JP2013040262A - Drag reduction agent and method of manufacturing drag reduction agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drag reduction agent in which the addition of counter ions that has been necessary and indispensable in a surfactant based drag reduction agent is unnecessary, thereby, the introduction is simple, and a material that self-gathers by intermolecular interaction is used, thereby, the deterioration of a long chain structure by shearing force is not generated.SOLUTION: The drag reduction agent in which the tube frictional resistance of liquid that flows in a tube is decreased includes an organic nanotube uniformly dispersed in the liquid and forming a network structure. Such a drag reduction agent is made by that the liquid that is added with the organic nanotube is heated to be higher than the liquid-crystal phase transition temperature of the organic nanotube, and then is cooled to be lower than the liquid-crystal phase transition temperature.

Description

  The present invention relates to a resistance reducing agent for reducing the frictional resistance of a liquid in a pipe and a method for producing the same.

  Air conditioning is indispensable to public facilities such as factories and buildings, and closed circulation type fluid transportation systems are used for these. The piping of such a closed circulation type fluid transportation system extends over a long distance, and the resistance in the tube applied to the fluid flowing in the piping increases, so that a large fluid transportation power is required and the equipment cost of the fluid transportation system is enormous. become.

  On the other hand, in the fluid flowing in the pipe, frictional resistance that occurs at the boundary between the fluid and the pipe wall, and accompanying turbulent flow, etc. are generated, and the force against the flow acts on the fluid in the pipe. It is known that by adding a small amount of a specific substance to the pipe, the flow of the fluid in the pipe becomes smoother or the drag against the fluid in the pipe can be reduced. Substances having such an action are referred to in the art as “flow promoters”, “efficacy reducing agents”, “friction resistance reducing agents”, “DR agents”, etc. (in the present specification, these are referred to as “ Collectively referred to as “resistance reducing agent”).

  Therefore, in order to reduce the equipment cost of the fluid transportation system, it has been proposed to use a resistance reducing agent as a technique for reducing the power of fluid transportation by promoting a reduction in resistance of the flow in the pipe. Such proposals include a resistance reduction method using a surfactant and a resistance reduction method using a polymer agent. Examples of these known techniques include those described in the following three (Patent Documents 1 to 3).

  Patent Document 1 and Patent Document 2 describe a resistance reduction method using a surfactant-based resistance reducing agent. “Surfactant” means a substance having both a hydrophilic group having a high affinity for water and a lipophilic group (hydrophobic group) having a high affinity for oil, such as soap molecules. The surfactant-based resistance reducing agent forms rod-like micelles in the flow in the tube by adding a counter ion. Here, the “micelle” is a colloidal particle in which molecules having a hydrophilic group and a lipophilic group are gathered, and a thing in which these are gathered in a rod shape is called a rod-like micelle. The surfactant having a resistance reducing effect is in the state of rod-like micelles in the flow in the tube, and these rod-like micelles are connected and entangled to form a network structure of rod-like micelles. By forming this network structure, the turbulent flow structure is suppressed, and the flow is laminarized to exert a resistance reduction effect.

  What is important here is that any surfactant is not effective in reducing resistance, and the inclusion of a surfactant does not reduce the viscosity of the fluid in the tube and reduce the resistance. . That is, any surfactant is not effective in reducing the resistance, and in order to obtain the resistance reducing effect, a rod-like micelle must be formed to form a long chain network. In addition, the addition of a surfactant does not reduce the viscosity of the fluid in the tube and the resistance does not decrease, but the addition of a surfactant increases the viscosity of the fluid, and the original increase in the resistance. Forms a network structure constituted by rod-like micelles, and as a result of suppressing the turbulent flow structure, the resistance is relatively reduced.

  Since the surfactant molecules form micelles by self-assembly, they have the property of self-repairing even when the shearing force due to the frictional force with the tube wall acts on rod-like micelles in the fluid and the network structure is destroyed. That is, the surfactant-based resistance reducing agent has an advantage that the resistance reducing effect is not deteriorated by the shearing force even if time passes.

