JP2011214174A - Method for producing nanofiber, apparatus for producing nanofiber, and method for producing yarn comprising nanofiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a nanofiber by which the nanofiber can be produced in an extremely simple step without requiring a large-scale mechanism.SOLUTION: The method for producing the nanofiber includes: a first step of forming a state in which a polymer material solution is sandwiched between two sample adhesion plates (a first sample adhesion plate 120 and a second sample adhesion plate 130) wherein mutually opposite sample adhesion surfaces are adjacent; a second step of suddenly separating the two sample adhesion plates (the first sample adhesion plate 120 and second sample adhesion plate 130), thereby stretching the polymer material, and producing the nanofiber; and a third step of recovering the nanofiber kept in a state that the nanofiber is stretched between the two sample adhesion plates (the first sample adhesion plate 120 and second sample adhesion plate 130) in the order.

Description

  The present invention relates to a method for producing nanofibers, a device for producing nanofibers, and a method for producing “yarns composed of nanofibers”.

  Conventionally, as a nanofiber production method, a nanofiber production method (for example, see Patent Document 1) using a melt spinning method (melt blown spinning method) and a nanofiber using an electrospinning method (electrospinning spinning method) Manufacturing methods (see, for example, Patent Documents 2 to 4) are known. The method for producing nanofibers using the melt spinning method is to produce nanofibers by discharging a polymer melted from a thin nozzle together with a high-temperature air stream. Moreover, the manufacturing method of the nanofiber using the electrospinning method manufactures nanofiber by discharging a polymer solution from a nozzle in the state which applied the high voltage between the nozzle and the collector.

  For this reason, according to the manufacturing method of these nanofibers, an ultrafine nanofiber having an average diameter of about 1000 nm or less can be manufactured.

US Pat. No. 6,141,007 US Pat. No. 6,673,136 International Publication No. WO2009 / 153051 Pamphlet International Publication No. WO2009 / 034765 Pamphlet

  However, the nanofiber manufacturing method using the melt spinning method has a problem that a large-scale mechanism for discharging the molten polymer from a thin nozzle together with a high-temperature air flow is required. In addition, the nanofiber manufacturing method by the electrospinning method has a problem that a large-scale mechanism for discharging the polymer solution from the nozzle in a state where a high voltage is applied between the nozzle and the collector is necessary.

  Then, this invention aims at providing the manufacturing method of a nanofiber which can manufacture a nanofiber by a very simple process, and without requiring a large-scale mechanism, and the manufacturing apparatus of a nanofiber. To do. In addition, the present invention provides a method for producing a “yarn made of nanofibers” that can produce a “yarn made of nanofibers” by an extremely simple process and without requiring a large-scale mechanism. For the purpose.

[1] The method for producing nanofibers of the present invention includes a first step of forming a state in which a viscoelastic body is sandwiched between two sample attachment plates in a state where the sample attachment surfaces facing each other are close to each other; A second step of producing the nanofibers by stretching the viscoelastic body by abruptly separating the sample attachment plate; and a third step of collecting the nanofibers in a state of being stretched between the two sample attachment plates; In this order.

  For this reason, according to the method for producing nanofibers of the present invention, as will be apparent from the examples described later, it is extremely simple that only the two sample attachment plates with the viscoelastic body sandwiched therebetween are rapidly pulled apart. With this method, ultrafine nanofibers having an average diameter of 1000 nm or less can be produced. As a result, the nanofiber manufacturing method of the present invention is a nanofiber manufacturing method capable of manufacturing nanofibers in a very simple process and without requiring a large-scale mechanism.

  Further, according to the method for producing nanofibers of the present invention, as a result of producing the nanofibers by stretching the viscoelastic body in the direction of separating the sample attachment plate, the orientation and Nanofibers with high crystallinity and high strength can be produced.

[2] In the method for producing nanofibers of the present invention, it is preferable to repeat a plurality of elementary steps including the first to third steps in this order.

  By setting it as such a method, an ultrafine nanofiber can be manufactured with high productivity.

[3] In the method for producing nanofibers of the present invention, the first step is performed by attaching the sample through a viscoelastic body supply hole formed in advance on at least one of the two sample attachment plates. It is preferable to carry out by supplying the viscoelastic body between the two sample adhering plates in a state where the surfaces are close to each other.

  By adopting such a method, it is possible to relatively easily form a state in which a viscoelastic body is sandwiched between two sample attachment plates.

[4] In the method for producing nanofibers of the present invention, the viscoelasticity of the first step is performed from the outer periphery of two sample attachment plates between the two sample attachment plates in a state where the sample attachment surfaces are close to each other. It is preferably performed by soaking the body.

  Even with this method, it is possible to relatively easily form a state in which the viscoelastic body is sandwiched between the two sample attachment plates.

[5] In the nanofiber manufacturing method of the present invention, the first step is directed toward at least one sample attachment surface of the two sample attachment plates in a state where the sample attachment surface is separated by a predetermined amount. After discharging the viscoelastic body from the nozzle, it is preferable that the two sample attachment surfaces be brought close to each other.

  Even with this method, it is possible to relatively easily form a state in which the viscoelastic body is sandwiched between the two sample attachment plates.

[6] In the nanofiber manufacturing method of the present invention, it is preferable that the first step is performed in a state where the sample attachment surface is heated to a predetermined temperature.

  By setting it as such a method, since the viscosity of a viscoelastic body can be made low, it becomes possible to manufacture a much finer nanofiber.

  When a polymer material solution containing a polymer material is used as the viscoelastic body, the solvent of the polymer material solution is removed when the polymer material is stretched by rapidly separating the two sample attachment plates. Thus, it is possible to produce high-quality nanofibers with extremely low solvent content. In addition, since the polymer material can be stretched at a temperature higher than the glass transition temperature, high-quality nanofibers can be produced.

[7] In the nanofiber manufacturing method of the present invention, it is preferable that the second step is performed by moving at least one of the two sample attachment plates by extension or compression of a spring.

  By adopting such a method, the operation of rapidly separating the two sample attachment plates can be performed at high speed. In addition to a mechanical spring spring, a pneumatic spring (air cylinder), a hydraulic spring, or the like can be used as the spring.

[8] In the method for producing nanofibers of the present invention, the second step is preferably performed by moving at least one of the two sample attachment plates with a motor according to a predetermined procedure.

  By adopting such a method, the operation of rapidly separating the two sample attachment plates can be performed at high speed and with high accuracy.

