JP2019142755A - Nanocarbon material dispersion method, nanocarbon material dispersion liquid, and nanocarbon material complex - Google Patents

Abstract

To provide a nanocarbon material dispersion method and a nanocarbon material dispersion liquid that can maintain an excellent dispersion state without impairing the original nature of carbon nanotubes and even after a lapse of time.SOLUTION: Powder materials suitably prepared from carbon nanotubes and other types of nanocarbon materials are used; the powder materials are added to an aqueous solution containing a suitable surfactant to apply an ultrasonic treatment or a meander flow passage structure agitation treatment thereto; and a dispersion liquid of nanocarbon materials can be obtained with extremely good dispersibility.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a nanocarbon material dispersion method, a nanocarbon material dispersion, and a nanocarbon material composite, and in particular, by applying an unprecedented dispersant and dispersion treatment method, the dispersibility and electrical characteristics are excellent. The present invention relates to a technique for providing a nanocarbon material dispersion and a nanocarbon material composite.

  Conventionally, it has been clarified that carbon has a plurality of allotropes having greatly different properties such as graphite, diamond, and amorphous carbon. Nanometer-sized carbon allotropes that have been newly discovered since the 1980s have been confirmed to have completely different atomic structures and physical properties from the conventionally known carbon allotropes. Has been. In the present specification, these are referred to as “nanocarbon materials”, and are carbon nanotubes, carbon nanofibers, nanographene, fullerenes, carbon nanohorns, carbon microcoils, carbon black, diamond-like carbon, carbon nanocrystals, activated carbon, etc. The one having a size of about 10 nm to 10 μm is included.

Since the nanocarbon material is composed only of carbon, it is a polymer material that is extremely lightweight, high in strength, and conductive. Its conductivity is superior to copper, strength is superior to steel, heat resistance is high, it does not react to many chemicals, and is stable in the atmosphere.
Among nanocarbon materials, carbon nanotubes exhibit particularly excellent electrical properties, mechanical properties, thermal properties, etc., and are expected to be applied to various materials, and are widely researched and developed. For example, a material for various uses can be obtained from a composite material in which carbon nanotubes and a resin are mixed, or a carbon nanotube dispersion mixed with a binder and dried.

  Carbon nanotubes have the property of agglomerating due to van der Waals forces and form a bundle structure in the solution. Therefore, it is impossible to produce a good carbon nanotube composite as it is, and the carbon nanotubes are dispersed in the solution ( Alternatively, a step of solubilization is required. Since the use of a solution (dispersion) in which carbon nanotubes are well dispersed greatly contributes to the improvement of the characteristics of the carbon nanotube composite material, many proposals have been made regarding techniques for stably dispersing carbon nanotubes in a solution. ing.

  As a method for dispersing carbon nanotubes in a solution, a method using an organic solvent (for example, N-methylpyrrolidone; NMP), a method for chemically modifying carbon nanotubes by acid treatment, a surfactant (for example, sodium dodecyl sulfate; SDS) There is a method of forming micelles, and ultrasonic treatment and bead mill treatment are often used together.

  Patent Document 1 proposes a carbon nanotube dispersion containing a surfactant having an alkyl ester group, a vinylidene group and an anionic group, carbon nanotubes, and an aqueous solvent (claim 1 and the like). In this dispersion technique, the carbon double bond possessed by the vinylidene group of the surfactant interacts with the carbon nanotubes to promote the dispersion of the carbon nanotubes, such as conventional sodium dodecyl sulfate (SDS). Compared with the case where a dispersant is used, the degree of dispersion is high ([0055] to [0062], etc.) and the stability against pH change ([0063] to [0069] etc.) is also obtained. Results have been reported.

  Patent Document 2 discloses a composite material of carbon nanotubes and a manufacturing method thereof. Specifically, the carbon nanotubes produced by the arc discharge method are pulverized, the pulverized carbon nanotubes and activated carbon are added to acetone, and mixed and dispersed using ultrasonic waves to produce a composite material. A powder composite material is produced by drying in a draft chamber, and the composite material is heated to burn and remove a part of the activated carbon, thereby exposing the carbon nanotubes in a state of high density and uniform dispersion. At that time, some of the carbon nanoparticles are also burned away.

  Patent Document 3 discloses a stirring device in which a circulation path for fluid is formed. Specifically, the fluid agitation unit provided in the agitation layer is a rotation center of one agitation body by integrally rotating a pair of agitation bodies arranged coaxially in an opposed state around the same axis. The fluid that has flowed in through the inflow part formed in the central part flows in the radial direction through the stirring channel formed between both stirring bodies, and flows out from the outflow part formed between the outer peripheral edges of both stirring bodies. In addition, the other agitator is provided with a guide portion so that the fluid flowing out from the outflow portion flows to the inflow portion formed in the one agitator, and the inflow portion is interposed through the guide portion. The fluid is circulated in the air.

