JP4830992B2 - Method and apparatus for producing nanofiber and polymer web - Google Patents

Description

  The present invention relates to a nanofiber made of a polymer material and a method and apparatus for producing a highly porous polymer web on which the nanofiber is deposited.

  Conventionally, an electrospinning (charge-induced spinning) method is known as a method for producing a nanofiber having a submicron-scale diameter made of a polymer material. In the conventional electrospinning method, by supplying a polymer solution to a needle-shaped nozzle to which a high voltage is applied, the polymer solution that flows out linearly from the needle-shaped nozzle is charged, and the polymer solution As the solvent evaporates, the distance between the charged charges decreases and the acting Coulomb force increases, and when the Coulomb force exceeds the surface tension of the linear polymer solution, the linear polymer solution explodes. A phenomenon of stretching occurs, and this phenomenon called electrostatic explosion is repeated as primary, secondary, and in some cases, tertiary, etc., so that nanofibers made of a polymer with a submicron diameter are produced. .

  By depositing the nanofibers thus manufactured on an electrically grounded substrate, a three-dimensional thin film having a three-dimensional network can be obtained, and by forming it thicker, it has a submicron network. A highly porous web can be produced. The highly porous webs thus produced can be suitably applied to filters, battery separators, polymer electrolyte membranes and electrodes of fuel cells, etc., and by applying this highly porous web made of nanofibers, respectively. It can be expected to dramatically improve the performance.

  However, in the conventional electrospinning method, only a plurality of nanofibers are produced from the tip of one nozzle, and therefore, even if an attempt is made to produce a highly porous polymer web, the productivity does not increase, so it cannot be realized. was there. Therefore, as a method for producing a polymer web by producing a large amount of nanofibers, a method using a plurality of nozzles has been proposed (for example, see Patent Document 1).

  The configuration of the polymer web manufacturing apparatus described in Patent Document 1 will be described with reference to FIG. 16. The liquid polymer substance in the barrel 43 is fed by the pump 44 to the spinning section 42 having a plurality of nozzles 41. The high voltage generator 45 applies a high voltage of 5 to 50 kV to the nozzle 41 and deposits the fiber discharged from the nozzle 41 on the collector 46 that is grounded or charged to a polarity different from that of the nozzle 41. At the same time, the formed web is transferred by the collector 46 to produce a polymer web. In addition, a charge distribution plate 47 is disposed near the tip of the nozzle 41 to minimize electrical interference between the nozzles 41, and a high voltage is applied between the collector 46 and the charged fiber is directed toward the collector 46. It is also described that an electric field is applied.

  Further, as shown in FIGS. 17A and 17B, the spinning unit 42 is not provided with a plurality of single nozzles, but is provided with a plurality of multi-nozzles 41A each including a plurality of nozzles 41. It is also disclosed that a plurality of nanofibers are generated from each nozzle 41A.

In the melt spinning method, a method using centrifugal force is conventionally known (for example, see Patent Document 2). This is a method for producing a fiber by spinning with a centrifugal force by putting a polymer solution in a rotating body having a large number of spinning holes on the peripheral side surface and rotating at high speed. However, this method can only produce fibers having a diameter larger than that of sub-micron-order nanofibers, and there are technical difficulties in producing nanofibers. Therefore, as a method for producing nanofibers, the above-described electrospinning (charge-induced spinning) method has been researched and developed for many years.
JP 2002-201559 A JP 58-114106 A

  However, in order to produce a polymer web with higher productivity with the configuration shown in FIGS. 16 and 17, the arrangement interval of the nozzles 41 in the spinning section 42 and the nozzles 41 in each multi-nozzle 41 </ b> A is reduced, and the unit area per unit area is reduced. When the number of nozzles is increased, as shown in FIG. 18, since the high molecular substances flowing out from the nozzles 41 are charged with the same polarity, they repel each other as indicated by arrows, Outflow from the nozzle 41 is hindered, the outflow direction from the nozzle 41 in the peripheral portion is directed outward, the nanofiber deposition distribution on the collector 46 is extremely small in the central portion, and is concentrated in the peripheral portion. There is a problem that a uniform polymer web cannot be produced.

  Further, when the charge distribution plate 47 is disposed in the vicinity of the tip of the nozzle 41, as shown in FIG. 19, the electric interference between the nozzles 41 is reduced and an electric field E from the charge distribution plate 47 toward the collector 46 is formed. As a result, the action of accelerating the polymer substance flowing out from each nozzle 41 toward the collector 46 is obtained, so that the deposition distribution of nanofibers in the central portion and the peripheral portion as compared with the case of FIG. However, there is a problem in that the arrangement pattern of the nozzles 41 is projected as it is onto the deposition distribution, so that the effect of uniformizing the deposition distribution is not exhibited.

  Further, when the arrangement density of the nozzles 41 is increased, there is a possibility that the fibers contact each other in a state where the solvent does not sufficiently evaporate, and the fibers are welded to each other. There is a problem that there is a possibility that corona discharge may occur and fibers may not be formed.

  In addition, when a large number of nozzles 41 are provided, it is difficult to uniformly supply the liquid polymer material to the nozzles 41, which causes a problem that the apparatus configuration becomes complicated and the equipment cost increases. is there. Further, in order to cause an electrostatic explosion on the liquid polymer material flowing out from the nozzle 41, it is necessary to concentrate electric charges. For this reason, each nozzle 41 is formed in a thin and long shape, but a large number of thin and long shapes. There is a problem that maintenance for always maintaining the nozzle 41 in an appropriate state is extremely difficult.

  SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and it is possible to produce nanofibers and polymer webs that can produce nanofibers and polymer webs using the same in a highly productive, uniform and simple configuration. It is an object to provide a method and apparatus.

Method for producing nanofibers of the present invention has a plurality of small holes, at least in rotary vessel said eyelet near has conductivity, and supplying a polymer solution obtained by dissolving a polymer material in a solvent, high The relationship between the viscosity of the molecular solution, the rotation speed of the rotating container, and the diameter of the nanofiber to be generated is measured in advance, the viscosity of the polymer solution is measured, and the centrifugal force required for electrostatic spinning is applied based on the relationship. When the viscosity of the polymer solution is high, the rotation speed of the rotating container is increased, and when the viscosity of the polymer solution is low, the rotation speed of the rotating container is decreased. By rotating the rotating container in a controlled manner, the linear polymer solution is caused to flow out from the plurality of small holes and stretched, and an electric field is applied to the linear polymer solution that has flowed out of the small holes to For electrostatic explosion accompanying evaporation And a step of generating nanofibers made of polymeric material was further stretched. In the present invention, in order to apply an electric field to the linear polymer solution flowing out from the small hole of the rotating container, the rotating container and an object or member constituting a field for generating nanofibers between the rotating container and A high potential difference may be given between the two. For example, when the object or member constituting the field for generating nanofibers with the rotating container is a member such as the earth or a collector grounded to the earth, the rotating container is positive or negative with respect to the ground potential. What is necessary is just to apply a high voltage. In addition, when a positive or negative high voltage with respect to the ground potential is applied to a member such as a collector constituting a field for generating nanofibers with the rotating container, the rotating container may be grounded. Alternatively, a high voltage having a polarity opposite to the high voltage applied to the collector may be applied to the rotating container. Needless to say, the small hole is not limited to a hole formed directly in the peripheral wall of the rotating container, but may be configured by a nozzle that is integrally mounted or integrally formed with the peripheral wall of the rotating container. Further, at least the vicinity of the small hole of the rotating container only needs to have conductivity, but of course, the entire rotating container may have conductivity.

  According to the above configuration, the polymer solution flows out linearly from the plurality of small holes of the rotating container by the action of centrifugal force, and the electric charge is charged by the applied electric field. At that time, first, the polymer solution stably flows out of the small hole and is stretched by the action of the centrifugal force. Also, a phenomenon has been discovered that electric field interference hardly occurs by rotating the rotating container. The reason for this is that when the polymer solution flows out from the adjacent small holes, it flows out by centrifugal force, so that the flowing linear directions are not parallel to each other but spread radially, causing electric field interference. It is considered difficult. In this way, since it is not affected by electric field interference, even if the small holes are arranged at a high density, the hole is surely and effectively stretched. After that, the charged linear polymer solution is further stretched by centrifugal force to reduce the diameter and evaporate the solvent, so that the charged charge is concentrated and the Coulomb force exceeds the surface tension. A primary electrostatic explosion occurs and is stretched explosively. Further, after that, the solvent evaporates, and similarly, a secondary electrostatic explosion occurs and the film is stretched explosively. In some cases, a third electrostatic explosion or the like occurs and the film is stretched. In this way, nanofibers made of a polymer material having a submicron diameter are efficiently produced from a linear polymer solution flowing out from a plurality of small holes.

  In addition, since the small holes can be arranged with high density as described above, a large amount of nanofibers can be efficiently manufactured with a simple and compact configuration. In addition, since the polymer solution that has flowed out of the small holes is first stretched by centrifugal force, it is not necessary to make the small holes extremely small, and the polymer solution can stably flow out from each small hole, and the nanofibers that can be generated can be made uniform. There are also benefits. Therefore, it is only necessary to provide a small hole in the rotating container, it can be manufactured easily and inexpensively, and maintenance can be easily performed even if a large number of small holes are provided.

  The rotating container is preferably a cylindrical container having a plurality of small holes on the peripheral surface and rotating around an axis. This makes it possible to produce a large amount of nanofibers uniformly from the entire circumference of the cylindrical container at the same time, ensuring high productivity, and reducing the equipment cost due to the simple shape and configuration. Can do.

  Preferably, the rotational speed of the rotating container is controlled based on the viscosity of the polymer solution contained in the rotating container. Thereby, the necessary centrifugal force can be applied to the polymer solution according to the viscosity of the polymer solution without changing the rotating container, so that the nanofiber can be produced reliably and efficiently. When the viscosity is high, the diameter of the nanofibers to be produced is large, and when the viscosity is low, the diameter is thin.When the viscosity is high, the rotation speed of the rotating container is increased, and the viscosity is increased. When it becomes low, control is performed to slow down the rotation speed.

  Further, the radial distance between the rotation axis of the rotating container and the small hole may be determined based on the viscosity of the polymer solution accommodated in the rotating container. Then, the nanofiber can be manufactured reliably and efficiently by applying a necessary centrifugal force to the polymer solution according to the viscosity of the polymer solution without changing the rotation speed of the rotating container extremely.