[9] In the method for producing nanofibers of the present invention, in the first step, at least one of the two sample attachment plates is moved by a motor according to a predetermined procedure, thereby the two sample attachment surfaces. Is preferably in the range of 0.01 mm to 0.5 mm.

By adopting such a method, it becomes possible to accurately control the layer thickness of the viscoelastic body sandwiched between two sample attachment plates in the state where the sample attachment surfaces facing each other are close to each other.
Here, the height of the protrusion for regulating the distance between the sample adhering surfaces is set within the range of 0.01 mm to 0.5 mm for the following reason. That is, when the height of the protrusion for regulating the distance between the adhering surfaces of the sample is higher than 0.5 mm, it may be difficult to produce ultrafine polymer nanofibers because the layer thickness of the viscoelastic body is too thick. Because there is. On the other hand, when the height of the protrusion for regulating the distance between the adhering surfaces of the samples is lower than 0.01 mm, the layer thickness of the viscoelastic body is too thin, and it is possible to manufacture ultrafine polymer nanofibers with high productivity. This is because it may be difficult.

[10] In the method for producing nanofibers of the present invention, for the sample adhering surface interval regulation, the height of at least one sample adhering surface of the sample adhering plates is in the range of 0.01 mm to 0.5 mm. It is preferable that a plurality of protrusions are formed.

  Even with such a method, it is possible to accurately control the layer thickness of the viscoelastic body sandwiched between two sample attachment plates in a state where the sample attachment surfaces facing each other are close to each other. The height of the protrusion for regulating the sample adhering surface interval is set within the range of 0.01 mm to 0.5 mm for the same reason as described above.

[11] In the nanofiber manufacturing method of the present invention, in the third step, the nanofiber recovery plate for recovering the nanofibers is arranged in a direction perpendicular to the direction in which the two sample attachment plates are separated from each other. It is preferable to collect an assembly of nanofibers as the nanofibers by moving them.

  By setting it as such a method, the nanofiber in the state extended | stretched between two sample adhesion plates can be collect | recovered as an aggregate | assembly of a nanofiber.

[12] In the method for producing nanofibers of the present invention, the nanofiber recovery plate preferably has a recovery surface formed on a rough surface.

  By adopting such a method, the nanofibers can be easily separated from the nanofiber recovery plate.

[13] In the method for producing nanofibers of the present invention, it is preferable to separate the nanofibers from the nanofiber collection plate by suction force when collecting the nanofibers.

  By adopting such a method, the nanofibers can be easily separated from the nanofiber recovery plate.

[14] In the method for producing nanofibers of the present invention, each time the third step is performed, on the endless belt that moves intermittently or continuously along the direction in which the two sample attachment plates are separated. It is preferable to collect a long nanofiber aggregate along the stretching axis of the nanofiber as the nanofiber by placing the collected nanofiber aggregate.

  By setting it as such a method, the nanofiber in the state extended | stretched between two sample adhesion plates can be collect | recovered as an aggregate | assembly of long nanofiber along the extending | stretching axis | shaft of a nanofiber.

[15] In the method for producing nanofibers of the present invention, each time the third step is performed, on the rotating drum that rotates intermittently or continuously around the axis in the direction in which the two sample attachment plates are separated. In addition, it is preferable to collect a long nanofiber aggregate along the direction perpendicular to the stretching axis of the nanofiber as the nanofiber by placing the collected nanofiber aggregate.

  By adopting such a method, the nanofibers stretched between the two sample attachment plates can be collected as a long nanofiber aggregate along the direction perpendicular to the nanofiber stretching axis. it can.

[16] In the method for producing nanofibers of the present invention, at least two sets of the two sample attachment plates are prepared, and at least two sets of the “two sample attachment plates” are separated from each other. The nanofiber layers having different stretching axes are sequentially laminated by sequentially performing the elementary steps including the first step to the three steps on the at least two sets of “two sample attachment plates”. It is preferable to collect the aggregate of sheet-like nanofibers in the formed state.

  By setting it as such a method, the nanofiber in the state extended | stretched between two sample adhesion plates can be collect | recovered as an aggregate | assembly of a sheet-like nanofiber.

[17] In the nanofiber manufacturing method of the present invention, the viscoelastic body is preferably a polymer material solution containing a polymer material or a molten polymer material obtained by melting a polymer material.

  By setting it as such a method, it becomes possible to collect | recover polymeric nanofiber as a nanofiber.

  In this case, since a solvent (for example, cyclohexane) that cannot be used alone by the electrospinning method can be used, a type of nanofiber (for example, polypropylene) that is not easily manufactured by the nanofiber manufacturing method using the electrospinning method. It is also possible to produce nanofibers made of

[18] In the method for producing nanofibers of the present invention, the viscoelastic body is preferably a low molecular material solution containing a low molecular material or a molten low molecular material obtained by melting a low molecular material.

  By setting it as such a method, it becomes possible to collect | recover polymeric nanofiber as a nanofiber.

[19] In the method for producing a nanofiber of the present invention, the viscoelastic body is preferably a molten metal material obtained by melting a metal material.

  By setting it as such a method, it becomes possible to collect | recover metal nanofiber as a nanofiber.

[20] The nanofiber manufacturing apparatus of the present invention is a nanofiber manufacturing apparatus for carrying out the nanofiber manufacturing method of the present invention, and is installed on the base and on the base so as to face each other. Two sample attachment plates having a sample attachment surface, a viscoelastic body supply device for supplying a viscoelastic body between the two sample attachment plates, and stretching the viscoelastic body by rapidly separating the two sample attachment plates And a sample attachment plate separating device for producing nanofibers, and a nanofiber recovery device for recovering the nanofibers that are stretched between the two sample attachment plates.

  For this reason, according to the nanofiber manufacturing apparatus of the present invention, the nanofiber manufacturing method of the present invention can be carried out, so that it is an extremely simple process and does not require a large-scale mechanism. The nanofiber production apparatus is capable of producing nanofibers.

  In addition, according to the nanofiber manufacturing apparatus of the present invention, the nanofiber manufacturing method of the present invention can be carried out, so that high-strength nanofibers with good orientation and crystallinity can be manufactured. It becomes a manufacturing device of nanofiber.

[21] The method for producing a “yarn made of nanofibers” according to the present invention comprises passing the nanofibers produced by the method for producing nanofibers of the present invention through a twisting device to make a “yarn comprising nanofibers” from the nanofibers Is characterized by manufacturing

  By adopting such a method, it is possible to produce a “strength made of nanofibers” having a high degree of orientation and crystallinity in a very simple process and without requiring a large-scale mechanism. .