  Patent Document 4 discloses a stirring device that promotes stirring efficiency. Specifically, a fluid agitation unit equipped in an agitation device for agitating fluid, wherein the fluid agitation unit rotates a pair of agitation bodies arranged coaxially in an opposed state around the same axis, The fluid that has flowed in through the inflow portion formed in the central portion, which is the rotation center of the stirring body, was caused to flow in the radial direction through the stirring flow path formed between the two stirring bodies, and formed between the outer peripheral edges of both stirring bodies. The stirring channel is configured to flow out from the outflow part, and the cross-sectional area of the stirring channel is gradually reduced from the inflow part side to the outflow part side, and one stirring body is formed in the stirring channel. The one side meandering channel forming piece projecting from the other stirring body toward the other stirring body and the other side meandering channel forming piece projecting from the other stirring body toward the one stirring body The fluid flowing in from the inflow section It is obtained so as to be agitated to flow in a meandering state to the outflow part side while flowing overflow line flow path forming member.

  Patent Document 5 discloses a mixing and stirring device that can be mixed and stirred more efficiently to form a mixture. Specifically, the mixing stirring case forming the mixing stirring chamber is connected to a feeding path for feeding a plurality of types of fluids to be mixed and stirred, and a delivery path for sending the mixed and stirred mixture. Connect and rotate the rotating shaft linked to the rotation drive source in the mixing stirring case, and attach the rotating side mixing stirring body to the rotating shaft, while the mixing side stirring stirrer on the fixed side mixing stirring body A mixed stirring channel is formed between the two mixing agitators, which are fixed in a face-to-face configuration, and extend while meandering in the radial direction from the center to the periphery. The introduction port formed by opening in the central part of the body is communicated, and the outlet port formed between the peripheral portions of the two mixed stirring bodies is communicated.

JP 2010-13312 A JP 2006-45034 A JP 2008-284492 A JP 2010-260031 A JP 2012-200715 A

The carbon nanotube dispersion using an organic solvent such as NMP or a surfactant such as SDS is problematic in that the carbon nanotubes agglomerate again over time and the organic solvent and surfactant are impurities in the produced nanocarbon material. The problem of remaining as is not solved.
The method of chemically modifying carbon nanotubes by acid treatment is to covalently introduce functional groups having an affinity for the solvent to the surface of the carbon nanotubes. The problem of being done is not solved.

  The present invention has been made in view of such circumstances, and a method for dispersing a nanocarbon material that can maintain a good dispersion state even after a lapse of time without impairing the inherent properties of carbon nanotubes And a dispersion of the nanocarbon material, and a nanocarbon material composite obtained thereby.

As a result of diligent research in view of the above-mentioned problem, the present inventor
(1) Using a powder material suitably prepared from carbon nanotubes and other types of nanocarbon materials,
(2) A dispersion of nanocarbon material having extremely excellent dispersibility is obtained by adding the above powder material to an aqueous solution containing a suitable surfactant and performing ultrasonic treatment or meandering channel structure stirring treatment. The present invention has been made.
Here, the meandering channel structure stirring process refers to a process of stirring by rotating a rotating blade or a disk-shaped stirring body having a structure for forming a meandering channel with a motor.
This will be specifically described below.

Preparation of powder of carbon raw material Carbon nanotube (multi-walled carbon nanotube; MWNT, preferably having an average diameter of 1 to 100 nm and an average length of 1 to 10 μm) is a main material, and this is a nano-order size (average A carbon material pulverized to a particle size of 20 nm to 10 μm is mixed with a weight ratio of 1 to 30% (more preferably 10 to 20%) to obtain a nanocarbon material powder.
The carbon material mixed with the carbon nanotube powder is preferably one type or two or more types of graphene, carbon black, and activated carbon. Further, instead of or in addition to these, carbon nanofibers, fullerenes, carbon nanohorns, carbon microcoils, diamond-like carbon, carbon nanocrystals, and the like may be used.

Preparation of Solvent A solution obtained by adding an anionic surfactant or a nonionic surfactant having a weight ratio of 0.01 to 10% to an aqueous solution containing 10 to 100% by weight of a lower alcohol is used as a solvent.
The lower alcohol is preferably one or more of methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol, ethylene glycol, diethylene glycol, propylene glycol and glycerin.
As the anionic surfactant or the nonionic surfactant, it is preferable to use one or more of sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, triethanolamine lauryl sulfate, and dodecyl itaconate.

Dispersion treatment A dispersion treatment is performed by subjecting a solution obtained by adding the powder of the nanocarbon material to the solvent to an ultrasonic treatment or a meandering channel structure stirring treatment.
The dispersion of the nanocarbon material of the present invention thus obtained has excellent dispersibility, and the nanocarbon material dispersion obtained by the prior art reaggregates over time from several hours to several days. On the other hand, the dispersibility is almost the same as that immediately after the dispersion treatment even after several days.

  Such excellent dispersibility prevents nano-order-sized carbon materials other than carbon nanotubes contained in the powder of nano-carbon materials from entering between the carbon nanotubes and being fixed, thereby preventing the carbon nanotubes from aggregating with each other. Further, it is considered that the dispersion ability of the anionic surfactant or nonionic surfactant added to the solvent is enhanced by ultrasonic treatment or meandering channel structure stirring treatment. .