  Patent Document 3 describes a resistance reduction method using a polymer resistance reducing agent. “Polymer” means a molecule formed by covalent bonding of a large number of atoms. Some of these polymers have the property of being able to be connected, and in the flow in the pipe, they are connected in a long chain to form a network structure, thereby suppressing the turbulent flow structure and layering the flow. By flowing, the resistance is reduced.

  Unlike a surfactant molecule, a polymer has a long chain shape from the beginning, so there is no need to inject another substance such as a counter ion. It has the advantage that it can be introduced more easily than the agent resistance reducing agent.

JP 2002-080820 A JP 2004-323814 A JP 2000-136396 A

  However, each of the above-described known techniques has problems.

  As described above, the surfactant-based resistance reducing agent described in Patent Document 1 and Patent Document 2 forms a rod-like micelle by adding a counter ion, and these are connected to form a network structure. The resistance reduction effect is exhibited. That is, the addition of counter ions is indispensable for exhibiting the resistance reduction effect. Moreover, if the addition amount of this counter ion is not appropriate, a rod-like micelle cannot be formed and a resistance reduction effect cannot be exhibited. Therefore, the concentration of the counter ion must be an appropriate amount, and precise adjustment is required for introduction, and precision such as periodic confirmation and maintenance of the amount of surfactant and counter ion in the fluid is required. Has the problem of requiring careful adjustment. For this reason, there is a problem that it is difficult to spread. Therefore, with the surfactant-based resistance reducing agent, it becomes a problem to simplify introduction and further reduce costs for maintenance and the like.

  Further, unlike the surfactant resistance reducing agent, the polymer resistance reducing agent described in Patent Document 3 does not have a self-assembling property. For this reason, the long chain structure of the polymer is gradually destroyed under the influence of shear stress due to friction with the wall surface generated in the flow in the pipe. For this reason, the polymer resistance reducing agent has a problem that the resistance reduction effect decreases with time. If the resistance reduction effect decreases with the passage of time, restrictions such as being unusable in a closed circulation system arise. Therefore, in the polymer-based resistance reducing agent, it becomes a problem to prevent the resistance reducing effect with time.

  Therefore, the object of the present invention is to solve the problems existing in the prior art, eliminate the need for the addition of a counter ion, which is indispensable for surfactant-based resistance reducing agents, is easy to introduce, and is self-induced by intermolecular interaction. An object of the present invention is to provide a resistance reducing agent that does not cause deterioration of a long chain structure due to a shearing force by using a substance having an aggregation property.

  In view of the above-described object, the present invention is a resistance reducing agent for reducing the pipe friction resistance of a liquid flowing in a pipe, and the resistance reduction includes an organic nanotube that is uniformly dispersed in the liquid and forms a network structure. Provide the agent.

  The above-mentioned resistance reducing agent uses organic nanotubes, which are highly hydrophilic, nanometer-scale tubular materials, and these organic nanotubes are uniformly dispersed in a liquid and form a network structure. For this reason, the turbulent flow which generate | occur | produces in the liquid in a pipe | tube is suppressed, and the pipe | tube friction resistance of the liquid in a pipe | tube is reduced. Organic nanotubes are aggregated by an intermolecular interaction to form a network structure. Therefore, unlike a surfactant resistance reducing agent, a network structure can be formed without injecting counter ions, and precise adjustment of the concentration of counter ions is unnecessary, and introduction, maintenance, management, etc. are easy. Unlike polymer resistance reducing agents, even if the network structure is destroyed by shearing force, it can be reassembled by intermolecular interaction, and the resistance reduction effect does not decrease over time. Furthermore, organic nanotubes are substances that are decomposed by microorganisms present in activated sludge, and have a low environmental load even when released into the natural environment.

  The organic nanotube is preferably a glucose-based organic nanotube, and more preferably an organic nanotube formed from a glycolipid derivative in which glucose and oleic acid are linked via an amino bond.