[22] The method for producing “the yarn comprising nanofibers” of the present invention comprises “the nanofiber” comprising producing “the yarn comprising nanofibers” using the nanofiber produced by the method for producing nanofibers of the present invention. In the third step, in the third step, at least one of the two sample attachment plates is rotated around an axis perpendicular to the sample attachment surface, and the “nano” It is characterized in that “threads made of fibers” are collected.

  By adopting such a method, it is possible to produce a high-strength “yarn made of nanofibers” with excellent orientation and crystallinity without requiring a large-scale mechanism in a very simple process. it can.

It is a figure shown in order to demonstrate the principle of the manufacturing method of the nanofiber of this invention. It is a figure shown in order to demonstrate the manufacturing apparatus 100 of the polymer nanofiber concerning Embodiment 1. FIG. FIG. 3 is a view for explaining a first sample attachment plate 120 in the first embodiment. FIG. 3 is a view for explaining a second sample attachment plate 130 in the first embodiment. It is a figure shown in order to demonstrate the manufacturing method of the nanofiber concerning Embodiment 1. FIG. It is a figure shown in order to demonstrate the manufacturing method of the nanofiber concerning Embodiment 1. FIG. It is a figure shown in order to demonstrate the viscoelastic body supply apparatus in the modification 1. FIG. It is a figure shown in order to demonstrate the viscoelastic body supply apparatus in the modification 2. FIG. It is a figure shown in order to demonstrate the sample adhesion board 136 in the modification 3. FIG. It is a figure shown in order to demonstrate operation | movement of the 2nd sample adhesion board 130 in the modification 4. FIG. It is a figure shown in order to demonstrate the manufacturing method of the nanofiber concerning Embodiment 2. FIG. FIG. 5 is a view for explaining a method for producing “a yarn made of nanofibers” according to Embodiment 2. It is a figure shown in order to demonstrate the manufacturing method of the nanofiber concerning Embodiment 3. It is a figure shown in order to demonstrate the manufacturing method of the nanofiber concerning Embodiment 4. It is a figure shown in order to demonstrate the manufacturing method of the nanofiber concerning Embodiment 4. FIG. 10 is a view for explaining a method of manufacturing “a yarn made of nanofibers” according to Embodiment 5. 2 is an optical micrograph of nanofibers produced in Example 1. 2 is a scanning electron micrograph of nanofibers produced in Example 1. FIG. 2 is an X-ray diffraction chart of nanofibers manufactured in Example 1. FIG. 2 is a scanning electron micrograph of nanofibers produced in Example 2. FIG. FIG. 3 is a scanning electron micrograph of “nanofiber yarn” produced in Example 2. FIG. 3 is a scanning electron micrograph of nanofibers produced in Example 3. FIG.

  Hereinafter, the manufacturing method of the nanofiber of the present invention, the manufacturing device of the nanofiber, and the manufacturing method of the “thread made of nanofiber” will be described based on the embodiments shown in the drawings.

  First, the principle of the method for producing nanofibers of the present invention will be described. FIG. 1 is a diagram shown for explaining the principle of the method for producing nanofibers of the present invention. FIG. 1A is a diagram illustrating a state in which the nanofiber 10 is manufactured using a thumb and an index finger, and FIG. 2A is a diagram illustrating a state in which the nanofiber 10 is manufactured using two petri dishes.

  As can be seen from FIG. 1, the nanofiber manufacturing method of the present invention has a state in which a viscoelastic body such as a polymer material solution containing a polymer material is sandwiched between two sample attachment plates such as a finger and a petri dish. Then, the nanofiber 10 is manufactured by stretching the viscoelastic body by abruptly separating two sample attachment plates such as a finger and a petri dish from this state.

  Therefore, according to the method for producing nanofibers of the present invention, as will be apparent from the examples described later, it is extremely simple that the two sample attachment plates in a state where the viscoelastic body is sandwiched between them are simply pulled apart. By the method, it is possible to produce ultrafine nanofibers 10 having an average diameter of 1000 nm or less. As a result, the nanofiber manufacturing method of the present invention is a nanofiber manufacturing method capable of manufacturing the nanofiber 10 with a very simple process and without requiring a large-scale mechanism.

[Embodiment 1]
1. Configuration of Nanofiber Manufacturing Device 100 First, the configuration of the nanofiber manufacturing device 100 according to Embodiment 1 will be described with reference to FIGS.

  FIG. 2 is a view for explaining the nanofiber manufacturing apparatus 100 according to the first embodiment. 2A is a front view of the nanofiber manufacturing apparatus 100, FIG. 2B is a top view of the nanofiber manufacturing apparatus 100, and FIG. 2C is A1- of FIG. 2B. It is A1 sectional drawing. In FIG. 2A, the nanofiber recovery device 160 and the nanofiber recovery tray 170 are not shown.

FIG. 3 is a view for explaining the first sample attachment plate 120 in the first embodiment. FIG. 3A is a side view of the first sample attachment plate 120, and FIG. 3B is a front view of the first sample attachment plate 120.
FIG. 4 is a view for explaining the second sample attachment plate 130 in the first embodiment. FIG. 4A is a front view of the second sample attachment plate 130, and FIG. 4B is a side view of the second sample attachment plate 130.

  As shown in FIG. 2, the nanofiber manufacturing apparatus 100 according to the first embodiment is installed on a base 110 and the base 110, and the sample attachment surfaces (the first sample attachment surface 122 and the second sample) facing each other. Between two sample attachment plates (first sample attachment plate 120 and second sample attachment plate 130) having attachment surfaces 132) and two sample attachment plates (first sample attachment plate 120 and second sample attachment plate 130). The viscoelastic body supply device 150 for supplying the viscoelastic body to the two and the two sample attachment plates (the first sample attachment plate 120 and the second sample attachment plate 130) are rapidly pulled apart to stretch the viscoelastic body to form nanofibers. 10 and the nanofiber recovery device 160 and the nanofiber recovery device 160 for recovering the nanofiber 10 that is stretched between the two sample attachment plates (the first sample attachment plate 120 and the second sample attachment plate 130). Fiber collection tray And a 170.

