JP4954946B2 - Nanofiber manufacturing equipment - Google Patents

Description

  The present invention relates to a nanofiber manufacturing apparatus and manufacturing method, and more particularly to a technique for manufacturing nanofibers using electrostatic explosion.

  In recent years, the electrospinning method (charge-induced spinning method) has attracted attention because nanofibers, which are fibrous materials having submicron diameters, can be easily produced. In the electrospinning method, a raw material liquid in which a polymer material is dispersed or dissolved in a solvent is released into the air, and at the time of release, the raw material liquid is charged at a high voltage, and the raw material liquid is electrostatically exploded in the air to produce nano-scales. This is a method for obtaining a fiber (see, for example, Patent Document 1).

  More specifically, the raw material liquid charged by a high voltage and released into the air evaporates the solvent while flying in the air, and the volume decreases. On the other hand, since the charge imparted to the raw material liquid is maintained regardless of the evaporation of the solvent, the charge density of the raw material liquid increases with the evaporation of the solvent. Then, when the coulomb force in the repulsion direction inside the raw material liquid becomes larger than the surface tension of the raw material liquid, a phenomenon (electrostatic explosion) in which the raw material liquid is explosively stretched linearly occurs. This electrostatic explosion is continuously generated in the air, and the raw material liquid is subdivided into a geometrical linear shape, thereby forming fine fibers having a submicron-scale diameter.

  Patent Document 2 proposes a manufacturing apparatus that discharges a raw material liquid from a rotary container and manufactures nanofibers by an electrospinning method. In this apparatus, as shown in FIG. 10, a spray head 52 having at least one extrusion element 51 on the peripheral wall is disposed inside a cylindrical collection body 53, and nanofibers are manufactured by an electrospinning method. A voltage is applied to the spray head 52 and the collector 53 by a high voltage power source 54 so that an electric field is generated therebetween. By rotating the spray head 52 in this state, the raw material liquid 56 supplied into the spray head 52 through the tube 55 is extracted from the tip of the extrusion element 51 by an electric field, and nanofibers are generated. The generated nanofibers are deposited and collected on the inner peripheral surface of the collection body 53.

  According to the apparatus of Patent Document 2, the nanofibers collected by the collection body have orientation, but the nanofibers are deposited on the inner peripheral surface of the collection body, so that it is very difficult to collect the nanofibers. It is. This is an obstacle to mass production of nanofibers.

  In order to solve such a problem, as shown in FIG. 11, the present inventors rotate a cylindrical container 61 having a large number of pores 62 on the peripheral wall around an axis, The nanofiber raw material solution 63 is released from the pores 62 to the outside, and a method for producing the nanofibers by deflecting the raw material solution released from the pores 62 by an air flow has already been invented. In this method, the raw material liquid 63 discharged radially from the pores 62 in the radial direction of the container 61 is changed in the axial direction of the container 61 by the air flow. A long strip-shaped collecting body (not shown) is arranged at the tip of the airflow direction, and nanofibers are deposited on the surface and collected. Then, by sending the collection body in the longitudinal direction, it becomes possible to collect the nanofibers while continuously producing them. Therefore, mass production of nanofibers becomes possible. In FIG. 11, the sign of + (plus) is indicated by a circled symbol that the raw material liquid 63 has a positive charge.

Japanese Patent Laying-Open No. 2005-330624 JP 2007-532790 A

  In the above-mentioned inventions of the present inventors, a large number of pores (discharge holes) are formed in the peripheral wall of the container in order to increase the production amount of nanofibers. Further, from the viewpoint of uniformly depositing nanofibers uniformly on the collection body and from the viewpoint of facilitating the manufacture of the container, such a large number of discharge holes are formed so as to be regularly arranged on the peripheral wall of the container. Is preferred.

  For this reason, as shown in FIG. 10, the discharge holes are formed so as to be arranged in rows parallel to each other in the axial direction of the container, that is, the direction of the airflow. As a result, the raw material liquid discharged from each discharge hole or the nanofiber (hereinafter referred to as the raw material liquid) generated therefrom may overlap each other as shown in the figure. In such a case, the amount of overlapping raw material liquid increases toward the downstream side, and the charged raw material liquid is filled around the discharge hole located at the most downstream side. As a result, charging of the raw material liquid discharged from the downstream discharge hole may be inhibited, or release of the raw material liquid from the discharge hole may be inhibited.

When charging of the raw material liquid is inhibited, the electric charge given to the raw material liquid is reduced, and electrostatic explosion is difficult to occur, so that the raw material liquid remains in the form of droplets and reaches the collector. In this case, a mass of a dumpling polymer substance is mixed with nanofibers made of fine fibers, which causes the quality of the nanofibers to deteriorate.
In addition, when the release of the raw material liquid from the discharge hole is hindered, it becomes difficult to uniformly deposit the nanofibers on the collection body, and in this case also the quality of the nanofibers is lowered.

  The present invention has been made in view of the above problems, and is a nanofiber manufacturing apparatus capable of manufacturing high-quality nanofibers that are composed of only fine-diameter fibers and are uniformly integrated, and manufacturing. It aims to provide a method.

To achieve the above object, the nano-fiber manufacturing apparatus of the present invention, a plurality of discharge holes for discharging the raw material liquid containing a polymeric material which is held inside to the outside, is formed in the outer wall, at least the A container in which the opening of the discharge hole is formed of a conductor;
An electrode disposed opposite to the discharge hole of the container;
A power source for applying a potential difference between the electrode and the container so as to charge the raw material liquid discharged from the discharge hole of the container;
A force application mechanism that applies force to the raw material liquid so as to discharge the raw material liquid from the discharge hole toward the electrode;
A transfer means for transferring the raw material liquid discharged from the discharge hole or the fibrous material generated by electrostatic explosion from the raw material liquid in a direction substantially perpendicular to the discharge direction of the raw material liquid by being deflected by an air current;
Collecting means for collecting the fibrous material transferred by the transfer means,
Said transfer means, viewed including the air flow adjusting means each of said raw material liquid or the fibrous material which is discharged from the discharge hole to adjust the air flow to disperse the path proceeding is deflected by the air flow in the discharge direction,
The container has a cylindrical shape with at least one end closed,
The discharge hole is formed in the peripheral wall of the container,
The force application mechanism includes a rotation drive mechanism that rotates the container,
The electrode includes a substantially cylindrical conductor disposed coaxially around the container,
The air flow adjusting means includes a gap for allowing the air flow to flow into a space between the peripheral wall of the container in which the discharge hole is formed and the electrode, and the discharge of the air flow. A substantially circular plate member disposed on the upstream side of the hole is included .
Here, it is preferable that the plurality of discharge holes are distributed in the axial direction of the container, and at least a part of the plurality of discharge holes is arranged in a line in the axial direction of the container. Is also preferable.