  The concentration of the organic nanotube is preferably 1000 ppm or more when added to the liquid in the tube.

  For example, the organic nanotube can be uniformly dispersed in the liquid and a network structure can be formed by cooling the liquid to which the organic nanotube has been added after heating the liquid to the liquid crystal phase transition temperature of the organic nanotube or higher.

  The present invention also relates to a method of manufacturing a resistance reducing agent for reducing pipe frictional resistance of a liquid flowing in a pipe, the step of adding organic nanotubes to the liquid, and the liquid added with the organic nanotubes to the organic Heating above the liquid crystal phase transition temperature of the nanotubes, dissolving the organic nanotubes in the liquid; cooling the liquid in which the organic nanotubes are dissolved to below the liquid crystal phase transition temperature of the organic nanotubes; and And a step of forming a network structure of the organic nanotubes in a liquid.

  The organic nanotube is preferably a glucose-based organic nanotube, and more preferably an organic nanotube formed from a glycolipid derivative in which glucose and oleic acid are linked via an amino bond.

  In the step of adding the organic nanotube to the liquid, the concentration of the organic nanotube is preferably 1000 ppm or more.

  According to the present invention, since organic nanotubes are uniformly dispersed in a liquid and form a network structure, turbulent flow generated in the liquid in the pipe can be suppressed, and the pipe frictional resistance can be reduced. In addition, unlike a surfactant-based resistance reducing agent, since there is no need for a counter ion, introduction and maintenance are easy. Therefore, it can be used for private use. Furthermore, unlike the polymer resistance reducing agent, even if the network structure is destroyed, it self-assembles to form the network structure again, so that the resistance reduction effect does not deteriorate over time. Therefore, it can be used for facilities where it is difficult to exchange liquids. In addition, since organic nanotubes are decomposed in nature, even if the liquid to which the resistance reducing agent according to the present invention is added is released into the environment, the load on nature is small.

It is the actual photograph and enlarged view of the organic nanotube used for this invention. It is a structural formula of the organic nanotube used for this invention. It is the figure which showed a mode that the water which added the organic nanotube was heated. It is the result of the microscope observation which shows the mode of the network structure when the density | concentration of an organic nanotube is changed. It is a schematic diagram which shows the structure of the circular pipe water channel used by the effect confirmation test of the resistance reducing agent. It is a schematic diagram which shows the structure of the test section of the circular pipe waterway shown by FIG. It is a figure which shows a test result when the density | concentration of an organic nanotube is 0 ppm. It is a figure which shows a test result when the density | concentration of an organic nanotube is 1000 ppm. It is a figure which shows a test result when the density | concentration of an organic nanotube is 1500 ppm. It is a figure which shows a test result when the density | concentration of an organic nanotube is 2000 ppm. It is a figure which shows a test result when the density | concentration of an organic nanotube is 3000 ppm.

  Hereinafter, embodiments of a resistance reducing agent and a method for producing the resistance reducing agent according to the present invention will be described with reference to the drawings.

  The resistance reducing agent according to the present invention contains at least organic nanotubes uniformly dispersed in a liquid and forming a network structure.

  The resistance reducing agent according to the present invention is applied to, for example, an air conditioner having a closed circulation system, and the refrigerant to which the resistance reducing agent is added is circulated in the cold solvent transport pipe and the radiator, thereby driving the energy saving closed circulation system. Realize the device. This makes it possible to transport fluids with low power, greatly reducing the power required for pumps, etc., and improving the efficiency of system devices for a wide range. However, there is no problem, and the maintenance cost can be greatly reduced.

  A typical closed circulation system suitable for application of the present invention circulates a liquid having a liquid temperature of 70 ° C. or less, preferably 50 ° C. or less, through a fluid transport pipe having a diameter of 5 to 1000 mm, preferably 10 to 500 mm. It is. When the diameter is smaller than the above range, the water supply capacity is insufficient, and it is difficult to transport a sufficient fluid. When the diameter is large, the piping cost is too high. In addition, when the liquid temperature does not satisfy the above conditions, the bond of the organic nanotubes is broken and a long-chain network structure is not formed. Therefore, the resistance of the fluid is not increased and the viscosity of the fluid only rises. It will increase and will no longer play its original role.

