass of the phenoxy resin in 100 parts by mass of the oxygen resin composition, c) 5 to 50 parts by mass of the synthetic rubber or a derivative thereof, and d) relative to 100 parts by mass of the epoxy resin composition 5 to 60 parts by mass of the polyamide resin or a derivative thereof in an amount of 100 parts by mass of the epoxy resin composition. The method for producing a conductive material using a carbon nanotube according to the first aspect of the invention, wherein the epoxy resin composition layer further comprises a conductive filler. An electric double layer capacitor characterized by using a conductive material produced by the method for producing a conductive material according to any one of claims 1 to 3 as a polarization electrode. An electric double layer capacitor, which is characterized in that a conductive material produced by the method for producing a conductive material according to any one of claims 1 to 3 is used as a polar electrode, and an electrolyte is used as an ion. Sexual liquid.