Or, nanofiber manufacturing apparatus of the present invention, the transfer means comprises a gas supply means for supplying a gas at a predetermined pressure,
The air flow adjusting means is
The gas supplied by the gas supply means includes ejection means for unloading position or al-injection in the vicinity of the inner peripheral surface of the electrode in the space between the wall and the electrode of the container the discharge hole is formed .
Here, the ejection means has a hollow portion that temporarily holds the gas supplied by the gas supply means, and at least one ejection hole or ejection groove that ejects the gas held in the hollow portion is one end. It is preferable that the annular member provided in the part is included .

Alternatively, in the nanofiber manufacturing apparatus of the present invention, the air flow adjusting means is
A gap for allowing the airflow to flow into the space between the peripheral wall of the container in which the discharge hole is formed and the electrode is disposed between the outer peripheral surface of the container and is more than the discharge hole of the airflow. A substantially circular plate member disposed on the upstream side;
Disposed in the gap, including a cylindrical member whose diameter increases toward the downstream side from the upstream side of the air flow.

  According to the present invention, the air flow is distributed in the discharge direction of the raw material liquid along the path in which the raw material liquid or the fibrous material discharged from the discharge holes arranged in a row is deflected by the air flow by the air flow adjusting means. Adjusted. As a result, overlapping of the raw material liquid discharged from each discharge hole and transported by the airflow is prevented, so that charging of the raw material liquid discharged from the downstream discharge hole is hindered or from the raw material liquid discharge hole. Can be prevented from being inhibited. As a result, even if the amount of the raw material liquid discharged from the discharge hole is increased, it is possible to prevent the quality of the manufactured nanofiber from being deteriorated. Therefore, it is possible to mass-produce high-quality nanofibers with a uniform accumulation amount, which are composed only of fine-diameter fibers that are not mixed with a lump of polymer substance.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
<Embodiment 1>
FIG. 1 is a side view, partly in section, showing a schematic configuration of a nanofiber manufacturing apparatus according to Embodiment 1 of the present invention. FIG. 2 is an enlarged view of a portion of the apparatus of FIG. FIG. 3 is a perspective view of a portion in the vicinity of the container 2 with the annular electrode removed from the apparatus of FIG.

  The manufacturing apparatus 1 includes a grounded container 2 having a substantially cylindrical shape made of a conductor. The container 2 temporarily holds a raw material liquid F obtained by dispersing or dissolving a polymer material that is a raw material of nanofibers, and is formed from a large number of pores for discharging the raw material liquid F to the outside on the peripheral wall. It has a discharge hole 2a (see FIG. 2). Further, around the container 2, an annular electrode (induction electrode) 3 is coaxially disposed so that the inner peripheral surface faces the outer peripheral surface of the container 2 at a certain distance. The annular electrode 3 is connected to the other terminal of the high-voltage power supply 7 whose one terminal is grounded. As a result, charges having a polarity opposite to that of the annular electrode 3 are induced on the peripheral surface of the container 2.

  Further, the discharge holes 2 a are formed at equal intervals on the peripheral wall of the container 2 at a portion facing the annular electrode 3 so as to form a row parallel to the axial direction of the container 2. The rows are arranged at equal pitches in the circumferential direction of the container 2.

  Further, the container 2 is rotatably supported by the support portion 11 via the bearing 12. A rotating shaft 2c is erected on the wall surface closing one end of the container 2 so as to penetrate the hollow portion 2b and extend from the cylindrical passage 2d to the outside. The rotating shaft 2 c is connected to the motor 13, and the container 2 is rotationally driven by the motor 13.

  Inside the container 2, the raw material liquid F is supplied at a predetermined pressure from a raw material liquid tank (not shown) through a raw material liquid supply pipe 15 provided through the inside of the support portion 11. In addition, a pipe 31 for inserting a conducting wire or the like for supplying electric power to the motor 13 is provided in the support portion 11 in parallel with the raw material liquid supply pipe 15.

  The raw material liquid F supplied to the inside of the container 2 is charged by the electric charge induced in the container 2 and having a polarity opposite to that of the annular electrode 3, and the discharge hole of the container 2 is generated by the electric field between the annular electrode 3 and the container 2. It is emitted from 2a toward the annular electrode 3. Further, the container 2 is rotationally driven by the motor 13 at a predetermined number of revolutions to assist the discharge of the raw material liquid F from the discharge hole 2a.

  The raw material liquid F discharged from the discharge hole 2a of the container 2 evaporates in the air and increases the coulomb force in the internal repulsion direction while flying in the air. It is subdivided into. Thus, the fibrous substance F1 is formed from the raw material liquid F by the Coulomb force.

  Here, in FIG. 1, the raw material liquid F and the fibrous substance F1 are distinguished for convenience. However, in actual production of nanofibers, the distinction between the raw material liquid F and the fibrous substance F1 is ambiguous, and it is difficult to draw a clear line of the existence area. Therefore, in the following description, the raw material liquid F and the fibrous substance F1 are described only when it is particularly necessary to distinguish, and in other cases, the raw material liquid F and the fibrous substance F1 are collectively referred to as the raw material liquid F and the like. It describes.

  A blower 4 is disposed on one end side of the container 2 in the axial direction. The blower 4 generates an air current for deflecting and transferring the direction in which the raw material liquid F travels in a direction (axial direction of the container 2) substantially perpendicular to the discharge direction (diameter direction of the container 2). On the other end side of the container 2 in the axial direction, a collector 5 serving as a collecting means for collecting the fibrous substance (nanofiber) F1 generated from the raw material liquid F by electrostatic explosion and transferred by the air flow is arranged. It is installed. A cylindrical guide body 20 is disposed between the blower 4 and the container 2 and the annular electrode 3 so as to define the flow path of the airflow. The airflow is not limited to that generated only by the blower 4, and the airflow is generated in cooperation with a suction mechanism 23 of the collector 5 and gas ejection from the gas outlet 9 a described later. Can be.