  As shown in FIG. 2, the first sample attaching plate 120 is fixed on the base 110 via the first base 114. Further, as shown in FIG. 3, the first sample attachment plate 120 has a first sample attachment surface 122 on the surface facing the second sample attachment plate 130. Further, as shown in FIG. 3, the first sample attachment plate 120 has viscoelasticity for supplying a viscoelastic body between two sample attachment plates (the first sample attachment plate 120 and the second sample attachment plate 130). A body supply hole 126 is provided. Further, as shown in FIG. 3, a heater 124 for heating the first sample attachment surface 122 to a predetermined temperature is installed on the back surface of the first sample attachment plate 120.

  As shown in FIG. 2, the second sample attachment plate 130 moves along the left-right direction in FIG. 1A inside the outer cylinder member 140 fixed on the base 110 via the second base 112. It is provided at the leading end portion (left end portion in FIG. 2A) of the possible inner cylinder member 136. A coil spring 142 is inserted into the inner cylinder member 136, the tip end portion of the coil spring 142 is fixed to the back side of the tip end portion of the inner cylinder member 136, and the rear end portion of the coil spring 142 is fixed to the outer cylinder member 140. . The inner cylinder member 136 can be moved in the left-right direction in FIG. 2 by a motor (not shown). As shown in FIG. 4, the second sample attachment plate 130 has a second sample attachment surface 132 on the surface facing the first sample attachment plate 120. Further, as shown in FIG. 4, a heater 134 for heating the second sample attachment surface 132 to a predetermined temperature is installed on the back surface of the second sample attachment plate 130.

  The viscoelastic body supply device 150 includes a raw material tank 151 that stores a viscoelastic body, a connection line 152 having one end connected to the raw material tank 151, and an electromagnetic valve 154 installed in the connection line 152. The other end side of the connection line 152 is connected to the viscoelastic body supply hole 126 of the first sample attachment plate 120.

  The nanofiber recovery device 160 is a nanofiber recovery plate 168 for recovering nanofibers, and the nanofiber recovery plate 168 is separated from the two sample attachment plates (the first sample attachment plate 120 and the second sample attachment plate 130). And a drive mechanism (motor 162, arm 164, and support portion 166) that moves in a direction perpendicular to the direction.

2. Nanofiber Manufacturing Method FIGS. 5 and 6 are diagrams for explaining the nanofiber manufacturing method according to the first embodiment. FIGS. 5A to 5D and FIGS. 6A to 6D are process diagrams. 5 (a) to 5 (d) and FIG. 6 (a) correspond to FIG. 2 (a), and FIGS. 6 (b) to 6 (d) correspond to FIG. 2 (c). It is a corresponding figure.

  The nanofiber manufacturing method according to Embodiment 1 uses a polymer material solution containing a polymer material as a viscoelastic body. As shown in FIGS. 5 and 6, the method for producing nanofibers according to the first embodiment 2 in a state where the sample attachment surfaces (the first sample attachment surface 122 and the second sample attachment surface 132) facing each other are close to each other. A first step of forming a state in which a polymer material solution as a viscoelastic body is sandwiched between two sample attachment plates (first sample attachment plate 120 and second sample attachment plate 130), and two sample attachment plates A second step of producing the nanofiber 10 by stretching the polymer material by abruptly separating the (first sample attachment plate 120 and the second sample attachment plate 130), and two sample attachment plates (first sample attachment plate) 120 and the third sample attaching plate 130), and a third step of recovering the nanofibers 10 in a state of being stretched in this order.

(1) First Step In the first step, two sample attachment plates (first sample attachment plate 120) in a state where the sample attachment surfaces (first sample attachment surface 122 and second sample attachment surface 132) facing each other are brought close to each other. And the second sample attaching plate 130) are steps for forming a state in which the polymer material solution is sandwiched (see FIGS. 5A to 5D).

  In the first step, the sample attachment surfaces (the first sample attachment surface 122 and the second sample attachment surface 132) are passed through the viscoelastic body supply holes 126 formed in advance on the sample attachment surface 122 of the first sample attachment plate 120. This is performed by supplying a polymer material solution between two sample adhering plates (first sample adhering plate 120 and second sample adhering plate 130) in a state of being close to each other.

  The supply of the polymer material solution can be performed by opening and closing the electromagnetic valve 154. A pressurizing device that applies pressure to the polymer material solution may be disposed in a path between the raw material tank 150 and the electromagnetic valve 154.

  The polymer material is not particularly limited, and any polymer that is soluble in a solvent can be used. Although it does not specifically limit as a density | concentration of a polymeric material solution, For example, 1 to 20 weight% can be illustrated. The viscosity of the polymer material solution is not particularly limited.

  In the first step, two sample attachment plates (the first sample attachment plate 120 and the second sample attachment plate 130) in a state where the sample attachment surfaces (the first sample attachment surface 122 and the second sample attachment surface 132) are brought close to each other. After the polymer material solution is supplied between the two sample attachment plates (the first sample attachment plate 120 and the second sample attachment plate 130), the two sample attachment plates are vibrated in the direction in which the interval changes. More preferably, the polymer material solution is adapted by vibrating at least one of the sample attachment plates (the first sample attachment plate 120 and the second sample attachment plate 130) along the circumferential direction around the axis.

  The second sample attachment plate 130 (and the inner cylinder member 136) is moved in the left-right direction against the compressive stress or extension stress of the coil spring 142 by the motor described above.

  The first step is performed in a state where the sample attachment surfaces 122 and 132 are heated to a predetermined temperature (for example, 30 ° C. to 100 ° C.) by heating the heaters 124 and 134. In addition, when using a molten polymer material as a viscoelastic body, a 1st process is performed in the state heated, for example to 100 to 300 degreeC.

(2) Second Step The second step produces the nanofiber 10 by stretching the polymer material by rapidly separating the two sample attachment plates (the first sample attachment plate 120 and the second sample attachment plate 130). This is a process (see FIGS. 5D to 6A).

  The second step is performed by compression of a retractable coil spring 142 fixed to the second sample attaching plate 130 (and the inner cylinder member 136). The second sample adhering plate 130 (and the inner cylinder member 136) can regulate the movement in the left-right direction in FIG. 2A by a clasp mechanism (not shown). By removing the clasp mechanism, the second sample attachment plate 130 moves vigorously in the right direction in FIG.

  The speed at which the two sample attachment plates (the first sample attachment plate 120 and the second sample attachment plate 130) are separated and the degree of acceleration / deceleration depend on the type and viscosity of the polymer material solution to be used, but the produced polymer nano What is necessary is just to determine an optimal value, measuring the diameter of a fiber.