  The method for producing a polymer web of the present invention includes a step of depositing nanofibers produced by the above-described method for producing nanofibers, and depositing nanofibers produced in large quantities as described above. Thus, a highly porous polymer web can be produced with high productivity.

  Preferably, a conductive collector is disposed at a distance from the rotating container, a high voltage is applied between the rotating container and the collector, and nanofibers are deposited on the collector. Then, the charged nanofibers move toward the collector and are deposited on the collector, so that a polymer web can be efficiently formed. Note that the collector may have a function of sequentially transferring the polymer web deposited thereon.

The nanofiber manufacturing apparatus of the present invention includes a rotating container that is rotatably supported and has a plurality of small holes at a distance from the rotation axis in the radial direction, and at least the vicinity of the small holes is conductive, and a polymer. The relationship between the viscosity of the solution, the rotation speed of the rotating container, and the diameter of the nanofiber to be generated is measured in advance, the viscosity of the polymer solution is measured, and the centrifugal force necessary for electrostatic spinning is applied based on the relationship. By calculating the optimum rotation speed, the rotation speed of the rotation container is increased when the viscosity of the polymer solution is high, and the rotation speed of the rotation container is decreased when the viscosity of the polymer solution is low. Rotation driving means for rotationally driving the container, high voltage generating means for applying a high voltage to the rotating container, polymer solution supply means for supplying a polymer solution in which a polymer substance is dissolved in a solvent in the rotating container, With rotational drive means A controller that controls the voltage generating means and the polymer solution supply means is provided. While the rotating container is rotated at a predetermined speed by the controller, the polymer solution is supplied into the rotating container and a high voltage is applied to the rotating container. It is what you do. With this configuration, the above-described method for producing nanofibers can be carried out to achieve the effect.

Another nanofiber manufacturing apparatus of the present invention includes a rotating container that is rotatably supported and has a plurality of small holes at a radial distance from the rotation axis, and at least the vicinity of the small holes is conductive. , Measure the relationship between the viscosity of the polymer solution, the rotation speed of the rotating container and the diameter of the nanofibers generated in advance, measure the viscosity of the polymer solution, and determine the centrifugal force required for electrostatic spinning based on the relationship. By calculating the optimum rotation speed for the action, if the viscosity of the polymer solution is high, the rotation speed of the rotation container is increased, and if the viscosity of the polymer solution is low, the rotation speed of the rotation container is decreased. Rotation driving means for rotating the rotary container, a conductive collector disposed between the rotary container and a high voltage generating means for applying a high voltage between the rotary container and the collector, , Rotating container A polymer solution supply means for supplying a polymer solution in which a polymer substance is dissolved in a solvent, and a control unit for controlling the rotation drive means, the high voltage generation means, and the polymer solution supply means. A polymer solution is supplied into the rotating container while rotating the rotating container at a predetermined speed, and a high voltage is applied between the rotating container and the collector. Specifically, when a high voltage is applied to the rotating container and the collector is grounded or a high voltage opposite in polarity to the rotating container is applied, the rotating container is grounded and a positive or negative high voltage is applied to the collector. There are cases. The same effect can be obtained by this configuration.

  The rotating container is preferably constituted by a cylindrical container having a plurality of small holes on the peripheral surface, and provided with means for controlling the amount of the polymer solution accommodated in the cylindrical container to be constant. As a result, a large amount of nanofibers can be manufactured uniformly from the entire circumference of the cylindrical container at the same time. As a result, high productivity can be ensured, and the shape and configuration are simple, resulting in lower equipment costs. Can be achieved. In addition, by controlling the amount of the polymer solution in the rotating container to a predetermined amount, a uniform centrifugal force can be applied to the polymer solution in the rotating container to produce uniform nanofibers.

  In the polymer web production apparatus of the present invention, the nanofiber produced by the another nanofiber production apparatus is deposited on a collector having a planar spread to produce a polymer web. The nanofibers produced as described above are deposited on the collector, and a polymer web can be produced efficiently.

  It is preferable to provide sheet material moving means for moving the sheet material on which the nanofibers adhere and deposit on the collector at a predetermined speed. If it does so, the sheet | seat in which the polymeric web of required thickness was formed can be manufactured continuously.

  According to the nanofiber and polymer web manufacturing method and apparatus of the present invention, the polymer solution flows out linearly from the plurality of small holes of the rotating container by the action of centrifugal force, and the electric field is charged by the applied electric field, After that, the film is further stretched by centrifugal force and the diameter of the solvent is reduced as the solvent evaporates. The electric charge is concentrated, and the film is stretched explosively by the primary electrostatic explosion. Is generated and explosively stretched to efficiently produce and deposit nanofibers made of a polymer material having a submicron diameter from a linear polymer solution flowing out from a plurality of small holes. Thus, the polymer web can be produced with high productivity.

  Hereinafter, each embodiment of the manufacturing method and apparatus of the nanofiber and polymer web of the present invention will be described with reference to FIGS.

(First embodiment)
First, a first embodiment of the method and apparatus for producing a polymer web of the present invention will be described with reference to FIGS.

  FIG. 1 is a diagram for explaining the principle of a nanofiber manufacturing method applied to the polymer web manufacturing method of the present embodiment. In FIG. 1, reference numeral 1 denotes a cylindrical container having a diameter of 50 to 500 mm as a rotating container, and is driven to rotate at a rotational speed of 30 to 3000 rpm as indicated by an arrow R around its axis. A polymer solution 2 in which a polymer substance, which is a nanofiber material, is dissolved in a solvent is supplied into the rotating container 1 from one end thereof.