  An airflow adjusting member 41 is disposed at a boundary portion between the guide body 20 and the annular electrode 3. The airflow adjusting member 41 is a substantially circular plate-like member having a container loosely fitting hole 41a in which the container 2 is loosely fitted in the axial direction at the center. The air flow adjusting member 41 is arranged on the upstream side of the air flow from the portion where the discharge hole 2a of the container 2 is formed. The outer peripheral edge of the air flow adjusting member 41 and the inner peripheral surface of the annular electrode 3 are Opposing each other with a gap of a predetermined size. As shown in FIG. 2, the airflow generated by the blower 4 or the like is accelerated once when passing through the gap, and then is broken by a broken line from a position near the inner peripheral surface of the annular electrode 3 toward the outer peripheral surface of the container 2. It flows into the space between the container 2 and the annular electrode 3 while spreading as indicated by arrows H1 to H6.

  As a result, the raw material liquid F or the like discharged from the discharge hole 2a on the most upstream side of the airflow advances straight without receiving the deflection force of the airflow until it reaches the vicinity of the annular electrode 3, and near the annular electrode 3. Only when it arrives, the deflection force is received and the traveling direction is deflected in the axial direction of the container 2. On the other hand, the raw material liquid F and the like discharged from the discharge hole 2a on the most downstream side of the airflow is subjected to the deflection force immediately after the discharge by the airflow as indicated by arrows H3 and H6. The traveling direction is deflected in the axial direction of the container 2. In this way, each of the discharge holes 2a is arranged such that the direction in which the raw material liquid F discharged from the discharge hole 2a on the downstream side of the airflow advances in the position closer to the peripheral surface of the container 2 is deflected in the axial direction of the container 2. The traveling path of the raw material liquid F and the like released from is dispersed.

Accordingly, since the raw material liquid F and the like discharged from the upstream discharge hole 2a and the raw material liquid F and the like discharged from the downstream discharge hole 2a are prevented from overlapping, the most downstream discharge hole 2a. It is prevented that charging of the raw material liquid F released from the liquid is inhibited or that the discharging of the raw material liquid F from the most downstream release hole 2a is inhibited.
As a result, it is possible to prevent the mass of the polymer material from being mixed into the fibrous substance (nanofibers) collected by the collector 5 and the amount of accumulation of the fibrous substance from becoming uneven.

  Here, the container 2 may have an outer diameter of 10 mm to 300 mm. This is because if the diameter of the container 2 exceeds 300 mm, it is difficult to appropriately concentrate the raw material liquid F and the like by the air flow. Moreover, if the diameter of the container 2 exceeds 300 mm, in order to rotate the container 2 stably, it is necessary to considerably increase the rigidity of the support structure that supports the container 2, and the apparatus becomes large. On the other hand, if the diameter of the container is smaller than 10 mm, it is necessary to increase the rotational speed in order to obtain sufficient centrifugal force to release the raw material liquid, and in this case, the load and vibration of the motor increase. This is because it is necessary to take measures against vibration. Considering the above points, the outer diameter of the container 2 is more preferably 20 to 100 mm.

  The diameter of the discharge hole 2a is preferably 0.01 to 2 mm. The shape of the discharge hole 2a is preferably circular, but may be a polygonal shape or a star shape. Moreover, the rotation speed of the container 2 is adjusted in the range of several rpm or more and 10,000 rpm or less, for example, according to the viscosity of the raw material liquid F, the composition of the raw material liquid F (the type of polymer substance), and the diameter of the discharge hole 2a. be able to.

The annular electrode (induction electrode) 3 is a cylindrical member having a larger diameter than that of the container 2, and the inner diameter of the annular electrode 3 is preferably set to 200 to 800 mm, for example.
Further, it is preferable to apply a voltage of 1 to 200 kV from the power source 7 to the annular electrode 3. More preferably, a high voltage of 10 kV or higher is applied. In particular, the electric field strength between the container 2 and the annular electrode 3 is important, and it is preferable to arrange the applied voltage and the annular electrode 3 so that the electric field strength is 1 KV / cm or more. Thereby, an equal and strong electric field can be generated between the container 2 and the annular electrode 3.

  The annular electrode 3 (induction electrode) is not necessarily an annular electrode, and may be, for example, a polygonal annular electrode having a polygonal shape when viewed from the axial direction. Further, such an induction electrode may be disposed so as to surround the container 2 at a predetermined distance from the peripheral surface of the container 2. For example, an annular metal wire is disposed so as to surround the container 2. An induction electrode may be configured. When the induction electrode is an annular metal wire, for example, the end of the guide body 20 is extended so that the container 2 is surrounded by the guide body 20, and an annular metal wire is formed on the inner peripheral surface of the extended portion of the guide body 20. The air flow adjusting member 41 may be provided inside the guide body 20 so as to provide a gap between the wire and the inner peripheral surface of the guide body 20.

  Further, a blower is provided between the blower 4 and the container 2 so that the evaporation of the dispersion medium or the solvent from the raw material liquid F or the like can be promoted and the fibrous substance F1 can be quickly generated from the raw material liquid F. It is preferable to provide a heater 10 for heating the air blown by 4. By doing so, evaporation of the charged raw material liquid F is promoted, electrostatic explosion occurs early, and the fiber diameter of the fibrous substance F1 generated is further reduced, and the fine fibrous substance F1 is stably stabilized. Can be generated.

  Further, it is preferable to provide a cylinder 8 for defining a flow path for the raw material liquid F or the like by blowing air between the container 2 and the annular electrode 3 and the collector 5. The cylindrical body 8 has a large-diameter portion 8a that opens toward the container 2 and has an inner diameter substantially equal to the outer diameter of the annular electrode 3, a small-diameter portion 8b that opens facing the collector 5, and a large-diameter portion 8a and a small-diameter portion 8b. So that the diameter gradually decreases from the large diameter portion 8a side toward the small diameter portion 8b side. As described above, the cylindrical body 8 having a smaller opening on the downstream side than the opening on the upstream side is disposed between the container 2 and the collector 5 to define the flow path of the raw material liquid F, etc. It becomes possible to collect in the collection body 21 uniformly evenly with high density.