(3) Third Step The third step is a step of collecting the nanofibers 10 that are stretched between the two sample attachment plates (the first sample attachment plate 120 and the second sample attachment plate 130) ( (Refer FIG.6 (b)-FIG.6 (d).).

  In the third step, the nanofiber recovery plate 168 for recovering the nanofiber 10 is placed in a direction perpendicular to the direction in which the two sample attachment plates (the first sample attachment plate 120 and the second sample attachment plate 130) are separated from each other. By moving, the polymer nanofiber aggregate 12 is collected as the polymer nanofiber.

  By performing the above steps, the nanofibers 10 can be manufactured, and the manufactured nanofibers 10 can be collected as a nanofiber aggregate 12.

3. Effects of Nanofiber Manufacturing Method, etc. According to the nanofiber manufacturing method according to Embodiment 1 described above, it is extremely simple that only the two sample attachment plates with the polymer material solution sandwiched therebetween are suddenly separated. With this method, ultrafine nanofibers having an average diameter of 1000 nm or less can be produced. As a result, the nanofiber manufacturing method according to Embodiment 1 is a nanofiber manufacturing method capable of manufacturing nanofibers in a very simple process and without requiring a large-scale mechanism.

  In addition, according to the method for producing nanofibers according to Embodiment 1, the nanofibers are produced by stretching the polymer material in the direction in which the sample attachment plate is pulled away. As a result, the nanofibers having good orientation and crystallinity and high strength. Can be manufactured.

  Further, according to the method for producing nanofibers according to Embodiment 1, a solvent (for example, cyclohexane) that cannot be used alone in the electrospinning method can be used. Therefore, in the method for producing nanofibers using the electrospinning method, It is also possible to produce polymer nanofibers of a type that are not easy to produce (for example, polymer nanofibers made of polypropylene).

  Moreover, according to the manufacturing method of the nanofiber which concerns on Embodiment 1, since it is supposed to repeat the elementary process which contains a 1st process-a 3rd process in this order in multiple times, it manufactures a very fine nanofiber with high productivity. can do.

  In addition, according to the nanofiber manufacturing method according to the first embodiment, the first step is performed by bringing the sample attachment surfaces 122 and 132 close to each other through the viscoelastic body supply hole 126 formed in the first sample attachment surface 122 in advance. Since the polymer material solution is supplied between the two sample attachment plates (the first sample attachment plate 120 and the second sample attachment plate 130) in the state of being made, the two sample attachment plates (first A state in which the polymer material solution is sandwiched between the sample attaching plate 120 and the second sample attaching plate 130) can be formed relatively easily.

  Further, according to the nanofiber manufacturing method according to the first embodiment, the first step is performed in a state where the first sample attachment surface 122 and the second sample attachment surface 132 are heated to a predetermined temperature. When the temperature of the molecular material can be increased and the two sample attachment plates (the first sample attachment plate 120 and the second sample attachment plate 130) are rapidly separated to extend the polymer material, The solvent of the solution is removed, and it becomes possible to produce high-quality nanofibers with extremely low solvent content. In addition, since the polymer material can be stretched at a temperature higher than the glass transition temperature, high-quality nanofibers can be produced.

  In addition, according to the nanofiber manufacturing method according to the first embodiment, the second step is performed by the extension of the coil spring provided on the second sample attachment plate 130, so that two sample attachment plates (first sample) The operation of rapidly separating the attachment plate 120 and the second sample attachment plate 130) can be performed at high speed.

  Further, according to the nanofiber manufacturing method according to the first embodiment, in the third step, the nanofiber recovery plate 168 for recovering the nanofibers is divided into two sample attachment plates (the first sample attachment plate 120 and the first sample attachment plate 120). By moving the two sample attachment plates 130) in a direction perpendicular to the direction in which they are separated, the nanofiber assembly 12 is collected as nanofibers. Therefore, the two sample attachment plates (the first sample attachment plate 120 and the first sample attachment plate 130) are collected. The nanofibers 10 in a state of being stretched between the two sample attachment plates 130) can be collected as a nanofiber assembly 12.

[Modifications 1 to 4]
The manufacturing method of the nanofiber which concerns on Embodiment 1 can be implemented also with the following modifications 1-4. FIG. 7 is a view for explaining the viscoelastic body supply apparatus according to the first modification. FIG. 8 is a diagram for explaining the viscoelastic body supply apparatus according to the second modification. FIG. 9 is a view for explaining the second sample attachment plate 136 in the third modification. FIG. 10 is a diagram for explaining the operation of the second sample attachment plate 130 in the fourth modification.

  In the nanofiber manufacturing method according to Modification 1, as shown in FIG. 7, the first step is performed in a state where the sample attachment surfaces (the first sample attachment surface 122 and the second sample attachment surface 132) are brought close to each other. Using the nozzle 156 connected to the other end of the connection line 152 between the two sample attachment plates (the first sample attachment plate 120 and the second sample attachment plate 130), the two sample attachment plates (first sample attachment) The polymer material solution is immersed from the outer periphery of the plate 120 and the second sample attachment plate 130). Even with this method, it is relatively easy to form a state in which the polymer material solution is sandwiched between the two sample attachment plates (the first sample attachment plate 120 and the second sample attachment plate 130). Is possible.

  In the nanofiber manufacturing method according to Modification 2, as shown in FIG. 8, in the first step, each sample attachment surface (the first sample attachment surface 122 and the second sample attachment surface 132) is separated by a predetermined amount. After discharging the polymer material solution from the nozzle 158 connected to the other end of the connection line 152 toward the sample attachment surface 132 of the second sample attachment plate 130 in the state, two sample attachment surfaces (first sample attachment surface) 122 and the second sample attachment surface 132) are brought close to each other. Even with this method, it is relatively easy to form a state in which the polymer material solution is sandwiched between the two sample attachment plates (the first sample attachment plate 120 and the second sample attachment plate 130). Is possible.

  In the method for producing polymer nanofibers according to Modification 3, as shown in FIG. 9, as the second sample attachment plate, the height of the sample attachment surface within the range of 0.01 mm to 0.5 mm is regulated. Nanofibers are manufactured using a second sample attachment plate 138 in which a plurality of protrusions 139 are formed on the sample attachment surface. By adopting such a method, it becomes possible to accurately control the layer thickness of the polymer material solution sandwiched between two sample attachment plates in the state where the sample attachment surfaces facing each other are close to each other.