  Polymer materials constituting the polymer solution 2 include polypropylene, polyethylene, polystyrene, polyethylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, poly-m-phenylene terephthalate, poly-p-phenylene isophthalate, polyfluoride. Vinylidene, polyvinylidene fluoride-hexafluoropropylene copolymer, polyvinyl chloride, polyvinylidene chloride-acrylate copolymer, polyacrylonitrile, polyacrylonitrile-methacrylate copolymer, polycarbonate, polyarylate, polyester carbonate, nylon, aramid, poly Examples include caprolactone, polylactic acid, polyglycolic acid, collagen, polyhydroxybutyric acid, polyvinyl acetate, and polypeptide. , At least one selected from these are used, but the invention is not particularly limited thereto.

Solvents that can be used are 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, and at least one selected from these can be used. The present invention is not limited.

  In addition, an inorganic solid material can be mixed in the polymer solution. Examples of the inorganic solid material include oxides, carbides, nitrides, borides, silicides, fluorides, sulfides, and the like. However, it is preferable to use an oxide from the viewpoints of heat resistance and workability. The oxides include Al2O3, SiO2, TiO2, Li2O, Na2O, MgO, CaO, SrO, BaO, B2O3, P2O5, SnO2, ZrO2, K2O, Cs2O, ZnO, Sb2O3, As2O3, CeO2, V2O3, Cr2O3, Cr2O3, Cr2O3 , 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, but is not particularly limited thereto.

  The rotary container 1 is configured such that a high voltage of 1 to 100 kV is applied by the high voltage generator 3 and a high voltage is applied to the polymer solution 2 accommodated therein. A large number of small holes 4 having a diameter of about 0.1 to 2 mm are formed on the peripheral surface of the cylindrical container 1 at a pitch interval of several mm. When the cylindrical container 1 is driven to rotate at high speed, centrifugal force is applied to the polymer solution 2. As a result, the polymer solution 2 flows out linearly from each small hole 4, and the linear polymer solution 2 is stretched by the action of centrifugal force to produce a thin polymer linear body 5. The polymer linear body 5 is charged by receiving an action of an electric field formed around the rotating container 1 to which a high voltage is applied.

  The polymer linear body 5 is further greatly stretched by the action of centrifugal force and the solvent is evaporated to reduce the diameter of the polymer linear body 5, thereby concentrating the charged charges. When the Coulomb force exceeds the surface tension of the polymer solution, a primary electrostatic explosion 6 is generated and stretched explosively. Thereafter, the solvent further evaporates, and similarly a secondary electrostatic explosion 7 is generated and stretched explosively. In some cases, a third electrostatic explosion or the like is further generated and stretched, so that a high diameter having a submicron diameter is obtained. Nanofibers made of molecular materials are efficiently produced. The primary electrostatic explosion 6 extends explosively while spiraling into a conical shape with the explosion start point as the apex, and the secondary electrostatic explosion 7 is basically the same, but various By being influenced by the disturbance factor, it is explosively stretched in a complicated manner, and FIG. 1 schematically shows the manner.

  The polymer web manufacturing apparatus of this embodiment to which the nanofiber manufacturing method is applied has a basic configuration as shown in FIGS. The cylindrical container 1 is supported so as to be rotatable around its axis by support members 8 erected on both sides in the axis direction. Specifically, both ends of the central shaft body 9 penetrating the shaft core portion of the cylindrical container 1 are fixed to the support member 8, and the cylindrical container 1 can be rotated around the central shaft body 9 via the bearing 10. It is supported. A drive motor 11 is disposed on the inner surface of the support member 8 facing one end of the cylindrical container 1, and a drive pulley 12 fixed to the output shaft thereof and a driven pulley 13 fixed to the outer peripheral portion of one end face of the cylindrical container 1. A belt 14 is wound between the cylindrical container 1 and the cylindrical container 1 is rotationally driven in the direction of arrow R in FIG. 2 by the rotational driving means 15 comprising the driving motor 11, the driving pulley 12, the driven pulley 13 and the belt 14. It is configured. The small holes 4 of the cylindrical container 1 may be directly perforated on the peripheral wall of the cylindrical container 1, but as shown in FIG. It is preferable that the small hole 4 is formed by forming the nozzle hole.

  Between the support members 8 and 8, a planar collector 16 having conductivity is disposed so as to face the lower portion of the cylindrical container 1 with an appropriate distance with a planar spread, and is electrically grounded. A high voltage generating means 3 is interposed between the collector 16 and the cylindrical container 1 to apply a high voltage to the cylindrical container 1 and to apply a large potential difference between the cylindrical container 1 and the collector 16 to charge the nanofibers. Moves toward the collector 16 and deposits thereon. Instead of grounding the collector 16, a voltage having a polarity opposite to that of the cylindrical container 1 may be applied. As the high voltage generating means 3, one having an output voltage of 1 to 100 kV and capable of being arbitrarily switched on and off as required by the switch 3a is suitable. In addition, it is preferable that the cylindrical container 1 is energized from the high voltage generating hand 3 to the cylindrical shaft 1 from a fixed portion with respect to the central shaft body 9 of the bearing 10 so that the central shaft body 9 has an insulating structure. In addition, although the example which applies a positive voltage to the cylindrical container 1 to the high voltage generation means 3 was shown, a negative voltage may be sufficient and the polarity of the electric charge charged in that case will be reversed. Alternatively, the cylindrical container 1 may be grounded and a high voltage may be applied to the collector 16.