  Further, gas outlets 9a for injecting gas toward the inside of the cylindrical body 8 are formed in the vicinity of the boundary between the large diameter portion 8a and the intermediate portion 8c, and the small diameter portion 8b, that is, the upstream side and the downstream side of the intermediate portion 8c. It may be provided at a predetermined pitch in the circumferential direction of the cylinder 8. The gas outlet 9 a is supplied from the gas supply device 9 and jets the gas whose pressure is adjusted by the pressure regulating valve 9 b toward the inside of the cylinder 8 and the downstream side of the airflow generated by the blower 4. It is arranged. Thereby, the raw material liquid F and the like can be transferred to the collector 5 so that the raw material liquid F and the like do not adhere to the inner wall surface of the cylinder 8. Moreover, the airflow generated by the blower 4 or the like is accelerated.

  Next, the collector 5 will be described. The collector 5 includes a long strip-shaped collection body 21 that is arranged perpendicularly or substantially perpendicular to the transfer direction of the raw material liquid F by the blower of the blower 4, a feed mechanism 22 that sends the collection body 21 in its longitudinal direction, and a collection body 21 includes a suction mechanism 23 that sucks gas from the back side of the surface facing the container 2 to generate an air flow.

The collecting member 21 is a member for depositing and collecting the fibrous substance F1 formed from the raw material liquid F on the surface thereof. The collecting member 21 is made of a thin and flexible material so that an air flow for transporting the raw material liquid F or the like can pass through and the deposited fibrous substance F1 (nanofiber) can be easily separated. Preferably it is configured. As an example of a preferable material, a net-like sheet formed from aramid fibers can be given. If this is coated with Teflon (registered trademark), the separability of the fibrous substance F1 (nanofiber) is further improved, which is more preferable.
In general, the collecting member 21 is made of an insulating material, but is not limited thereto. A conductive material such as carbon nanofiber is mixed in a long sheet-like member. The collecting member 21 may be made conductive.

  The feeding mechanism 22 includes an unwinding roll 22 a that unwinds the collection body 21 and a winding roll 22 b that winds the collection body 21. The collecting body 21 unwound from the unwinding roll 22a is fed in a state where one surface faces the container 2, and is wound up by the winding roll 22b.

  The suction mechanism 23 includes a duct 23a, a fan 23b disposed in the duct 23a, a fan control unit 23c for controlling the fan 23b, a duct inlet opening 23d provided at an end of the duct 23a on the collector 21 side, and a duct 23a. The dispersion medium / solvent recovery part 23e is connected to the outlet side opening of Here, it is preferable that the inner diameter of the duct opening 23d is substantially equal to the inner diameter of the outlet side opening 8d of the cylindrical body 8.

Next, the operation of the nanofiber manufacturing apparatus having the above configuration will be described.
By rotating the container 2 in which the raw material liquid F is supplied through the raw material liquid supply pipe 15 by the motor 13, a centrifugal force is applied to the raw material liquid F so as to assist the discharge from the discharge hole 2a. Further, by applying a high voltage to the annular electrode 3 by the power source 7, a charge having a polarity opposite to that applied to the annular electrode 3 is induced at least in the opening of the discharge hole 2 a of the container 2.
As a result, an electric field is generated between the container 2 and the annular electrode 3, and the raw material liquid F is charged by the charge induced in the container 2 by the voltage applied to the annular electrode 3. Due to this electric field, a force is applied to the charged raw material liquid F toward the annular electrode 3.

  The raw material liquid F is discharged radially from the discharge hole 2a toward the annular electrode 3 by the electric field and centrifugal force. The raw material liquid F discharged from the discharge holes 2a evaporates the dispersion medium or solvent while flying in the air, and the charge density gradually increases. When the coulomb force in the repulsive direction inside the raw material liquid F exceeds its surface tension, an electrostatic explosion occurs. By repeating this, the raw material liquid F is subdivided into fibers, and the fibrous substance F1 (nanofibers) ) Is formed.

  On the other hand, the raw material liquid F discharged from the discharge hole 2a or the fibrous substance F1 formed therefrom is substantially perpendicular to the discharge direction (the radial direction of the container 2) due to the air flow generated by the blower 4 or the like. The direction is changed to a different direction (the axial direction of the container 2) and transferred toward the collector 5. At this time, the flow path of the raw material liquid F and the like discharged from the upstream discharge hole 2a by the air flow adjusting member 41 becomes the annular electrode 3 side, and the path of the raw material liquid F and the like discharged from the downstream discharge hole 2a travels. The airflow is adjusted so that is on the container 2 side. Thereby, the path | route which the fibrous substance F1 discharge | released from each discharge hole 2a located in a line in the direction of an airflow follows is disperse | distributed to the radial direction of the container 2. FIG. As a result, for example, even if the container 2 is rotated at a higher rotational speed and a larger amount of the raw material liquid F is discharged from the discharge hole 2a, the raw material liquids F and the like overlap and the quality of the manufactured nanofiber is deteriorated. Can be prevented. In the collector 5, the fibrous substance F1 is deposited with high density and evenly on the collection body 21 fed at a moderate speed by the feeding mechanism 22, and a nonwoven fabric is formed.

  In the first embodiment, a voltage is applied to the annular electrode 3 by the power source 7 to induce charges on the peripheral surface of the container 2, but a voltage is applied to the container 2 by the power source 7 to It is good also as what induces an electric charge to electrode 3.

  Here, the polymer material contained in the raw material liquid F is polypropylene, polyethylene, polystyrene, polyethylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, poly-m-phenylene terephthalate, poly-p-phenylene isophthalate, polyfluoride. Vinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyvinyl chloride, vinylidene chloride-acrylate copolymer, polyacrylonitrile, acrylonitrile-methacrylate copolymer, polycarbonate, polyarylate, polyester carbonate, nylon, aramid, polycaprolactone , Polylactic acid, polyglycolic acid, collagen, polyhydroxybutyric acid, polyvinyl acetate, polypeptide, etc. Can, at least one is used selected from these. However, the polymer materials that can be included in the raw material liquid F are not limited to these, and even existing substances that have been newly recognized as being suitable as raw materials for nanofibers or that will be developed in the future. Any material that is recognized as being suitable as a raw material for nanofibers can be suitably used.