Drying process The nanocarbon material dispersion liquid in a slurry state by the dispersion process is evaporated and dried by high-temperature stirring with a stirrer or the like to obtain a powder. At this time, since the lower alcohol and the anionic surfactant or nonionic surfactant contained in the dispersion are volatilized, a powder having a high carbon component purity can be obtained. This powder was confirmed to have remarkably superior electrical properties (low electrical resistance) compared to simple substances of various carbon materials pulverized to a nano-order size.

Production of nano-carbon material composite The above-mentioned powder is molded together with a substrate substance (or binder) such as a resin material to obtain the nano-carbon material composite of the present invention. This nanocarbon material composite was confirmed to have significantly superior electrical properties (low electrical resistance) compared to conventional nanocarbon material composites.

Summary of the Invention Based on the above findings, the present invention provides an anionic surfactant or a nonionic surfactant having a weight ratio of 0.01 to 10% with respect to an aqueous solution containing 10 to 100% by weight of a lower alcohol. In a solution obtained by adding a powder obtained by adding a carbon material having an average particle diameter of 10 nm to 10 μm with a weight ratio of 1 to 30% to a carbon nanotube in a solvent to which carbon is added, ultrasonic treatment or a meandering channel structure The present invention provides a method for dispersing a nanocarbon material that is subjected to a dispersion treatment by performing a stirring treatment.

  In the nanocarbon material dispersion method of the present invention, the carbon material includes one or more of graphene, carbon black, and activated carbon.

  In the nanocarbon material dispersion method of the present invention, the carbon material includes one or more of carbon nanofibers, fullerenes, carbon nanohorns, carbon microcoils, diamond-like carbon, and carbon nanocrystals. To do.

  In the method for dispersing a nanocarbon material of the present invention, the lower alcohol includes one or more of methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol, ethylene glycol, diethylene glycol, propylene glycol, and glycerin. It is characterized by that.

  In the method for dispersing a nanocarbon material of the present invention, the anionic surfactant or the nonionic surfactant is one of sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, triethanolamine lauryl sulfate, and dodecyl itaconate. It is characterized by including a kind or two or more kinds.

  In the method for dispersing a nanocarbon material according to the present invention, the carbon nanotube is a multi-walled carbon nanotube.

  In the method for dispersing a nanocarbon material according to the present invention, the carbon material having a weight ratio of 10 to 20% is mixed with the carbon nanotube.

  The present invention also relates to an aqueous solution containing a lower alcohol in a weight ratio of 10 to 100%, a weight ratio of 1 to a carbon nanotube in a solvent to which an anionic surfactant of 0.01 to 100% by weight is added. Nanocarbon obtained by performing a dispersion treatment by subjecting a solution obtained by adding a powder mixed with a carbon material having an average particle diameter of 10 nm to 10 μm to -30% to ultrasonic treatment or a meandering channel structure stirring treatment A dispersion of the material is provided.

  In the nanocarbon material dispersion of the present invention, the carbon material includes one or more of graphene, carbon black, and activated carbon.

  In the nanocarbon material dispersion of the present invention, the carbon material includes one or more of carbon nanofibers, fullerenes, carbon nanohorns, carbon microcoils, diamond-like carbon, and carbon nanocrystals. To do.

  In the dispersion of the nanocarbon material of the present invention, the lower alcohol includes one or more of methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol, ethylene glycol, diethylene glycol, propylene glycol, and glycerin. It is characterized by that.

  In the dispersion of the nanocarbon material of the present invention, the anionic surfactant or nonionic surfactant is one of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, triethanolamine lauryl sulfate, and dodecyl itaconate. It is characterized by including a kind or two or more kinds.

  In the dispersion liquid of the nanocarbon material of the present invention, the carbon nanotube is a multi-walled carbon nanotube.

  In the dispersion liquid of the nanocarbon material of the present invention, the carbon material having a weight ratio of 10 to 20% is mixed with the carbon nanotube.

  The present invention also provides a nanocarbon material composite comprising a powder obtained by drying the dispersion of nanocarbon material and a resin material or a metal material.

  As described above, according to the present invention, the nano-tube that has an unprecedented high dispersibility that maintains a good dispersion state even after a lapse of time without impairing the properties inherent to the carbon nanotube. Disclosed are a carbon material dispersion method, a nanocarbon material dispersion, and a nanocarbon material composite using these as a raw material.