  The central shaft body 9 is formed of a hollow shaft whose one end is closed, and the hollow portion constitutes a supply passage 17 for the polymer solution 2, and a material supply disposed at an appropriate interval in the axial direction in the lower portion thereof. A predetermined amount of the polymer solution 2 is supplied almost uniformly into the cylindrical container 1 from the mouth 18. Therefore, the material supply port 18 may be set so that the opening area gradually increases from the opening end side of the supply passage 17 toward the closing end side. Further, as shown in FIG. 5, a plurality of supply pipes 19 are inserted and arranged in the supply passage 17, and the outlet openings 19 a of the supply pipes 19 are respectively positioned corresponding to the material supply ports 18 to supply each material. The polymer solution 2 may be supplied to the mouth 18 more reliably and evenly.

  A preferred configuration example of the polymer solution supply means 20 that supplies the polymer solution 2 toward the supply passage 17 of the central shaft body 9 is shown in FIG. In FIG. 6, a polymer substance 2 dissolved in the solvent is supplied from a solution tank 21 containing a polymer solution 2 to an insulating intermediate container 23 sealed by a gear pump 22. By supplying compressed air from a compressed air source (not shown) into the insulating intermediate container 23 via an air regulator 24 and pressing the liquid surface of the polymer solution 2, the polymer solution 2 is insulated from the insulating intermediate container 23. Is supplied to the supply passage 17 or the supply pipe 19 through the feed pipe 25 inserted in the bottom of the pipe. If comprised in this way, it can prevent reliably that the high voltage applied to the cylindrical container 1 leaks through the polymer solution 2 to the gear pump 22 side. In addition, when insulation between the cylindrical container 1 is ensured, the polymer solution 2 may be simply supplied directly from the solution tank 21 to the supply passage 17 or the supply pipe 19 by the gear pump 22. .

  Moreover, as an arrangement form of the small holes 4 formed on the outer peripheral surface of the cylindrical container 1, as shown in FIG. Since all the distances between 4 and 4 are equal intervals, it is preferable that the nanofibers can be uniformly ejected on the surface of the polymer linear body 5. Moreover, as shown in FIG.7 (b), you may arrange | position in a matrix form at equal intervals in the circumferential direction and the axial direction.

  In the above configuration, a predetermined amount of the polymer solution 2 is supplied into the cylindrical container 1 by the polymer solution supply means 20 and a predetermined high voltage is applied to the cylindrical container 1 from the high voltage generating means 3. A high voltage is applied to the polymer solution 2 accommodated in the cylindrical container 1. In this state, when the cylindrical container 1 is rotated at high speed by the rotation driving means 15, the polymer solution 2 flows out linearly from the plurality of small holes 4 as described above, and the polymer linear body 5 is formed. The polymer linear body 5 is greatly stretched by the action of centrifugal force and is charged by the action of the electric field around the cylindrical container 1. Thereafter, the film is further stretched by centrifugal force to reduce the diameter and evaporate the solvent, thereby causing a primary electrostatic explosion and stretching explosively. Thereafter, the solvent further evaporates, and similarly, a secondary electrostatic explosion occurs, and the film is further expanded explosively. In some cases, a third electrostatic explosion or the like occurs and the film is extended to flow out from the plurality of small holes 4. A nanofiber made of a polymer material having a submicron diameter is manufactured from the polymer linear body 5, and the manufactured nanofiber having a charge moves toward the collector 16 and is deposited on the collector 16. Thus, a highly porous polymer web is produced with high productivity.

  Here, since the polymer linear body 5 formed by flowing out from the small hole 4 of the cylindrical container 1 is first largely stretched by centrifugal force, the diameter of the small hole 4 can be set to about 0.1 to 2 mm. The small hole 4 does not need to be formed in an elongated nozzle and is not affected by electric field interference because it is not necessary to make it extremely small and it is not necessary to concentrate electric charges unlike the case where electrostatic explosion is first generated. Therefore, even if it is arranged at a high density, it can be surely and effectively stretched, so that a large amount of nanofibers can be efficiently produced with a simple and compact configuration. In addition, a large amount of nanofibers can be manufactured uniformly from the entire circumference of the cylindrical container 1 at a time, so that high productivity can be secured and the shape and configuration are simple, so that the equipment cost is reduced. be able to. Further, since it is not necessary to form the small holes 4 long, it is only necessary to simply provide the small holes 4 on the outer peripheral wall of the cylindrical container 1, and it can be easily and inexpensively manufactured. It is.