  The dispersion medium or solvent for dispersing or dissolving the polymer material is methanol, ethanol, 1-propanol, 2-propanol, hexafluoroisopropanol, tetraethylene glycol, triethylene glycol, dibenzyl alcohol, 1,3- Dioxolane, 1,4-dioxane, methyl ethyl ketone, methyl isobutyl ketone, methyl-n-hexyl ketone, methyl-n-propyl ketone, diisopropyl ketone, diisobutyl ketone, acetone, hexafluoroacetone, phenol, formic acid, methyl formate, ethyl formate, Propyl formate, methyl benzoate, ethyl benzoate, propyl benzoate, methyl acetate, ethyl acetate, propyl acetate, dimethyl phthalate, diethyl phthalate, dipropyl phthalate, methyl chloride, ethyl chloride , Methylene chloride, chloroform, o-chlorotoluene, p-chlorotoluene, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, trichloroethane, dichloropropane, dibromoethane, dibromopropane, methyl bromide, ethyl bromide , Propyl bromide, acetic acid, benzene, toluene, hexane, cyclohexane, cyclohexanone, cyclopentane, o-xylene, p-xylene, m-xylene, acetonitrile, tetrahydrofuran, N, N-dimethylformamide, pyridine, water and the like are suitable. It can illustrate as a thing and at least 1 sort (s) chosen from these is used. However, the dispersion medium or solvent for dispersing or dissolving the polymer material is not limited to these, and even if it is an existing substance, the suitability of the polymer material as a dispersion medium or solvent in the electrospinning method is new. Or materials that will be developed in the future and can be suitably used as dispersion media or solvents can be suitably used.

The raw material liquid F can be mixed with an inorganic solid material. Examples of the inorganic solid material that can be mixed include oxides, carbides, nitrides, borides, silicides, fluorides, and sulfides. From the viewpoint of heat resistance, workability, etc., it is preferable to use an oxide. Examples of the oxide include Al ₂ O ₃ , SiO ₂ , TiO ₂ , Li ₂ O, Na ₂ O, MgO, CaO, SrO, BaO, B ₂ O ₃ , P ₂ O ₅ , SnO ₂ , ZrO ₂ , K _2. O, Cs ₂ O, ZnO, Sb ₂ O ₃ , As ₂ O ₃ , CeO ₂ , V ₂ O ₅ , Cr ₂ O ₃ , MnO, Fe ₂ O ₃ , CoO, NiO, Y ₂ O ₃ , Lu ₂ O ₃ , Yb ₂ O ₃ , HfO ₂ , Nb ₂ O _{5 and the} like can be exemplified, and at least one selected from these can be used. However, the inorganic solid material mixed in the raw material liquid F is not limited to these.

  Although the mixing ratio of the polymer material and the dispersion medium or solvent depends on the kind of the polymer material, the mixing ratio is preferably 50 to 99% by weight.

<Embodiment 2>
The second embodiment of the present invention will be described below with reference to the drawings. The second embodiment is a modification of the first embodiment, and only the parts different from the first embodiment will be described below.
FIG. 4 is a schematic diagram of a main part of the nanofiber manufacturing apparatus according to Embodiment 2 of the present invention. FIG. 5 is a plan view of the annular member of the apparatus of FIG.

  In the nanofiber manufacturing apparatus according to the second embodiment, a hollow annular member 42 and a partition plate 44 are arranged at the boundary portion between the guide body 20 and the annular electrode 3, and the blower 4 is omitted.

  The annular member 42 is a member having a hollow portion 42 a whose outer diameter is slightly larger than the outer diameter of the annular electrode 3 and whose inner diameter is slightly smaller than the inner diameter of the annular electrode 3. Gas (for example, air) is supplied to the hollow portion 42a at a predetermined pressure through a conduit 43 by a pump (not shown). Further, as shown in FIG. 5, an ejection hole 42 b for ejecting the gas in the hollow portion 42 a toward the space between the annular electrode 3 and the container 2 is formed on one end surface (the end surface on the annular electrode 3 side) of the annular member 42. It is perforated so as to be arranged in an arc shape at a predetermined pitch. As shown in FIG. 4, the ejection holes 42 b are provided so as to be arranged in an arc shape immediately inside the inner peripheral surface of the annular electrode 3. Therefore, the gas ejected from the ejection hole 42b is directed from the position near the inner peripheral surface of the annular electrode 3 toward the outer peripheral surface of the container 2 as shown by arrows H11, H12, H13, H14, H15, and H16 in FIG. Flowing to spread.

  As a result, the raw material liquid F released from the discharge hole 2a on the most upstream side advances in the axial direction of the container 2 only when it reaches the vicinity of the annular electrode 3 and receives the deflection force of the airflow jetted from the jet hole 42b. Direction is deflected. On the other hand, the raw material liquid F discharged from the discharge hole 2a on the most downstream side is deflected in the axial direction of the container 2 immediately after being discharged from the discharge hole 2a, receiving the deflection force of the air flow indicated by the arrow H13. Is done. Thereby, the path | route which the fibrous substance F1 discharge | released from each discharge | emission hole 2a arranged in a line in the direction of an air flow can be disperse | distributed to the radial direction of the container 2. FIG. Further, according to the second embodiment, the same effect as in the first embodiment can be obtained by supplying a smaller amount of gas.

  In the second embodiment, in order to obtain the same effect as in the first embodiment with a smaller amount of gas, the gas is ejected from the ejection holes 42b arranged in an annular shape. . However, the present invention is not limited to this. Instead of the ejection hole 42b, an ejection groove (shown by an annular broken line 42c in the figure) is provided on one end face of the annular member 42. Gas may be ejected from the ejection groove. In this case, there is a possibility that the required amount of gas may be increased, but a uniform air flow without deviation can be sent around the container 2 as compared with the case of injecting the gas from the ejection hole 42b.