  In the method for producing polymer nanofibers according to the modified example 4, as shown in FIG. 10, the two sample attachment surfaces are separated by a distance d (d = 0.01 mm to 0.00 mm) by moving with a motor according to a predetermined procedure. 5 mm). By adopting such a method, it becomes possible to accurately control the layer thickness of the polymer material solution sandwiched between two sample attachment plates in the state where the sample attachment surfaces facing each other are close to each other.

[Embodiment 2]
FIG. 11 is a diagram for explaining the method for producing nanofibers according to the second embodiment. 11 (a) to 11 (c) are process diagrams of the main part of the nanofiber manufacturing apparatus 102 as viewed from above, and FIG. 11 (d) is a nanofiber manufacturing apparatus 102 of FIG. 11 (c). It is the figure which looked at the principal part of from the front. FIG. 12 is a view for explaining the method for manufacturing “the yarn made of nanofibers” according to the second embodiment.

  The nanofiber manufacturing method according to the second embodiment basically includes the same steps as the nanofiber manufacturing method according to the first embodiment, but the content of the third step is that of the polymer nanofiber according to the first embodiment. This is different from the manufacturing method. That is, in the nanofiber manufacturing method according to the second embodiment, as shown in FIG. 11, each time the third step is performed, two sample attachment plates (a first sample attachment plate 120 and a second sample attachment plate 130). The collected nanofiber aggregate 12 is placed on an endless belt 172 that moves intermittently or continuously along the direction in which it is separated. By setting it as such a method, the nanofiber 10 in the state extended | stretched between two sample attachment plates (the 1st sample attachment plate 120 and the 2nd sample attachment plate 130) is made into the extending | stretching axis | shaft of the nanofiber 10. FIG. It can collect | recover as the aggregate | assembly 14 of elongate nanofiber along a perpendicular direction. In the nanofiber manufacturing method according to the second embodiment, the long nanofiber assembly 16 in a bundled state can be wound around the winding drum 178 by the function of the regulating member 174. Reference numeral 176 denotes a conveyance roller. In addition, a plurality of regulating members may be provided, and a plurality of elongated nanofiber assemblies 16 in a bundled state may be wound around the winding drum 178.

  Therefore, by passing the long nanofiber assembly 16 produced by the nanofiber production method according to the second embodiment into the main twisting device 180 in the twisting device 200 as shown in FIG. It becomes possible to manufacture “the yarn 18 made of nanofibers” from the assembly 16 (the manufacturing method of “the yarn made of nanofibers” according to the second embodiment). By adopting such a method, it is possible to produce a “strength made of nanofibers” having a high degree of orientation and crystallinity in a very simple process and without requiring a large-scale mechanism. .

[Embodiment 3]
FIG. 13 is a view for explaining the nanofiber manufacturing method according to the third embodiment.
The method for producing nanofibers according to Embodiment 3 basically includes the same steps as the method for producing nanofibers according to Embodiment 1, but the content of the third step is that of the polymer nanofiber according to Embodiment 1. This is different from the manufacturing method. That is, in the nanofiber manufacturing method according to the third embodiment, as shown in FIG. 13, each time the third step is performed, two sample attachment plates (a first sample attachment plate 120 and a second sample attachment plate 130). The collected nanofiber aggregates are placed on a rotating drum that rotates intermittently or continuously around an axis that is parallel to the direction in which they are separated. By setting it as such a method, the nanofiber 10 in the state extended | stretched between two sample attachment plates (the 1st sample attachment plate 120 and the 2nd sample attachment plate 130) is made into the extending | stretching axis | shaft of the nanofiber 10. FIG. It can be recovered as a long nanofiber assembly 20 along the vertical direction. In the nanofiber manufacturing method according to the third embodiment, the long nanofiber aggregate 20 is wound around the winding drum 194 by the functions of the rotating drum 190, the transport roller 192, and the winding drum 194. Can do.

[Embodiment 4]
14-15 is a figure shown in order to demonstrate the manufacturing method of the "thread which consists of nanofibers" concerning Embodiment 4. FIG. 14A is a schematic view of the main part of the nanofiber manufacturing apparatus 106 according to the fourth embodiment as viewed from above, and FIG. 14B is a front view of the main part of the nanofiber manufacturing apparatus 106 according to the fourth embodiment. It is the schematic diagram seen from. FIG. 15A to FIG. 15D are process diagrams, and FIG. 15E is a diagram illustrating an assembly 20 of sheet-like nanofibers to be manufactured. FIGS. 15A and 15C are views of the main part of the nanofiber manufacturing apparatus 106 as viewed from above, and FIGS. 15B and 15D are nanofiber manufacturing apparatuses. It is the figure which looked at the principal part of 106 from the front.

  The nanofiber manufacturing method according to the fourth embodiment basically includes the same steps as the nanofiber manufacturing method according to the first embodiment. However, as shown in FIGS. It differs from the manufacturing method of the nanofiber which concerns on Embodiment 1 by the point which manufactures nanofiber using 2 sets. That is, in the nanofiber manufacturing method according to the fourth embodiment, two sample attachment plates (“first sample attachment plate 120a and second sample attachment plate 130a”, first sample attachment plate 120b and second sample attachment plate 130b). )) Are prepared (see FIG. 14), and these two sets of “two sample attachment plates” are arranged so that the separating directions are orthogonal to each other, and the first step to the third step are performed. Is performed sequentially (alternately) on two sets of “two sample attachment plates” to collect a collection of sheet-like nanofibers in which nanofiber layers having different stretching axes are sequentially laminated. (See FIG. 15). By setting it as such a method, the nanofiber in the state extended | stretched between two sample adhesion plates can be collect | recovered as an aggregate | assembly of a sheet-like nanofiber.

[Embodiment 5]
FIG. 16 is a view for explaining the method of manufacturing “the yarn made of nanofibers” according to the fifth embodiment. FIG. 16 (a) is a view for explaining the nanofibers before the third step, and FIG. 16 (b) illustrates the “thread made of nanofibers” immediately before the nanofibers are collected in the third step. It is a figure shown in order to do.