  The concentration of the organic nanotube added as a resistance reducing agent to the liquid in the fluid transport pipe is preferably 100 ppm or more, and more preferably 1000 ppm or more. If the concentration of organic nanotubes does not satisfy this condition, a sufficient long-chain network structure cannot be formed, so the resistance reduction effect cannot be expected. However, if this condition is satisfied, the resistance reduction effect is exhibited and the power in fluid transportation is reduced. Energy saving effect is obtained.

  In the present specification, the “resistance reducing agent” means a substance having a function capable of reducing pipe friction in the pipe flow. As known resistance reducing agents, surfactants or polymer agents are known, but in the present invention, organic nanotubes that do not belong to either are used as the resistance reducing agent.

  In this specification, “organic nanotube” means a hollow fibrous structure material formed by self-assembly of an amphiphilic molecule having a hydrophilic group and a lipophilic group by intermolecular force in a liquid. means.

  There are types of organic nanotubes depending on the components constituting them, but the organic nanotubes used in the present invention are highly dispersible in water and form a long-chain network structure in the liquid. . In this embodiment, a glycolipid derivative in which glucose and oleic acid (derived from olive oil) are linked via an amide bond is used, and the solid powder is heated and dissolved in an organic solvent. Glucose-based organic nanotubes produced by drying are used. FIG. 1 shows a photograph of the glucose organic nanotube powder used, and FIG. 2 shows the structural formula of its constituent molecules. In this embodiment, glucose-based organic nanotubes are used, but other types of organic nanotubes are used as long as they can be uniformly dispersed in the liquid and can form a network structure. It is also possible to do.

  Investigation of the degradation degree of the glucose-based organic nanotubes was conducted according to “Degradation test of chemical substances by microorganisms” defined in “Test method for new chemical substances”. Organic nanotubes 100 mg / L and activated sludge 20 mg / L were stirred in water at 25 ° C. for 28 days, and the degradability by microorganisms present in the activated sludge was evaluated. As a result, the organic nanotubes were completely decomposed in 28 days, and the result that there was no influence on the environment was obtained. That is, even if organic nanotubes are released into the environment, they can be said to be substances that do not affect the environment and have a low environmental load.

  Since organic nanotubes cannot be mass-produced, they are substances that require a great deal of cost to produce, and conventionally, only application methods using a small amount have been considered. However, since mass production has become possible, application to various fields is now being considered. Therefore, the present inventor has studied the use of organic nanotubes as a resistance reducing agent, and organic nanotubes have high affinity and are uniform fiber-like minute substances. Focusing on the fact that the hollow fiber structure of organic nanotubes can be considered to be similar to the shape of rod-like micelles, similar to active agents and polymer agents. It has been found that the formed organic nanotube exhibits a resistance reducing action. In addition, due to the nature of self-assembly of organic nanotubes and the use of organic nanotubes that form tubes from the beginning, problems with existing resistance reducers, such as the addition of other substances and the passage of time It has been found that problems such as a reduction in the resistance reduction effect can be eliminated.

  In the present embodiment, powdered organic nanotubes are used, added to a liquid, dispersed in the liquid and formed into a network structure, and used as a resistance reducing agent. However, since organic nanotubes in a powder state usually have a strong bundle of the same substances, they are not dispersed in the liquid simply by adding them to a liquid such as water. On the other hand, as described above, not only a surfactant resistance reducing agent and a polymer resistance reducing agent but also a long chain network that is uniformly dispersed in the liquid in the flow path in order to exert a resistance reducing effect. The structure must spread. That is, even if powdered organic nanotubes are added to the liquid, the resistance reduction effect cannot be obtained. Therefore, in order to obtain a resistance reduction effect using organic nanotubes, it is first necessary to uniformly disperse the organic nanotubes in a liquid such as water and further form a long chain network structure.