<Embodiment 3>
The third embodiment of the present invention will be described below with reference to the drawings. The third embodiment is a modification of the first embodiment, and only the parts different from the first embodiment will be described below. FIG. 6 is an enlarged cross-sectional view of a main part of the nanofiber manufacturing apparatus according to Embodiment 3 of the present invention. FIG. 7 is a perspective view of the vicinity of the container 2 with the annular electrode removed from the apparatus of FIG.
In the nanofiber manufacturing apparatus according to the third embodiment, a circular plate member 45 and a cylindrical member 46 are arranged at the boundary between the guide body 20 and the annular electrode 3. The plate member 45 is a substantially circular member provided with an insertion hole 45a through which the container 2 is inserted in the axial direction at the center. The airflow generated by the blower 4 or the like flows into the space between the container 2 and the annular electrode 3 through the gap between the edge of the insertion hole 45 a and the outer peripheral surface of the container 2.

  The cylindrical member 46 is a trumpet-shaped member whose diameter increases from the upstream side to the downstream side of the airflow, and the container 2 is loosely fitted in the hollow portion in the axial direction. The airflow flowing through the gap between the plate member 45 and the container 2 is the axis of the rear container 2 that spreads in the radial direction of the container 2 along the outer peripheral surface of the cylindrical member 46 as indicated by the broken arrows H21 to H26. It flows parallel to the direction. As a result, the raw material liquid F discharged from the discharge hole 2a on the most upstream side is deflected in a direction so as to draw a gentle curve before reaching the vicinity of the annular electrode 3, When it reaches, the advancing direction becomes parallel to the axial direction of the container 2. Further, the raw material liquid F released from the discharge hole 2a on the most downstream side is released from the discharge hole 2a, and then the direction of traveling by the air flow is deflected in the axial direction of the container 2 at a relatively early stage. Thereby, the path | route which the raw material liquid F etc. which are discharged | emitted from each discharge hole 2a arranged in a line in the direction of an air current can disperse | distribute to the radial direction of the container 2. FIG.

  In each of the above-described embodiments, the discharge holes 2 a are formed at equal intervals on the peripheral wall of the container 2 at a portion facing the annular electrode 3 so as to form a row parallel to the axial direction of the container 2. Arranged. However, the present invention is not limited to this, and the discharge holes 2a form at least one row, and the raw material liquid F exiting each discharge hole 2a is deflected in a predetermined direction, and the discharge holes 2a form the row. Even when the released raw material liquid and the flight trajectory overlap, the above-described special effect of the present invention is exhibited.

  In the above embodiment, the cylindrical container is rotated at a predetermined speed. In such a case, the raw material liquid F exiting the discharge hole 2a has a flight trajectory that varies depending on the arrangement of the discharge holes 2a due to the centrifugal force due to rotation and the deflection due to the airflow. In all cases where the trajectory of the released raw material liquid F overlaps in flight, the above-described special effects can be exhibited by applying the present invention.

<Embodiment 4>
The fourth embodiment of the present invention will be described below with reference to the drawings. The fourth embodiment is a modification of the first embodiment, and only the parts different from the first embodiment will be described below. FIG. 8 is a schematic view of a part of a nanofiber manufacturing apparatus according to Embodiment 4 of the present invention in cross section.
The nanofiber manufacturing apparatus of the fourth embodiment includes a plurality of nozzles 2e as discharge holes for discharging the raw material liquid F so as to form at least one row on one surface (lower surface in the figure) of the rectangular box-shaped container 2G. In addition, the raw material liquid F is pumped from the raw material liquid reservoir 32 at a predetermined pressure by the raw material liquid pump 33 into the container 2G. The lower surface of the container 2G is opposed to the grounded flat electrode 3G, and the container 2G is connected to the positive electrode of the high-voltage power source 7 whose negative electrode is grounded.

  With the above configuration, the positively charged raw material liquid F is discharged toward the electrode 3G from the nozzle 2e of the container 2G. In addition, the blower 4 is arranged between the lower surface of the container 2G and the electrode 3G so as to blow air in parallel with the lower surface of the container 2G, and the air flow path by the blown air is defined. A guide body (not shown) similar to that shown in FIG. In FIG. 8, the fact that the raw material liquid F has a positive charge is indicated by a circled symbol of + (plus).

  The raw material liquid F discharged from the nozzle 2e toward the electrode 3G is deflected in the direction substantially perpendicular to the discharge direction by the air flow. Here, on the upstream side of the airflow nozzle 2e, an airflow adjustment member 41G is disposed so as to have a predetermined gap between the electrode 3G and the airflow adjustment member 41G.

As shown in FIG. 8, the airflow generated by the blower 4 or the like is once accelerated when passing through the gap, and then is indicated by broken arrows H31 to H33 from a position near the electrode 3G toward the lower surface of the container 2G. It flows into the space between the container 2G and the electrode 3G while spreading as shown.
As a result, the raw material liquid F or the like discharged from the nozzle 2e on the most upstream side of the airflow advances straight without receiving the deflection force of the airflow until it reaches the vicinity of the electrode 3G, and reaches the vicinity of the electrode 3G. For the first time, upon receiving the deflection force, the traveling direction is deflected in the axial direction of the container 2. On the other hand, the raw material liquid F or the like discharged from the discharge hole 2a on the most downstream side of the airflow is subjected to the deflection force immediately after the discharge by the airflow as indicated by arrows H32 and H33. The traveling direction is deflected in a direction substantially perpendicular to the discharge direction. In this way, each of the discharge holes is arranged such that the direction in which the raw material liquid F and the like discharged from the nozzle 2e on the downstream side of the airflow advances in a position closer to the peripheral surface of the container 2G is deflected in a direction substantially perpendicular to the discharge direction. The traveling path of the raw material liquid F released from 2a is dispersed.

  Accordingly, since the raw material liquid F and the like discharged from the nozzle 2e on the upstream side of the air flow and the raw material liquid F and the like discharged from the downstream nozzle 2e are prevented from overlapping, they are discharged from the nozzle 2e on the most downstream side. This prevents the charging of the raw material liquid F from being inhibited, and the discharge of the raw material liquid F from the most downstream nozzle 2e from being inhibited.