  The rotation driving means 15 is configured to be able to control the rotation speed of the cylindrical container 1 based on the viscosity of the polymer solution 2 accommodated in the cylindrical container 1, thereby the viscosity of the polymer solution 2. Accordingly, the necessary centrifugal force can be applied to the polymer solution 2 to reliably and efficiently produce nanofibers. When the viscosity is high, the diameter of the produced nanofibers is large, and when the viscosity is low, the diameter is small. Therefore, when the viscosity is high, the rotation speed of the rotating container 1 is increased and the viscosity is increased. When it becomes low, control is performed to slow down the rotation speed. Corresponding to the composition of the polymer solution, the relationship between the viscosity, the rotation speed and the diameter of the nanofibers can be measured in advance by experiment. The speed can be calculated, and nanofibers having a desired uniform diameter can be generated by controlling the speed so as to be the rotational speed. Also, the diameter of the cylindrical container 1 itself may be determined based on the viscosity of the polymer solution 2 accommodated in the rotating container 1, and the viscosity of the polymer solution 2 can be changed without extremely changing the rotation speed. The necessary centrifugal force can be applied according to the above.

(Second Embodiment)
Next, a second embodiment of the method and apparatus for producing a polymer web of the present invention will be described with reference to FIG. In the following description of the embodiment, the same components as those in the preceding embodiment are denoted by the same reference numerals, description thereof is omitted, and only differences will be mainly described.

  In the above embodiment, an example in which the central shaft body 9 is fixed to the support member 8 and the cylindrical container 1 is rotatably supported via the bearing 10 with respect to the central shaft body 9 has been described. As shown in FIG. 8, the cylindrical container 1 and the central shaft body 9 are fixed, and both end portions of the central shaft body 9 are rotatably supported by the support member 8 via bearings 10. Correspondingly, the rotation driving means 15 is configured by connecting the output shaft of the drive motor 11 to one end of the central shaft body 9 via the speed reducer 26, and the speed reducer 26 is supported by the mounting member 27 at the support member 8. The drive motor 11 is attached to a mounting bracket 27 by a mounting bracket 28. Further, the high voltage generating means 3 is connected to the fixed side of the bearing 10 disposed on the support member 8, and the rotating side of the bearing 10 and the cylindrical container 1 are connected by the conductive member 29, and the central shaft body 9 is connected. Is configured to have insulating properties.

  According to the present embodiment, only the rotational drive mechanism of the cylindrical container 1 is different, and the configuration of the main part is the same as that of the first embodiment, so that the same effect can be obtained. In this embodiment, since the central shaft body 9 rotates, a rotary joint (not shown) is interposed between the polymer solution supply means 20 and the central shaft body 9.

(Third embodiment)
Next, a third embodiment of the method and apparatus for producing a polymer web of the present invention will be described with reference to FIG.

  In the above embodiment, an example in which a high voltage generated by the high voltage generating unit 3 and having a high potential with respect to the ground potential is applied to the cylindrical container 1 and the collector 16 is set to the ground potential has been described. The positive or negative high voltage generated by the high voltage generating means 3 is applied to the collector 16, and the cylindrical container 1 is grounded via the conductive member 29 and the bearing 10.

  Also in this embodiment, the polymer linear body 5 is formed by flowing out of the polymer linear body 5 from the cylindrical container 1 to which a high voltage is applied positively or negatively relative to the collector 16. The charged polymer solution is charged by an electric field between the cylindrical container 1 and the collector 16 to cause electrostatic explosion, and nanofibers are efficiently manufactured in the same manner as described above. And flow toward the collector 16 to deposit a polymer web on the collector 16. In this embodiment, a high voltage is applied only to the collector 16 with respect to the ground potential, and the cylindrical container 1 to which the rotation driving means 15 and the polymer solution supply means 20 are connected is set to the ground potential. There is an advantage that it can be easily secured and safety can be secured with a simple configuration.

(Fourth embodiment)
Next, a fourth embodiment of the method and apparatus for producing a polymer web of the present invention will be described with reference to FIGS.

  In the embodiment described above, an example in which a predetermined amount of the polymer solution 2 is supplied into the cylindrical container 1 based on the production amount of the polymer web has been described. The amount of the molecular solution 2 is detected and the operation of the polymer solution supply means 20 is controlled according to the detection result so that a substantially constant amount of the polymer solution 2 is accommodated in the rotating container 1. Yes.

  In FIG. 10, in this embodiment, the configuration of the first embodiment is used as a basic configuration, and a protrusion 30 projecting downward toward the inner periphery of the cylindrical container 1 is provided on the fixed central shaft body 9. When the amount of the polymer solution 2 contained in the container reaches a predetermined amount, the liquid surface of the polymer solution 2 comes into contact with the protrusions 30. When the polymer solution 2 comes into contact with the protrusions 30, the rotational resistance of the cylindrical container 1 increases, and the motor current flowing through the drive motor 11 that is driven and controlled to rotate the cylindrical container 1 at a predetermined rotational speed is generated. Therefore, the amount of the polymer solution 2 reaches a predetermined amount by detecting this motor current.

  Therefore, as shown in FIG. 11, motor current detection means 31 for detecting the motor current of the drive motor 11 in the rotation drive means 15 is provided, and the detection signal is input to the control section 32, and the control section 32 provides a polymer. The operation of the solution supply unit 20 is controlled. In FIG. 11, the control unit 32 includes a control program stored in advance in the storage unit 33, various control data input from the operation unit 34, and input signals from various sensors (not shown) installed in each unit. The high voltage generating means 3, the rotation driving means 15, and the polymer solution supplying means 20 are controlled based on the operation command from the operation section 34, and the operation state and the like are displayed on the display section 35. .