  In this embodiment, in order to disperse the organic nanotubes in the liquid and further form a long-chain network structure, attention is paid to the self-assembly property and liquid crystal layer transition temperature of the organic nanotubes. The liquid crystal layer transition temperature means a critical temperature at which an organic nanotube that is a solid phase changes to a liquid phase, and when the temperature is exceeded, the organic nanotube is dissolved in the liquid. Even in this state, the condition is satisfied from the viewpoint of dispersion, but since it does not have a long chain network structure, it cannot be used as a resistance reducing agent in this state. However, organic nanotubes have the property of self-assembly due to intermolecular interactions. Therefore, by lowering the liquid temperature from the state where the liquid crystal layer transition temperature is exceeded, the organic nanotube constituent molecules below the liquid crystal phase transition temperature are reassembled, and the organic nanotube constituent molecules can form a tube structure again. Further, the reassembled organic nanotubes are completely dissolved in water once, so that the bundle is weakened and can be uniformly dispersed in water.

  Hereinafter, a test result for confirming that the organic nanotubes in a powder state are uniformly dispersed in the liquid and forms a network structure by the above-described procedure and exhibits a resistance reduction effect will be described.

  FIG. 3 shows a state where organic nanotubes are added to water and the temperature is gradually increased from room temperature. Since the liquid crystal phase transition temperature of the organic nanotube was about 70 ° C., the temperature was raised to a little lower than 80 ° C. and the state was observed. Moreover, the organic nanotube density | concentration at this time was 1000 ppm. The upper left of the figure is at room temperature, the upper right is in the middle of heating, the lower left is after heating, and the lower right is after reversion to normal temperature.

  At room temperature, most of the organic nanotubes settled on the bottom without being dispersed in water. These represent the strength of the bundle without being dispersed in the water when stirred. Heating was gradually performed from this state to raise the temperature. By increasing the temperature, the organic nanotubes gradually disperse and become white and cloudy as seen in the figure. When the temperature was close to 60 ° C., the precipitate was almost gone. When the liquid crystal phase transition temperature was raised, the cloudiness began to disappear and a translucent solution was obtained. This is considered to be because the molecular structure of the organic nanotube was decomposed by raising the temperature above the liquid crystal phase transition temperature. When heating of the completely decomposed solution is stopped and the temperature is lowered below the liquid crystal layer transition temperature, white turbidity occurs again. This is because the organic nanotubes were reassembled by the intermolecular interaction due to being below the liquid crystal phase transition temperature, and the molecular structure of the organic nanotubes was reconfigured. Organic nanotubes have low water dispersibility in the powder state and strong bundling of the same material. In this way, once the temperature is raised above the liquid crystal phase transition temperature, the structure is decomposed and reconstituted to uniformly disperse. A solution can be made.

  In order to exert the resistance reduction effect, it is necessary not only to uniformly disperse the organic nanotubes in the liquid but also to form a long chain network structure. As the name suggests, organic nanotubes are nanometer-scale substances, so the structure cannot be confirmed with the naked eye. Therefore, in order to investigate the dispersed solution from a more microscopic viewpoint, observation was performed using a scanning electron microscope (FE-SEM). Thereby, it can be judged whether the organic nanotube aqueous solution which produced the long-chain network required for resistance reduction is produced | generated. In addition, this observation also confirms the self-assembly characteristics described in the previous section.

  FIG. 4 is a result of microscopic observation showing a state of the formed network structure when the concentration of the organic nanotube is changed. The observation was performed by changing the organic nanotube concentration to 500, 1000, 1500, and 3000 ppm, heating the powdered organic nanotube to the liquid crystal layer transition temperature or higher in the above-described procedure, and then cooling it. Since the organic nanotube once dissolved in the liquid is reconstituted and dispersed almost uniformly as a whole, it can be proved that the dispersion was accurately performed by the above procedure. In addition, it can be seen that there is a difference between the dispersed organic nanotubes depending on their concentrations. Looking at the result of 500 ppm, the connection between the organic nanotubes is not so much seen. However, it can be seen that by increasing the concentration to 1000 ppm and 1500 ppm, the organic nanotubes become longer and the connection becomes denser, and a network structure is generated. It can be seen that the network structure becomes excessively dense at 3000 ppm and the difference from 500 ppm is large.