  As described above, the raw material liquid F or the like whose direction of travel is deflected passes through the inside of the rectangular cylinder 8G and is arranged at the outlet (not shown) of the cylinder 8G in the same manner as in the first embodiment. It is deposited on the collector 21 and collected. As shown in the fourth embodiment, the present invention is not limited to the case where the container has a cylindrical shape, and has at least one row of discharge holes (nozzles 2e) and applies a predetermined pressure to the raw material liquid F. In the case where the raw material liquid F is discharged and the raw material liquid F is charged and a fiber is generated by electrostatic explosion and deflected in a predetermined direction, the raw material liquid F is adjusted by adjusting the air flow by the air flow adjusting means. By distributing the path through which the liquid F travels in the discharge direction, the same effects as in the above embodiments can be obtained.

Examples of the present invention will be described below. The present invention is not limited to the following examples.
On the peripheral wall of a substantially cylindrical container 2 having an outer diameter of 60 mm and an inner diameter of 59 mm, six discharge holes 2 a are arranged in the axial direction of the container 2 to form one row, and 18 rows are arranged in the circumferential direction of the container 2. A total of 108 discharge holes 2a were formed. At this time, the pitch of the discharge holes 2a in the circumferential direction of the container 2 was 10 mm. The pitch of the discharge holes 2a in the axial direction of the container 2 was also 10 mm.
Then, three types of containers 2 were prepared with the diameter of the discharge hole 2a being three types of 0.20 mm, 0.30 mm, and 0.50 mm.

  Using a nanofiber manufacturing apparatus (hereinafter referred to as an example apparatus) having the same configuration as FIG. 1 incorporating these three types of containers 2, the container 2 was rotated at various rotational speeds for 20 minutes to manufacture nanofibers. . Here, the diameter of the annular electrode 3 was 400 mm, the voltage of the power source 7 was 60 KV, the negative electrode was connected to the annular electrode 3, and the positive electrode was grounded. The feeding amount of the collecting body 21 was 5 mm / min. The polymer material used for the raw material liquid F was polyvinyl alcohol (PVA), water was used as the solvent, and the amount of the solvent was 90% and mixed with the polymer material.

  Here, Example 1 is a nanofiber manufactured by the Example device incorporating the container 2 having a diameter of the discharge hole 2a of 0.20 mm. In addition, a nanofiber manufactured by an example apparatus incorporating the container 2 having a diameter of the discharge hole 2a of 0.30 mm is referred to as Example 2. Further, a nanofiber manufactured by an example device incorporating the container 2 having a diameter of the discharge hole 2a of 0.50 mm is referred to as Example 3.

  On the other hand, the three types of containers 2 are incorporated into a nanofiber manufacturing apparatus (hereinafter referred to as a comparative apparatus) in which the airflow adjusting member 41 is deleted from the nanofiber manufacturing apparatus of FIG. 1, and the containers 2 are rotated at various rotational speeds for 20 minutes. The nanofiber was manufactured. Here, a nanofiber manufactured by a comparative apparatus incorporating a container 2 having a diameter of the discharge hole 2a of 0.20 mm is referred to as Comparative Example 1. Further, a nanofiber manufactured by a comparative apparatus incorporating a container 2 having a diameter of the discharge hole 2a of 0.30 mm is referred to as a comparative example 2. Further, a nanofiber manufactured by a comparative apparatus incorporating a container 2 having a discharge hole 2a having a diameter of 0.50 mm is referred to as Comparative Example 3.

  And about the said Examples 1-3 and Comparative Examples 1-3, the manufactured nanofiber is observed with a microscope, and it is investigated whether the high quality nanofiber which the lump of a polymeric substance is not mixed is manufactured. did. The result is shown in FIG. In the figure, the upper limit of the number of rotations of the container 2 capable of producing the high-quality nanofiber is indicated by a white double-headed arrow for each diameter of the discharge hole 2a.

As shown in FIG. 8, in Examples 1 to 3, compared with Comparative Examples 1 to 3 in which the diameter of the discharge hole 2 a is the same, in the range of the high rotation speed of the container 2, the mass of the polymer substance is reduced. High quality nanofibers with no contamination could be produced. This is because in Examples 1 to 3, since the path of the raw material liquid F and the like discharged from the discharge holes 2a arranged in the axial direction of the container 2 is dispersed in the radial direction of the container 2, the container 2 is rotated at a high speed. This is considered to be because the charging of the raw material liquid F discharged from the downstream discharge hole 2a was not hindered even when a large amount of the raw material liquid F was discharged from the discharge hole 2a by rotating by a number. It is done.
Thus, according to the nanofiber manufacturing apparatus of the present invention, it was confirmed that high-quality nanofibers can be manufactured with higher productivity.

According to the nanofiber manufacturing apparatus and manufacturing method of the present invention, when manufacturing nanofibers using the electrospinning method, it is possible to manufacture high-quality nanofibers with high productivity.

It is the side view which made the cross section a part which shows schematic structure of the nanofiber manufacturing apparatus which concerns on Embodiment 1 of this invention. FIG. 2 is an enlarged view of a portion of the apparatus of FIG. It is a perspective view of the vicinity part of a container of the state which removed the annular electrode from the apparatus of FIG. It is the schematic of the principal part of the nanofiber manufacturing apparatus which concerns on Embodiment 2 of this invention. FIG. 5 is a plan view of an annular member of the apparatus of FIG. 4. It is sectional drawing to which the principal part of the nanofiber manufacturing apparatus concerning Embodiment 3 of this invention was expanded. It is a perspective view of the vicinity part of a container of the state which removed the annular electrode from the apparatus of FIG. It is the side view which made a part of principal part of the nanofiber manufacturing apparatus concerning Embodiment 4 of the present invention a section. It is a graph which shows the Example and comparative example of this invention. It is the schematic of an example of the conventional nanofiber manufacturing apparatus. It is the side view which made the principal part of another conventional nanofiber manufacturing apparatus the cross section.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Manufacturing apparatus 2 Container 2a Release hole 3 Annular electrode 4 Blower 5 Collector 7 Power supply 21 Collecting body 23 Suction mechanism 41 Airflow adjustment member 42 Annular member 43 Conduit 45 Plate member 46 Cylindrical member

Claims (8)