  In the above configuration, when the polymer solution 2 is supplied into the cylindrical container 1 by the polymer solution supply means 20, the motor current increases as the amount of the polymer solution 2 increases as shown in FIG. Gradually increases, and when the liquid surface of the polymer solution 2 starts to contact the projection 30 through the state at the time T1, the motor current increases rapidly, and at the time T2, the amount of the polymer solution 2 becomes L1, When the protrusion 30 is always in contact with the polymer solution 2, the motor current reaches C1. Therefore, the operation of the polymer solution supply means 20 is turned off, and the supply of the polymer solution 2 is stopped. Thereafter, with the production of the polymer web, the amount of the polymer solution 2 in the cylindrical container 1 gradually decreases, and at time T3, the amount of the polymer solution 2 becomes L2 and the protrusion 30 becomes the polymer solution 2. Since the motor current decreases to C2 when it is separated from, the polymer solution 2 is supplied by the polymer solution supply means 20 at this time, and thereafter, the operation at the time T2 and the time T3 is repeated, so that the inside of the cylindrical container 1 The amount of the polymer solution 2 is always controlled to be almost constant.

  According to the present embodiment, the amount of the polymer solution 2 in the cylindrical container 1 can be controlled to a predetermined amount with a simple and inexpensive configuration in which the simple protrusions 30 are provided as described above. A constant centrifugal force is applied to the polymer solution 2 in the container 1, the centrifugal force acting on the polymer solution 2 pushed out from the small hole 4 of the cylindrical container 1 is constant, and the polymer solution 2 flows out uniformly in a linear shape. The nanofiber and the polymer web can be produced uniformly.

(Fifth embodiment)
Next, a fifth embodiment of the method and apparatus for producing a polymer web of the present invention will be described with reference to FIGS.

  In the above embodiment, nanofibers are deposited on the collector 16, the polymer web formed on the collector 16 is collected, or a member for forming the polymer web is disposed on the collector 16, and the polymer web is In the present embodiment, as shown in FIG. 13, the sheet material moving means 37 that moves the sheet material 36 on which the nanofibers adhere and deposit along the collector 16 at a predetermined speed is shown. Is provided. If comprised in this way, the sheet | seat in which the polymer web of required thickness was formed can be manufactured continuously.

  In another example of this embodiment, as shown in FIG. 14, a plurality (four in the figure) of collectors 16 and sheet material moving means 37 are equally arranged so as to surround the periphery of the cylindrical container 1, and the cylindrical container The nanofibers emitted and generated from the entire circumference of the periphery of 1 are directed toward each collector 16, and a polymer web is continuously formed on the sheet material 36 that is moved at a predetermined speed by the sheet material moving means 37. It is configured to do. By comprising in this way, a some polymeric web can be manufactured simultaneously with the nanofiber discharge-formed by the perimeter of the cylindrical container 1. FIG.

(Sixth embodiment)
Next, a sixth embodiment of the polymer web manufacturing method and apparatus of the present invention will be described with reference to FIG.

  In the above embodiment, as shown in FIG. 13, the nanofibers formed around the cylindrical container 1 are collected and deposited only by a single collector 16 arranged on one side, or as shown in FIG. 14. In the present embodiment, a plurality of collectors 16 are arranged around and collected and deposited all around, but in this embodiment, as shown in FIG. The reflective electrode 38 charged with the same polarity as the charged charge of the cylindrical container 1 is disposed in a region excluding the region where the collector 16 is disposed around the cylindrical container 1. The reflective electrode 38 is preferably a net-like electrode so that the evaporated solvent can be smoothly diffused to the outside, and the shape of the reflective electrode 38 is such that the reflection direction is directed to the collector 16 regardless of the position of reflection. Designed to.

  According to the present embodiment, the nanofibers emitted and generated from the entire circumference of the cylindrical container 1 are repelled and reflected by the same-polarity charge of the reflective electrode 38, and are surely directed toward the collector 16. Since the material is deposited on the moving sheet material 36, the polymer web can be efficiently produced in a short time with the nanofibers formed and released around the entire circumference of the cylindrical container 1.

  In the description of each of the above embodiments, an example of the cylindrical container 1 that is driven to rotate about the axis as a rotating container has been shown. However, the present invention is not necessarily limited to the cylindrical container 1. The polymer solution 2 can be formed into any shape as long as it has a function of forming the polymer linear body 5 by rotating and rotating the polymer solution 2 from the small hole 4 by centrifugal force.

  According to the method and apparatus for producing nanofibers and polymer webs of the present invention, nanofibers having a submicron diameter can be efficiently produced from a linear polymer solution flowing out from a plurality of small holes provided in a rotating container. Moreover, since it can be deposited to produce a polymer web, a highly porous web suitable for use in filters, battery separators, polymer electrolyte membranes and electrodes of fuel cells, etc. can be produced with high productivity. It can be suitably used for this.