  The nanofiber manufacturing method according to Embodiment 5 basically includes the same steps as the nanofiber manufacturing method according to Embodiment 1, but the contents of the third step are the nanofiber manufacturing method according to Embodiment 1. It is different from the case of. That is, in the method for manufacturing “a nanofiber yarn” according to the third embodiment, as shown in FIG. 16, in the third step, the second sample attachment plate 130 is rotated around an axis perpendicular to the second sample attachment surface 132. The “thread 22 made of nanofibers” (refer to FIG. 16A and FIG. 16B), which is in a twisted state by rotating in the direction, is collected. By adopting such a method, it is possible to produce a high-strength “yarn made of nanofibers” with excellent orientation and crystallinity without requiring a large-scale mechanism in a very simple process. it can.

[Example 1]
In Example 1, nanofibers were manufactured manually by the method shown in FIG. That is, an appropriate amount of viscoelastic body was dropped between the thumb and index finger, and then the gap between the thumb and index finger was widened to produce nanofibers. As the viscoelastic body, a polymer material solution containing 15% by weight of polyvinyl acetate (weight average molecular weight: 500,000) in ethanol was used.

  Thereafter, an optical micrograph and a scanning electron micrograph of the manufactured nanofiber were taken. FIG. 17 is an optical micrograph of nanofibers produced in Example 1. FIG. 18 is a scanning electron micrograph of the nanofibers produced in Example 1. As shown in FIGS. 17 and 18, it was found that ultrafine nanofibers made of polyvinyl acetate can be produced by the method shown in FIG.

  Then, the X-ray diffraction measurement of the manufactured nanofiber was performed. FIG. 19 is an X-ray diffraction chart of the nanofiber produced in Example 1. In FIG. 19, the solid line indicates the X-ray diffraction data of the nanofiber manufactured in Example 1, and the broken line indicates the X-ray diffraction data of the nanofiber separately manufactured by the electrospinning method. As shown in FIG. 19, it was found that the nanofiber produced in Example 1 had slightly higher crystallinity than the nanofiber produced by the electrospinning method. That is, when the nanofiber manufactured in Example 1 and the nanofiber manufactured by the electrospinning method are compared, the main peak (2θ = 12 °) has almost the same strength, but the sub-peak (2θ = 22). °) the nanofibers produced in Example 1 have greater strength.

[Example 2]
Also in Example 2, nanofibers were manufactured manually by the method shown in FIG.
That is, an appropriate amount of viscoelastic body was dropped between the thumb and index finger, and then the gap between the thumb and index finger was widened to produce nanofibers. As the viscoelastic body, a polymer material solution containing 5% by weight of syndiotactic polypropylene (weight average molecular weight: 127,000) in cyclohexane was used.

  Thereafter, a scanning electron micrograph of the manufactured nanofiber was taken. 20 is a scanning electron micrograph of nanofibers produced in Example 2. FIG. As shown in FIG. 20, it was found that ultrafine nanofibers made of syndiotactic polypropylene can be produced by the method shown in FIG. Since syndiotactic polypropylene cannot be used alone as a solvent for dissolving it, it is not easy to produce polymer nanofibers composed of syndiotactic polypropylene by electrospinning. On the other hand, according to Example 2, it is possible to easily produce polymer nanofibers made of such syndiotactic polypropylene.

  Thereafter, in Example 2, the produced polymer nanofiber was twisted to produce “yarn made of nanofiber”. FIG. 21 is a scanning electron micrograph of the “thread made of nanofibers” produced in Example 2. As shown in FIG. 21, in Example 2, it was found that “nanofiber yarn” can be manufactured.

[Example 3]
Also in Example 3, nanofibers were manufactured manually by the method shown in FIG. That is, an appropriate amount of viscoelastic body was dropped between the thumb and index finger, and then the gap between the thumb and index finger was widened to produce nanofibers. As the viscoelastic body, a molten polymer material obtained by melting isotactic polypropylene (melt flow rate: 1,200) was used.

  Thereafter, a scanning electron micrograph of the manufactured nanofiber was taken. FIG. 22 is a scanning electron micrograph of the nanofibers produced in Example 3. As shown in FIG. 22, it was found that ultrafine nanofibers made of isotactic polypropylene can be produced by the method shown in FIG.

  As mentioned above, although the manufacturing method of the nanofiber of this invention, the manufacturing apparatus of nanofiber, and the manufacturing method of "the thread | yarn consisting of nanofiber" were demonstrated based on said embodiment, this invention is not limited to this. However, the present invention can be carried out without departing from the scope of the invention. For example, the following modifications are possible.

(1) In Embodiment 1 described above, the second step is performed by extending the coil spring, but the present invention is not limited to this. For example, the second step may be performed by compression of a coil spring. Further, the second step may be performed not only by the coil spring but also by extension or compression of a pneumatic spring or a hydraulic spring. Moreover, you may perform a 2nd process with a motor.

(2) In Embodiment 1 described above, the nanofiber recovery plate is moved so as to draw an arc by rotating the arm, but the present invention is not limited to this. For example, the nanofiber recovery plate may be moved linearly.

(3) Although nanofibers are manufactured using the nanofiber manufacturing apparatus 100 in the first embodiment, the present invention is not limited to this. You may manufacture a nanofiber using the manufacturing apparatus of the nanofiber of another structure.

(4) In Examples 1 to 3, nanofibers were produced from polyvinyl acetate, syndiotactic polypropylene, and isotactic polypropylene, but the present invention is not limited to this. Various polymers can be used.

(5) In Examples 1 to 3, a viscoelastic body made of a polymer material (a polymer material solution in Examples 1 and 2 and a molten polymer material in Example 3) is used as the viscoelastic body. Although nanofibers were manufactured, the present invention is not limited to this. A viscoelastic body other than the polymer material, for example, a viscoelastic body made of a low molecular material, a molten metal material, or the like can also be used.