  From these results, it is possible to disperse organic nanotubes in water according to the procedure described above, the self-assembly characteristic is true, and the organic nanotube aqueous solution starts to form a long-chain network structure from about 1000 ppm. I understand. Since the resistance reduction effect requires a network structure, it can be said that the organic nanotube concentration is preferably 1000 ppm or more for the resistance reduction effect.

  Next, the resistance reduction effect of the resistance reducing agent produced from the organic nanotube as described above is confirmed.

  FIG. 5 is a schematic diagram of a circular pipe channel used in the effect confirmation test of the resistance reducing agent. In this test, tap water was used as the liquid to which the resistance reducing agent was added. The water channel is composed of an acrylic pipe test section having an inner diameter of 10 mm, a flow control valve, a pump, and a joint for water injection. The total length is about 8 m and the capacity is 0.628 L. Details of the test section are shown in FIG. In order to measure the flow that has developed into sufficiently turbulent flow, the run section was 1 m, and the length of the test section that actually measured the differential pressure was 2 m. A differential pressure gauge is connected upstream and downstream of the test section to measure the differential pressure. At the same time, the flow rate and the water temperature are measured and converted to the tube friction coefficient and the Reynolds number, and the change of the tube friction coefficient with respect to the Reynolds number is investigated. The density | concentration of the organic nanotube to measure was 0 ppm, 1000 ppm, 1500 ppm, 2000 ppm, and 3000 ppm.

  The result of the experiment using a circular pipe channel is shown in FIGS. Each figure is accompanied by an electron microscope result corresponding to the concentration. For comparison of the experimental results, the Hagen-Poiseuille equation and the Blasius' formula, which are empirical formulas, are used. The Hagen-Poiseuille equation is a laminar flow equation, and the Blasius equation is a turbulent flow equation. This time, the results are organized with the Reynolds number on the horizontal axis and the pipe friction coefficient on the vertical axis, so if the measured value is below these empirical formulas, it can be judged that there is a resistance reduction effect. it can. The difference is calculated as a resistance reduction rate (DR).

  FIG. 7 shows test results when the concentration of organic nanotubes is 0 ppm, that is, when only tap water is passed. Thereby, the reliability of the experimental apparatus can be confirmed. Looking at the plotted points, it can be seen that almost everything is on the straight line obtained by the empirical formula. The distribution is 3.5 to -3.0% in terms of DR, and the average is -0.4%. Considering this result, it was judged that there was a resistance reduction effect when there was a minimum 4% resistance reduction.

  FIG. 8 shows the test results when the concentration of the organic nanotube is 1000 ppm. Actually, a measured value is changed by flowing an aqueous solution to which an organic nanotube is added as a resistance reducing agent. Values varied slightly, with a DR distribution of 6.5-5.7% and an average DR of 0.7%. Although it is difficult to judge that there is a resistance reduction effect at this point, it can be seen that a change has surely occurred due to the addition of the organic nanotube.

  FIG. 9 shows the test results when the concentration of the organic nanotube is 1500 ppm. It can be seen that the variation in the value calculated by increasing the concentration of the organic nanotubes becomes larger, and the distribution slightly moves to the resistance reduction side than in the case of FIG. The DR distribution is 8.1 to -4.4%, and the average DR is 2.1%. It can be seen that there is a change in the measured value by increasing the concentration of the organic nanotubes as compared with the case where the concentration of the organic nanotubes is low.