It is a figure which shows the observation result of the dispersibility of a dispersion liquid about Example 1 and the comparative example of the dispersion method of a nano carbon material of this invention, and the dispersion liquid of a nano carbon material. It is a figure which shows the state which observed the molded object surface of the nanocarbon material composite concerning Example 1 of this invention with the scanning electron microscope. It is a figure which shows the state which observed the molded object surface of the nanocarbon material composite concerning Example 1 of this invention with the scanning electron microscope. It is a figure which shows the observation result of the dispersibility of a dispersion liquid about Example 2 and the comparative example of the dispersion method of a nano carbon material of this invention, and the dispersion liquid of a nano carbon material. It is a figure which shows the observation result of the dispersibility of a dispersion liquid about Example 3 of the dispersion method of a nano carbon material of this invention, and the dispersion liquid of a nano carbon material. It is a figure which shows the observation result of the dispersibility of a dispersion liquid about Example 4 and the comparative example of the dispersion method of a nano carbon material of this invention, and the dispersion liquid of a nano carbon material. It is a figure which shows the observation result of the dispersibility of a dispersion liquid about Example 5 and the comparative example of the dispersion method of a nano carbon material of this invention, and the dispersion liquid of a nano carbon material. It is a figure which shows the observation result of the dispersibility of a dispersion liquid about Example 6 of the dispersion method of a nano carbon material of this invention, and the dispersion liquid of a nano carbon material. It is a table | surface which lists an Example and a comparative example.

  Hereinafter, the best mode for carrying out a nanocarbon material dispersion method, a nanocarbon material dispersion, and a nanocarbon material composite of the present invention will be described in detail with reference to the accompanying drawings.

  Examples of the nanocarbon material dispersion method, nanocarbon material dispersion, and nanocarbon material composite of the present invention include specific methods for producing the nanocarbon material dispersion and nanocarbon material composite and the physical properties thereof. The test results will be described.

Preparation of carbon raw material powder 0.1 g of multi-walled carbon nanotube (Nanocyl, NC7000 (average diameter 9.5 nm, average length 1.5 μm, specific surface area 250-300 m 2 / g, carbon purity 90%)) and graphite・ Nanoplatelet (scale-scale graphite powder of nanometer order; manufactured by TCNT) and carbon black powder (CABOT, BP2000) 0.05 g are mixed to obtain a powder of nanocarbon material Adjusted.
Preparation of Solvent Sodium dodecyl sulfate (0.05 g) was dissolved in 16 ml of ethanol and 4 ml of water to prepare a solvent.

Dispersion treatment The solution obtained by adding the powder of the above-mentioned nanocarbon material to the above-mentioned solvent is subjected to an ultrasonic homogenizer (Mitsui Electric Seiki Co., Ltd., model: UX-600, oscillation frequency 20 ± 1 KHz, maximum output 600 W) for 20 minutes. Ultrasonic was irradiated to obtain a carbon nanotube dispersion.

Comparative Example As a comparative example for Example 1 above, a carbon nanotube dispersion was prepared by the following four methods.
(Comparative Example 1-A) A carbon nanotube dispersion (Comparative Example 1-B) obtained by adding 0.1 g of multi-walled carbon nanotubes (same as above) to 20 ml of water and subjecting to ultrasonic treatment in the same manner as described above (Comparative Example 1-B) Carbon obtained by adding a powder obtained by mixing 0.1 g of carbon black powder (same as above) and 0.05 g of carbon black powder (same as above) to a solvent composed of 16 ml of ethanol and 4 ml of water, and performing ultrasonic treatment as described above. Nanotube dispersion (Comparative Example 1-C) A solvent comprising 16 ml of ethanol and 4 ml of water prepared by mixing 0.1 g of multi-walled carbon nanotubes (same as above) and 0.05 g of graphite nanoplatelet (same as above) And a carbon nanotube dispersion liquid (Comparative Example 1-D) obtained by performing the same ultrasonic treatment as described above. A powder prepared by mixing 0.1 g of carbon black powder (same as above) and 0.05 g of graphite nanoplatelet (same as above) was added to a solvent composed of 16 ml of ethanol and 4 ml of water, Carbon nanotube dispersion obtained by sonication similar to the above

Dispersibility test results Carbon nanotube dispersions (Comparative Example 1-A) to (Comparative Example 1-D) according to the above comparative example, and a carbon nanotube dispersion (Example 1-E) according to Example 1 of the present invention Were made almost simultaneously, sealed and stored in a storage container, and allowed to stand at room temperature, and the course of 5 days was observed. The observation results are shown in FIG.
In FIG. 1, the dispersion liquid (Comparative Example 1-B), (Comparative Example 1-C), (Comparative Example 1-D), and (Example 1-E) are moderately dispersed immediately after the ultrasonic treatment. Yes. In particular, it is confirmed that the dispersibility of the dispersion (Example 1-E) is excellent.
When 24 hours have passed immediately after the ultrasonic treatment, the dispersibility of the dispersions (Comparative Example 1-B), (Comparative Example 1-C), and (Comparative Example 1-D) is lost, and precipitation of carbon nanotubes is observed. . On the other hand, the dispersibility of the dispersion (Example 1-E) is maintained.
Even when 5 days have passed immediately after the ultrasonic treatment, the dispersion (Example 1-E) maintains the same dispersibility as that immediately after the ultrasonic treatment.

Drying treatment The slurry-like carbon nanotube dispersion obtained above was stirred with a stirrer (180 ° C.) for 24 hours to be evaporated and dried to obtain a dried powder.
When this powder was added again to a solvent composed of 16 ml of ethanol and 4 ml of water and stirred, it was confirmed that a carbon nanotube dispersion having the same dispersibility as the first was obtained.