DESCRIPTION OF SYMBOLS 10 ... Nanofiber, 12 ... Aggregate of nanofiber, 14, 16, 20 ... Aggregate of long nanofiber, 18, 22 ... Thread made of nanofiber, 100, 102, 104, 106, 108 ... Nanofiber 110 ... base, 112 ... first base, 114 ... second base, 120 ... first sample attachment plate, 122 ... first sample attachment surface, 124 ... heater, 126 ... viscoelastic body supply hole , 130, 138 ... second sample attachment plate, 132 ... second sample attachment surface, 134 ... heater, 136 ... inner cylinder member, 139 ... projection for regulating the sample attachment surface interval, 140 ... outer cylinder member, 142 ... coil spring, 144 ... motor, 150 ... raw material tank, 152 ... connection line, 154 ... electromagnetic valve, 160 ... nanofiber recovery device, 162 ... motor, 164 ... arm, 166 ... support, 168 ... nanofiber recovery plate, 170 ... Roh fiber recovery tray, 172 ... endless belt, 174 ... regulating member, 176,192 ... transport rollers, 178,194 ... winding drum, 180 ... yarn device, 182, 184 ... roller, 190 ... rotary drum

Claims (22)

A first step of forming a state in which a viscoelastic body is sandwiched between two sample attachment plates in a state where the sample attachment surfaces facing each other are close to each other;
A second step of producing nanofibers by stretching the viscoelastic body by rapidly separating the two sample attachment plates;
And a third step of collecting the nanofibers in a state of being stretched between the two sample attachment plates in this order. In the manufacturing method of the nanofiber of Claim 1,
A method for producing a nanofiber assembly, wherein the elementary steps including the first step to the third step in this order are repeated a plurality of times. In the manufacturing method of the nanofiber of Claim 1 or 2,
The first step is performed between the two sample attachment plates in a state in which the sample attachment surface is brought into proximity through a viscoelastic body supply hole formed in advance on at least one of the two sample attachment plates. A method for producing nanofibers, comprising supplying the viscoelastic body. In the manufacturing method of the nanofiber of Claim 1 or 2,
The first step is performed by immersing the viscoelastic body from the outer periphery of two sample attachment plates between the two sample attachment plates in a state where the sample attachment surfaces are close to each other. A method for producing nanofibers. In the manufacturing method of the nanofiber of Claim 1 or 2,
In the first step, the viscoelastic body is discharged from a nozzle toward at least one of the two sample attachment plates in a state where the sample attachment surface is separated by a predetermined amount. A method for producing nanofibers, wherein the method is carried out by bringing the sample attachment surface close to each other. In the manufacturing method of the nanofiber in any one of Claims 1-5,
The method for producing nanofibers, wherein the first step is performed in a state where the sample attachment surface is heated to a predetermined temperature. In the manufacturing method of the nanofiber in any one of Claims 1-6,
The method for producing nanofibers, wherein the second step is performed by moving at least one of the two sample attachment plates by extension or compression of a spring. In the manufacturing method of the nanofiber in any one of Claims 1-6,
The method for producing nanofibers, wherein the second step is performed by moving at least one of the two sample attachment plates with a motor according to a predetermined procedure. In the manufacturing method of the nanofiber according to claim 8,
In the first step, at least one of the two sample attachment plates is moved by a motor according to a predetermined procedure, so that the two sample attachment surfaces are brought close to each other within a range of 0.01 mm to 0.5 mm. The manufacturing method of the nanofiber characterized by the above-mentioned. In the manufacturing method of the nanofiber in any one of Claims 1-8,
A plurality of protrusions for regulating the interval between the sample attachment surfaces having a height in the range of 0.01 mm to 0.5 mm are formed on at least one sample attachment surface of the sample attachment plates. A method for producing nanofibers. In the manufacturing method of the nanofiber according to claim 2,
Each time the third step is performed, a nanofiber recovery plate for recovering the nanofiber is moved in a direction perpendicular to the direction in which the two sample attachment plates are separated from each other. A method for producing nanofibers, comprising collecting an assembly of In the manufacturing method of the nanofiber according to claim 11,
The method for producing nanofibers, wherein the nanofiber recovery plate has a recovery surface formed on a rough surface. In the manufacturing method of the nanofiber of Claim 11 or 12,
In collecting the nanofibers, the nanofibers are separated from the nanofiber collection plate by suction force. In the manufacturing method of the nanofiber in any one of Claims 11-13,
Each time the third step is performed, the collected nanofiber aggregate is placed on an endless belt that moves intermittently or continuously along the direction in which the two sample attachment plates are separated. Thus, as the nanofiber, a long nanofiber aggregate is collected along the stretching axis of the nanofiber. In the manufacturing method of the nanofiber according to claim 11,
Each time the third step is performed, the collected nanofiber aggregate is placed on a rotating drum that rotates intermittently or continuously around an axis in the direction in which the two sample attachment plates are separated. Thus, as the nanofiber, a long nanofiber aggregate is collected along a direction perpendicular to the stretching axis of the nanofiber, and the nanofiber manufacturing method is characterized in that it collects. In the manufacturing method of the nanofiber according to claim 11,
At least two sets of the two sample attachment plates are prepared, and at least two sets of the “two sample attachment plates” are arranged so that the separating directions intersect each other.
A sheet-like state in which nanofiber layers having different stretching axes are sequentially laminated by sequentially performing the first process to the three processes on the at least two sets of “two sample attachment plates”. A method for producing nanofibers, comprising collecting an assembly of nanofibers. In the manufacturing method of the nanofiber in any one of Claims 1-16,
The method for producing nanofibers, wherein the viscoelastic body is a polymer material solution containing a polymer material or a molten polymer material obtained by melting a polymer material. In the manufacturing method of the nanofiber in any one of Claims 1-16,
The method for producing nanofibers, wherein the viscoelastic body is a low molecular material solution containing a low molecular material or a molten low molecular material obtained by melting a low molecular material. In the manufacturing method of the nanofiber in any one of Claims 1-16,
The method for producing nanofibers, wherein the viscoelastic body is a molten metal material obtained by melting a metal material. A nanofiber manufacturing apparatus for carrying out the nanofiber manufacturing method according to claim 1,
The base,
Two sample attachment plates installed on the base and having sample attachment surfaces facing each other;
A viscoelastic body supply device for supplying a viscoelastic body between the two sample attachment plates;
A sample attachment plate separating apparatus for producing nanofibers by stretching the viscoelastic body by rapidly separating the two sample attachment plates;
An apparatus for producing nanofibers, comprising: a nanofiber recovery device that recovers the nanofibers in a state of being stretched between the two sample attachment plates.   The nanofiber manufactured by the method for manufacturing a nanofiber according to any one of claims 1 to 19 is passed through a twisted yarn device to manufacture a "yarn made of nanofiber" from the nanofiber. A manufacturing method of “a thread made of nanofiber”. A method for producing a "yarn comprising nanofibers", which produces a "yarn comprising nanofibers" using the nanofiber produced by the method for producing nanofibers according to any one of claims 1 to 19,
In the third step, at least one of the two sample attachment plates is rotated around an axis perpendicular to the sample attachment surface, and the “yarn made of nanofibers” that has been twisted is collected. A process for producing “threads composed of nanofibers”.