  FIG. 10 shows the test results when the concentration of the organic nanotube is 2000 ppm. What should be noted here is that all values were observed on the resistance reduction side. In the measurement so far, values on the resistance increasing side were sometimes calculated, but they disappeared, and the value rapidly moved to the resistance decreasing side. The DR distribution was 9.8 to 3.0%, and the average DR was 6.5%. The average value exceeded 4% as a reference, and the occurrence of the resistance reduction effect was clearly confirmed.

  FIG. 11 shows the test results when the concentration of the organic nanotube is 3000 ppm. It can be seen that the resistance reduction effect increases, and the DR distribution is 18 to 3.3%, and the average DR is 10%, and it can be determined that there is a resistance reduction effect as expected.

  From the results of the effect confirmation test, it can be said that when organic nanotubes are used as a resistance reducing agent, a quantitative increase in the resistance reducing effect can be confirmed up to 3000 ppm.

  As a result of observation of the above heating state, as a result of microscopic observation, as a result of a confirmation test of the resistance reduction effect, an organic nanotube added by adding an organic nanotube to a liquid is heated to a temperature higher than the liquid phase transition temperature and then cooled. It was proved that the bundles of each other can be unwound and dispersed almost uniformly in water. In addition, when the concentration of organic nanotubes is low, the network structure does not develop much, and the resistance reduction effect is low, but by forming the concentration of organic nanotubes in the liquid at 1000 ppm or more, a long chain network structure is formed to some extent densely. As a result, it has been found that it can be sufficiently used as a resistance reducing agent. Furthermore, it has been found that the resistance reduction effect is improved by increasing the concentration.

As mentioned above, although the resistance reducing agent by this invention and its manufacturing method were demonstrated with reference to embodiment shown in figure, this invention is not limited to embodiment. For example, in the embodiment, a powdered organic nanotube added to a liquid is heated to a liquid crystal layer transition temperature or higher and then cooled to uniformly disperse the organic nanotube in the liquid and form a network structure. However, the organic nanotubes may be uniformly dispersed in the liquid and a network structure may be formed by other methods. It is also possible to use organic nanotubes in a form other than powder.

Claims (9)

A resistance reducing agent for reducing the frictional resistance of the liquid flowing in the pipe,
A resistance-reducing agent comprising organic nanotubes uniformly dispersed in a liquid and having a network structure.   The resistance reducing agent according to claim 1, wherein the organic nanotube is a glucose-based organic nanotube.   The resistance reducing agent according to claim 2, wherein the glucose organic nanotube is an organic nanotube formed from a glycolipid derivative in which glucose and oleic acid are linked via an amino bond.   The resistance reducing agent according to any one of claims 1 to 3, wherein the concentration of the organic nanotube is 1000 ppm or more when added to the liquid in the tube.   The liquid to which the organic nanotube is added is heated to a temperature higher than a liquid crystal phase transition temperature of the organic nanotube and then cooled to uniformly disperse the organic nanotube in the liquid and form a network structure. Item 5. The resistance reducing agent according to any one of Items 4. A method for producing a resistance reducing agent for reducing the frictional resistance of a liquid flowing in a pipe,
Adding organic nanotubes to the liquid;
Heating the liquid added with the organic nanotubes to a temperature higher than a liquid crystal phase transition temperature of the organic nanotubes, and dissolving the organic nanotubes in the liquid;
Cooling the liquid in which the organic nanotubes are dissolved to a temperature equal to or lower than a liquid crystal phase transition temperature of the organic nanotubes, dispersing the organic nanotubes in the liquid and forming a network structure of the organic nanotubes;
A process for producing a resistance reducing agent comprising:   The method according to claim 6, wherein the organic nanotube is a glucose-based organic nanotube.   The method according to claim 7, wherein the glucose-based organic nanotube is an organic nanotube generated from a glycolipid derivative in which glucose and oleic acid are linked via an amino bond.   The resistance reducing agent according to any one of claims 6 to 8, wherein in the step of adding the organic nanotube to the liquid, the concentration of the organic nanotube is set to 1000 ppm or more.

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