Production of nanocarbon material composite The above powder was mixed with a binder such as PTFE (polytetrafluoroethylene) and subjected to hot pressing (200 ° C., 10 tons) to obtain a molded body. This molded article exhibited remarkably excellent electrical characteristics with an electrical resistivity of 0.3 to 0.7 Ω · cm.

2 and 3 show a line drawing of an image obtained by photographing the surface of this molded body with a scanning electron microscope (manufactured by Hitachi High-Technologies Corporation, S-3000H). 2 is a line drawing of an image taken at a magnification of 15000 and FIG. 3 is an image taken at a magnification of 6000.
As shown in FIG. 2 and FIG. 3, it was found that the carbon nanotubes were dispersed without being aggregated in the molded body, and a structure was formed in which holes were formed in some places.

Preparation of carbon raw material powder (2-1)
Multi-walled carbon nanotubes (Nanocyl, NC7000 (average diameter 9.5 nm, average length 1.5 μm, specific surface area 250-300 m2 / g, carbon purity 90%)) 0.1 g and graphite nanoplatelets (thickness) Nanometer-scale scaly graphite powder (manufactured by TCNT) was mixed with 0.05 g to prepare a nanocarbon material powder.
(2-2)
Multi-walled carbon nanotubes (Nanocyl, NC7000 (average diameter 9.5 nm, average length 1.5 μm, specific surface area 250-300 m2 / g, carbon purity 90%)) 0.1 g and carbon black powder (CABOT, (BP2000) 0.05 g was mixed to prepare a nanocarbon material powder.
Preparation of Solvent Sodium dodecyl sulfate (0.05) was dissolved in 16 ml of ethanol and 4 ml of water to prepare a solvent.

Dispersion treatment The solution obtained by adding the powder of the above-mentioned nanocarbon material to the above-mentioned solvent is subjected to an ultrasonic homogenizer (Mitsui Electric Seiki Co., Ltd., model: UX-600, oscillation frequency 20 ± 1 KHz, maximum output 600 W) for 20 minutes. Ultrasonic was irradiated to obtain a carbon nanotube dispersion.

Comparative Example As a comparative example for Example 2 above, a carbon nanotube dispersion was prepared by the following two methods (two comparative examples in Example 1, (Comparative Example 1-A) and (Comparative Example 1-C)) The same).
(Comparative Example 2-A) A carbon nanotube dispersion (Comparative Example 2-C) obtained by adding 0.1 g of multi-walled carbon nanotubes (same as above) to 20 ml of water and subjecting to ultrasonic treatment in the same manner as described above (Comparative Example 2-C) (Same as above) Powder obtained by mixing 0.1 g and graphite nanoplatelet (same as above) 0.05 g is added to a solvent composed of 16 ml of ethanol and 4 ml of water, and the same ultrasonic treatment as above is performed. Carbon nanotube dispersion

Dispersibility Test Results Carbon nanotube dispersions according to the above comparative examples (Comparative Example 2-A) and (Comparative Example 2-C), and carbon according to Example 2 of the present invention (using the powder of the above 2-1) A nanotube dispersion liquid (Example 2-1-B) and a carbon nanotube dispersion liquid (Example 2-2D) according to Example 2 (using the powder of 2-2 above) of the present invention were prepared almost simultaneously. Then, it was stored in a storage container sealed and allowed to stand at room temperature, and the course of 6 days was observed. The observation results are shown in FIG.
In FIG. 4, when 6 days have passed immediately after the ultrasonic treatment, the dispersibility of the dispersion liquid (Comparative Example 2-A) and (Comparative Example 2-C) is lost, and precipitation of carbon nanotubes is observed. On the other hand, the dispersibility of the dispersions (Example 2-1-B) and (Example 2-2D) is maintained.

Preparation of carbon raw material powder 0.1 g of multi-walled carbon nanotube (Nanocyl, NC7000 (average diameter 9.5 nm, average length 1.5 μm, specific surface area 250-300 m 2 / g, carbon purity 90%)) and activated carbon 0.05 g of powder (made by UES Co., Ltd., KD-PWSP (average particle size 6 μm)) was mixed to prepare nanocarbon material powder.
Preparation of Solvent Sodium dodecyl sulfate (0.05 g) was dissolved in 16 ml of ethanol and 4 ml of water to prepare a solvent.

Dispersion treatment The solution obtained by adding the powder of the above-mentioned nanocarbon material to the above-mentioned solvent is subjected to an ultrasonic homogenizer (Mitsui Electric Seiki Co., Ltd., model: UX-600, oscillation frequency 20 ± 1 KHz, maximum output 600 W) for 20 minutes. Ultrasonic was irradiated to obtain a carbon nanotube dispersion.

Dispersibility Test Results A carbon nanotube dispersion (Example 3-E) according to Example 3 of the present invention was prepared, sealed and stored in a storage container, and allowed to stand at room temperature, and the progress of 6 days was observed. The observation results are shown in FIG.
In FIG. 5, the dispersibility of the dispersion (Example 3-E) is maintained at the time when 6 days have passed immediately after the ultrasonic treatment.
The dispersion (Example 2-2D) shown in FIG. 5 is the same as the dispersion (Example 2-2D) in Example 2.