A plurality of discharge holes for discharging the raw material liquid containing a polymeric material which is held inside to the outside, is formed in the outer wall, a container opening of at least the discharge hole is formed from the conductor,
An electrode disposed opposite to the discharge hole of the container;
A power source for applying a potential difference between the electrode and the container so as to charge the raw material liquid discharged from the discharge hole of the container;
A force application mechanism that applies force to the raw material liquid so as to discharge the raw material liquid from the discharge hole toward the electrode;
A transfer means for transferring the raw material liquid discharged from the discharge hole or the fibrous material generated by electrostatic explosion from the raw material liquid in a direction substantially perpendicular to the discharge direction of the raw material liquid by being deflected by an air current;
Collecting means for collecting the fibrous material transferred by the transfer means,
Said transfer means, viewed including the air flow adjusting means each of said raw material liquid or the fibrous material which is discharged from the discharge hole to adjust the air flow to disperse the path proceeding is deflected by the air flow in the discharge direction,
The container has a cylindrical shape with at least one end closed,
The discharge hole is formed in the peripheral wall of the container,
The force application mechanism includes a rotation drive mechanism that rotates the container,
The electrode includes a substantially cylindrical conductor disposed coaxially around the container,
The air flow adjusting means includes a gap for allowing the air flow to flow into a space between the peripheral wall of the container in which the discharge hole is formed and the electrode, and the discharge of the air flow. A nanofiber manufacturing apparatus including a substantially circular plate member arranged on the upstream side of a hole . The plate member has a through hole through which the container center is loosely fitted, the nano-fiber manufacturing apparatus according to claim 1. A plurality of discharge holes for discharging a raw material liquid containing a polymer material held inside to the outside, and a container in which at least an opening of the discharge hole is formed from a conductor;
An electrode disposed opposite to the discharge hole of the container;
A power source for applying a potential difference between the electrode and the container so as to charge the raw material liquid discharged from the discharge hole of the container;
A force application mechanism that applies force to the raw material liquid so as to discharge the raw material liquid from the discharge hole toward the electrode;
A transfer means for transferring the raw material liquid discharged from the discharge hole or the fibrous material generated by electrostatic explosion from the raw material liquid in a direction substantially perpendicular to the discharge direction of the raw material liquid by being deflected by an air current;
Collecting means for collecting the fibrous material transferred by the transfer means,
The transfer means includes airflow adjusting means for adjusting the airflow so that the path of the raw material liquid or the fibrous material discharged from each of the discharge holes is deflected by the airflow and dispersed in the discharge direction,
The container has a cylindrical shape with at least one end closed,
The discharge hole is formed in the peripheral wall of the container,
The force application mechanism includes a rotation drive mechanism that rotates the container,
The electrode includes a substantially cylindrical conductor disposed coaxially around the container,
The transfer means includes gas supply means for supplying a gas at a predetermined pressure,
The air flow adjusting means is
The gas supplied by the gas supply means includes ejection means for unloading position or al-injection in the vicinity of the inner peripheral surface of the electrode in the space between the wall and the electrode of the container the discharge hole is formed , device for production of nanofibres. The ejection means is
An annular shape having a hollow portion that temporarily holds the gas supplied by the gas supply means, and at least one ejection hole or ejection groove for ejecting the gas held in the hollow portion provided at one end portion The nanofiber manufacturing apparatus according to claim 3, comprising a member. A plurality of discharge holes for discharging a raw material liquid containing a polymer material held inside to the outside, and a container in which at least an opening of the discharge hole is formed from a conductor;
An electrode disposed opposite to the discharge hole of the container;
A power source for applying a potential difference between the electrode and the container so as to charge the raw material liquid discharged from the discharge hole of the container;
A force application mechanism that applies force to the raw material liquid so as to discharge the raw material liquid from the discharge hole toward the electrode;
A transfer means for transferring the raw material liquid discharged from the discharge hole or the fibrous material generated by electrostatic explosion from the raw material liquid in a direction substantially perpendicular to the discharge direction of the raw material liquid by being deflected by an air current;
Collecting means for collecting the fibrous material transferred by the transfer means,
The transfer means includes airflow adjusting means for adjusting the airflow so that the path of the raw material liquid or the fibrous material discharged from each of the discharge holes is deflected by the airflow and dispersed in the discharge direction,
The container has a cylindrical shape with at least one end closed,
The discharge hole is formed in the peripheral wall of the container,
The force application mechanism includes a rotation drive mechanism that rotates the container,
The electrode includes a substantially cylindrical conductor disposed coaxially around the container,
The air flow adjusting means is
A gap for allowing the airflow to flow into the space between the peripheral wall of the container in which the discharge hole is formed and the electrode is disposed between the outer peripheral surface of the container and is more than the discharge hole of the airflow. A substantially circular plate member disposed on the upstream side;
Disposed in the gap, including a cylindrical member whose diameter increases toward the downstream side from the upstream side of the air flow, the nano-fiber manufacturing apparatus. The nanofiber manufacturing apparatus according to any one of claims 1 to 5, wherein the plurality of discharge holes are distributed in the axial direction of the container. The nanofiber manufacturing apparatus according to claim 6, wherein at least a part of the plurality of discharge holes are arranged in a line in the axial direction of the container. A plurality of discharge holes for discharging a raw material liquid containing a polymer material held inside to the outside, and a container in which at least an opening of the discharge hole is formed from a conductor;
An electrode disposed opposite to the discharge hole of the container;
A power source for applying a potential difference between the electrode and the container so as to charge the raw material liquid discharged from the discharge hole of the container;
A force application mechanism that applies force to the raw material liquid so as to discharge the raw material liquid from the discharge hole toward the electrode;
A transfer means for transferring the raw material liquid discharged from the discharge hole or the fibrous material generated by electrostatic explosion from the raw material liquid in a direction substantially perpendicular to the discharge direction of the raw material liquid by being deflected by an air current;
Collecting means for collecting the fibrous material transferred by the transfer means,
The transfer means includes airflow adjusting means for adjusting the airflow so that the path of the raw material liquid or the fibrous material discharged from each of the discharge holes is deflected by the airflow and dispersed in the discharge direction,
The container has a box shape,
The discharge hole is formed in a wall portion of one surface of the container,
The force application mechanism includes a pumping mechanism that pumps the raw material liquid into the container at a predetermined pressure ,
The electrode includes a plate-like conductor disposed to face the one surface of the container,
The airflow adjusting means has a gap for allowing the airflow to flow into the space between the one surface of the container and the electrode, and is upstream of the discharge hole of the airflow. The nanofiber manufacturing apparatus containing the substantially square board member distribute | arranged to the side .

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