≪Instead of ultrasonic treatment, the rotating blades of honeycomb structure are rotated and stirred≫
Dispersion technology by ultrasonic treatment is suitable for small lot production, but may not be suitable for mass production technology. Therefore, we decided to try a meandering channel structure stirring process as a dispersion technique that could withstand mass production.
As described above, the meandering channel structure stirring process refers to a process in which a rotating blade or a disk-shaped stirring body having a structure for forming a meandering channel is rotated by a motor and stirred.

  As an example of a rotating blade or disk-shaped stirring body having a structure for forming a meandering flow path, use Lamond Stirrer (registered trademark) RS050A manufactured by Nanocus Co., Ltd. in Kitakyushu City, Kitakyushu City, Fukuoka Prefecture Can do. RS050A is composed of a disk portion and a shaft mounting portion connected to the center portion thereof. The disk portion has a plurality of chambers having a honeycomb structure inside thereof, and has a portion for sucking and discharging a fluid such as water, and the fluid passes through the plurality of chambers between the suction and the discharge. Thus, the fluid passes through the meandering flow path. Thus, it has a structure in which a meandering flow path is formed by a plurality of small chambers.

  RS050A weighs 82 grams and consists of a cast stainless steel called SCS14. The disk-shaped part has a diameter of 48 millimeters and a thickness of 7, 5 millimeters. By attaching a shaft to the shaft attachment portion and rotating it with a motor, fluid is sucked at the central portion of the disk-shaped portion and fluid is discharged at the peripheral portion of the disk.

Preparation of carbon raw material powder 0.1 g of multi-walled carbon nanotube (Nanocyl, NC7000 (average diameter 9.5 nm, average length 1.5 μm, specific surface area 250-300 m 2 / g, carbon purity 90%)) and graphite・ Nanoplatelet (scale-scale graphite powder of nanometer order; manufactured by TCNT) and carbon black powder (CABOT, BP2000) 0.05 g are mixed to obtain a powder of nanocarbon material Adjusted.
Preparation of Solvent Sodium dodecyl sulfate (0.05 g) was dissolved in 16 ml of ethanol and 4 ml of water to prepare a solvent.

Dispersion treatment A solution obtained by adding the powder of the above-mentioned nanocarbon material to the above-mentioned solvent was stirred at 2000 rpm for 15 minutes using a meandering channel structure stirring blade (manufactured by Nanocus Co., Ltd., model: RS050A). A dispersion was obtained.

Comparative Example As a comparative example with respect to Example 4, a carbon nanotube dispersion was prepared by the following four methods.
(Comparative Example 4-F) A carbon nanotube dispersion (Comparative Example 4-G) obtained by adding 0.1 g of multi-walled carbon nanotubes (same as above) to 20 ml of water and subjecting the same meandering channel structure stirring treatment to the above. A mixed powder of 0.1 g of carbon nanotubes (same as above) and 0.05 g of carbon black powder (same as above) is added to a solvent composed of 16 ml of ethanol and 4 ml of water, and the same meandering channel structure stirring treatment as above. A carbon nanotube dispersion (Comparative Example 4-H) obtained by performing the above was mixed with 0.1 g of multi-walled carbon nanotubes (same as above) and 0.05 g of graphite nanoplatelet (same as above) with 16 ml of ethanol. A carbon nanotube dispersion (Comparative Example 4-I) obtained by adding to a solvent consisting of 4 ml of water and subjecting to ultrasonic treatment in the same manner as described above. Powder obtained by mixing 0.1 g of nanotubes (same as above), 0.05 g of carbon black powder (same as above) and 0.05 g of graphite nanoplatelet (same as above) in a solvent composed of 16 ml of ethanol and 4 ml of water. Carbon nanotube dispersion obtained by adding and sonicating the same as above

Test results of dispersibility The carbon nanotube dispersion liquid (Comparative Example 4-F), (Comparative Example 4-G), (Comparative Example 4-H), (Comparative Example 4-I) according to the above comparative examples, and A carbon nanotube dispersion (Example 4-J) according to Example 4 was prepared almost simultaneously, sealed and stored in a storage container, and allowed to stand at room temperature, and the course of 5 days was observed. The observation results are shown in FIG.
In FIG. 6, the dispersion liquid (Comparative Example 4-G), (Comparative Example 4-H), (Comparative Example 4-I), and (Example 4-J) are moderate at the time immediately after the meandering channel structure stirring treatment. Is distributed. In particular, it is confirmed that the dispersibility of the dispersion liquid (4-J) is excellent.
When 24 hours have passed immediately after the meandering channel structure stirring treatment, the dispersibility of the dispersions (Comparative Example 4-G), (Comparative Example 4-H), and (Comparative Example 4-I) is lost, and the carbon nanotubes precipitate. Is seen. On the other hand, the dispersibility of the dispersion (Example 4-J) is maintained.
Even when 5 days have passed immediately after the meandering channel structure stirring treatment, the dispersion (Example 4-J) maintains the same dispersibility as that immediately after the meandering channel structure stirring treatment.

Drying treatment The slurry-like carbon nanotube dispersion obtained above was stirred with a stirrer (180 ° C.) for 24 hours to be evaporated and dried to obtain a dried powder.
When this powder was added again to a solvent composed of 16 ml of ethanol and 4 ml of water and stirred, it was confirmed that a carbon nanotube dispersion having the same dispersibility as the first was obtained.

Production of nanocarbon material composite The above powder was mixed with a binder such as PTFE (polytetrafluoroethylene) and subjected to hot pressing (200 ° C., 10 tons) to obtain a molded body. This molded article exhibited remarkably excellent electrical characteristics with an electrical resistivity of 0.3 to 0.7 Ω · cm.

  When the surface of this compact was observed using a scanning electron microscope (S-3000H, manufactured by Hitachi High-Technologies Corporation), carbon nanotubes were found in the compact as in Example 1 (FIGS. 2 and 3). It was found that the structure was dispersed without agglomeration, and pores were formed in some places.

Preparation of carbon raw material powder (5-1)
Multi-walled carbon nanotubes (Nanocyl, NC7000 (average diameter 9.5 nm, average length 1.5 μm, specific surface area 250-300 m2 / g, carbon purity 90%)) 0.1 g and graphite nanoplatelets (thickness) Nanometer-scale scaly graphite powder (manufactured by TCNT) was mixed with 0.05 g to prepare a nanocarbon material powder.
(5-2)
Multi-walled carbon nanotubes (Nanocyl, NC7000 (average diameter 9.5 nm, average length 1.5 μm, specific surface area 250-300 m2 / g, carbon purity 90%)) 0.1 g and carbon black powder (CABOT, (BP2000) 0.05 g was mixed to prepare a nanocarbon material powder.
Preparation of Solvent Sodium dodecyl sulfate (0.05) was dissolved in 16 ml of ethanol and 4 ml of water to prepare a solvent.

Dispersion treatment The solution obtained by adding the powder of the nanocarbon material to the solvent is subjected to a meandering channel structure stirring process at 2000 rpm for 15 minutes using a meandering channel structure stirrer (manufactured by Nanocus Co., Ltd., model: RS050A). Thus, a carbon nanotube dispersion was obtained.

Comparative Example As a comparative example for Example 5 above, a carbon nanotube dispersion was prepared by the following two methods (two comparative examples in Example 4, (Comparative Example 4-F) and (Comparative Example 4-H)). The same).
(Comparative Example 5-F) A carbon nanotube dispersion (Comparative Example 5-H) obtained by adding 0.1 g of multi-walled carbon nanotubes (same as above) to 20 ml of water and subjecting the same meandering channel structure stirring treatment to the above. A powder comprising a mixture of 0.1 g of carbon nanotubes (same as above) and 0.05 g of graphite nanoplatelets (same as above) is added to a solvent composed of 16 ml of ethanol and 4 ml of water, and the same meandering channel structure as above. Carbon nanotube dispersion obtained by stirring treatment

Dispersibility test results Carbon nanotube dispersions according to the above comparative examples (Comparative Example 5-F) and (Comparative Example 5-H), and carbon according to Example 5 of the present invention (using the powder of the above 5-1) A nanotube dispersion (Example 5-1-G) and a carbon nanotube dispersion (Example 5-1-I) according to Example 5 of the present invention (using the powder of 5-2 above) were prepared almost simultaneously. Then, it was stored in a storage container sealed and allowed to stand at room temperature, and the course of 6 days was observed. The observation results are shown in FIG.
In FIG. 7, when 6 days have passed immediately after the meandering channel stirring treatment, the dispersibility of the dispersion (Comparative Example 5-F) and (Comparative Example 5-H) is lost, and precipitation of the carbon nanotubes is observed. On the other hand, the dispersibility of the dispersions (Example 5-1-G) and (Example 5-2-I) is maintained.

Preparation of carbon raw material powder 0.1 g of multi-walled carbon nanotube (Nanocyl, NC7000 (average diameter 9.5 nm, average length 1.5 μm, specific surface area 250-300 m 2 / g, carbon purity 90%)) and activated carbon 0.05 g of powder (made by UES Co., Ltd., KD-PWSP (average particle size 6 μm)) was mixed to prepare nanocarbon material powder.
Preparation of Solvent Sodium dodecyl sulfate (0.05 g) was dissolved in 16 ml of ethanol and 4 ml of water to prepare a solvent.

Dispersion treatment The solution obtained by adding the powder of the nanocarbon material to the solvent is subjected to a meandering channel structure stirring process at 2000 rpm for 15 minutes using a meandering channel structure stirrer (manufactured by Nanocus Co., Ltd., model: RS050A). Thus, a carbon nanotube dispersion was obtained.

Dispersibility Test Results A carbon nanotube dispersion (Example 6-J) according to Example 6 of the present invention was prepared, sealed and stored in a storage container, and allowed to stand at room temperature, and the progress of 6 days was observed. The observation results are shown in FIG.
In FIG. 8, the dispersibility of the dispersion (Example 6-J) is maintained at the time when 6 days have passed immediately after the meandering flow path stirring process.
The dispersion liquid (Example 5-2I) shown in FIG. 8 is the same as the dispersion liquid (Example 5-2I) in Example 5.

FIG. 9 is a table listing examples and comparative examples. In FIG. 9, ◯ indicates that it is dispersed. X shows that it is not disperse | distributing and precipitation is seen.
The sodium dodecyl sulfate described above is a typical anionic surfactant. Similar results can be expected using other anionic or nonionic surfactants.
Ethanol is a typical example of a lower alcohol. Similar results can be expected using other lower alcohols.
Production of the nanocarbon material composite was performed using the powder obtained in Example 1-E and Example 4-J described above. Example 2-1B, which is another example, was performed. Preparation of nanocarbon material composite using powder obtained in Example 2-2D, Example 3-E, Example 5-1-G, Example 5-2I, and Example 6-E Even if it performs, it can be expected that a nanocarbon material composite having the same electrical resistivity and well dispersed carbon nanotubes can be obtained.

  The nanocarbon material dispersion method, the nanocarbon material dispersion, and the nanocarbon material composite of the present invention have been described above with specific embodiments, but the present invention is not limited thereto. . A person skilled in the art can make various changes and improvements to the raw materials, reagents, processing conditions, processing procedures, measurement conditions, and measurement methods without departing from the scope of the present invention.

  The nanocarbon material dispersion method, nanocarbon material dispersion, and nanocarbon material composite of the present invention can be used in many industries including inorganic chemistry, organic chemistry, and metal science.

Claims (15)

In a solvent in which an anionic surfactant or a nonionic surfactant having a weight ratio of 0.01 to 10% is added to an aqueous solution containing 10 to 100% by weight of a lower alcohol,
For a solution obtained by adding a powder in which a carbon material having an average particle diameter of 10 nm to 10 μm with a weight ratio of 1 to 30% is added to a carbon nanotube,
A method for dispersing a nanocarbon material, in which dispersion treatment is performed by ultrasonic treatment or a meandering channel structure stirring treatment.   The method for dispersing a nanocarbon material according to claim 1, wherein the carbon material includes one or more of graphene, carbon black, and activated carbon.   The nanocarbon according to claim 1 or 2, wherein the carbon material includes one or more of carbon nanofibers, fullerenes, carbon nanohorns, carbon microcoils, diamond-like carbon, and carbon nanocrystals. Material dispersion method.   The lower alcohol includes one or more of methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol, ethylene glycol, diethylene glycol, propylene glycol, and glycerin. The method for dispersing a nanocarbon material according to any one of the above.   The anionic surfactant or nonionic surfactant includes one or more of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, triethanolamine lauryl sulfate, and dodecyl itaconate. The method for dispersing a nanocarbon material according to any one of claims 1 to 4. The method for dispersing a nanocarbon material according to any one of claims 1 to 5, wherein the carbon nanotube is a multi-walled carbon nanotube.   The method for dispersing a nanocarbon material according to any one of claims 1 to 6, wherein the carbon material having a weight ratio of 10 to 20% is mixed with the carbon nanotube. In a solvent in which an anionic surfactant or a nonionic surfactant having a weight ratio of 0.01 to 10% is added to an aqueous solution containing 10 to 100% by weight of a lower alcohol,
For a solution obtained by adding a powder in which a carbon material having an average particle diameter of 10 nm to 10 μm with a weight ratio of 1 to 30% is added to a carbon nanotube,
A dispersion of a nanocarbon material obtained by performing a dispersion treatment by ultrasonic treatment or a meandering channel structure stirring treatment.   The said carbon material contains 1 type, or 2 or more types among graphene, carbon black, activated carbon, The dispersion liquid of the nano carbon material of Claim 8 characterized by the above-mentioned.   The nanocarbon according to claim 8 or 9, wherein the carbon material includes one or more of carbon nanofibers, fullerenes, carbon nanohorns, carbon microcoils, diamond-like carbon, and carbon nanocrystals. Material dispersion.   11. The lower alcohol includes one or more of methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol, ethylene glycol, diethylene glycol, propylene glycol, and glycerin. A dispersion of the nanocarbon material according to any one of the above.   The anionic surfactant or nonionic surfactant includes one or more of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, triethanolamine lauryl sulfate, and dodecyl itaconate. The dispersion liquid of the nanocarbon material according to any one of claims 8 to 11. The dispersion of nanocarbon material according to any one of claims 8 to 12, wherein the carbon nanotube is a multi-walled carbon nanotube.   14. The nanocarbon material dispersion liquid according to claim 8, wherein the carbon material is mixed with the carbon nanotubes in a weight ratio of 10 to 20%.   A nanocarbon material composite comprising a powder obtained by drying the dispersion of the nanocarbon material according to any one of claims 8 to 13, and a resin material or a metal material.

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