The principle explanatory drawing of the nanofiber manufacturing method applied to the manufacturing method of the polymeric web in the 1st Embodiment of this invention. The perspective view which shows schematic structure of the manufacturing apparatus of the polymer web in the embodiment. The longitudinal cross-sectional front view which shows schematic structure of the manufacturing apparatus of the polymer web in the embodiment. The perspective view which shows the other structural example of the rotation container in the embodiment. Sectional drawing which shows the other structural example of the uniform supply structure of the polymer solution in the rotation container in the embodiment. The partial cross section block diagram of an example of the polymer solution supply means in the embodiment. Explanatory drawing of the example of arrangement | positioning of the small hole in the cylindrical container of the embodiment. The longitudinal cross-sectional front view which shows schematic structure of the manufacturing apparatus of the polymer web in the 2nd Embodiment of this invention. The longitudinal cross-sectional front view which shows schematic structure of the manufacturing apparatus of the polymer web in the 3rd Embodiment of this invention. The longitudinal cross-sectional front view which shows schematic structure of the manufacturing apparatus of the polymer web in the 4th Embodiment of this invention. The block diagram which shows the control structure of the embodiment. Explanatory drawing of the control operation | movement of the polymer solution amount in the same embodiment. The longitudinal side view which shows schematic structure of the manufacturing apparatus of the polymeric web in the 5th Embodiment of this invention. The longitudinal side view which shows the other structural example of the manufacturing apparatus of the polymer web in the same embodiment. The longitudinal side view which shows schematic structure of the manufacturing apparatus of the polymer web in the 6th Embodiment of this invention. The schematic block diagram of the manufacturing apparatus of the polymer web of a prior art example. The principal part structure of the other structural example of the prior art example is shown, (a) is a front view, (b) is a partially enlarged bottom view. Explanatory drawing of the problem in the conventional example. Explanatory drawing of the further problem in the conventional example.

Explanation of symbols

1 Cylindrical container (rotary container)
2 Polymer Solution 3 High Voltage Generating Means 4 Small Hole 5 Polymer Linear Body 6 Primary Electrostatic Explosion 7 Secondary Electrostatic Explosion 15 Rotation Driving Means 16 Collector 17 Supply Path 18 Material Supply Port 20 Polymer Solution Supply Means 30 Projection 31 Motor current detection means 32 Control part 36 Sheet material 37 Sheet material movement means 38 Reflective electrode

Claims (8)

Supplying a polymer solution obtained by dissolving a polymer substance in a solvent into a rotating container having a plurality of small holes and at least the vicinity of the small holes is conductive;
The relationship between the viscosity of the polymer solution, the rotation speed of the rotating container, and the diameter of the nanofibers to be generated is measured in advance, and the viscosity of the polymer solution is measured and the centrifugal force required for electrostatic spinning is applied based on the relationship. When the viscosity of the polymer solution is high, the rotation speed of the rotating container is increased, and when the viscosity of the polymer solution is low, the rotation speed of the rotating container is decreased. By rotating and rotating the rotating container to flow out a linear polymer solution from a plurality of small holes, and extending,
A step of generating a nanofiber made of a polymer material by applying an electric field to a linear polymer solution flowing out from a small hole and further stretching it by an electrostatic explosion caused by evaporation of the solvent and the solvent. The manufacturing method of nanofiber. Rotating container has a plurality of small holes in the circumferential surface, the nanofibers method according to claim 1, characterized in that the cylindrical container to rotate about its axis. A method for producing a polymer web, comprising the step of depositing nanofibers produced by the method for producing nanofibers according to claim 1. A conductive collector is placed at a distance from the rotating container,
Apply a high voltage between the rotating container and the collector,
4. The method for producing a polymer web according to claim 3, further comprising a step of depositing nanofibers on the collector. A rotating container that is rotatably supported and has a plurality of small holes at a distance in a radial direction from the rotation axis, and at least the vicinity of the small holes has conductivity.
The relationship between the viscosity of the polymer solution, the rotation speed of the rotating container, and the diameter of the nanofibers to be generated is measured in advance, and the viscosity of the polymer solution is measured and the centrifugal force required for electrostatic spinning is applied based on the relationship. When the viscosity of the polymer solution is high, the rotation speed of the rotating container is increased, and when the viscosity of the polymer solution is low, the rotation speed of the rotating container is decreased. A rotation drive means for rotating the rotary container;
High voltage generating means for applying a high voltage to the rotating container;
A polymer solution supply means for supplying a polymer solution in which a polymer substance is dissolved in a solvent in a rotating container;
A control unit for controlling the rotation drive means, the high voltage generation means, and the polymer solution supply means;
An apparatus for producing a nanofiber or polymer web, wherein a polymer solution is supplied into a rotating container and a high voltage is applied to the rotating container while rotating the rotating container at a predetermined speed by a control unit. A rotating container that is rotatably supported and has a plurality of small holes at a distance in a radial direction from the rotation axis, and at least the vicinity of the small holes has conductivity.
The relationship between the viscosity of the polymer solution, the rotation speed of the rotating container, and the diameter of the nanofibers to be generated is measured in advance, and the viscosity of the polymer solution is measured and the centrifugal force required for electrostatic spinning is applied based on the relationship. When the viscosity of the polymer solution is high, the rotation speed of the rotating container is increased, and when the viscosity of the polymer solution is low, the rotation speed of the rotating container is decreased. A rotation drive means for rotating the rotary container;
A conductive collector disposed at a distance from the rotating container;
High voltage generating means for applying a high voltage between the rotating container and the collector;
A polymer solution supply means for supplying a polymer solution in which a polymer substance is dissolved in a solvent in a rotating container;
A control unit for controlling the rotation drive means, the high voltage generation means, and the polymer solution supply means;
An apparatus for producing nanofibers, wherein a polymer solution is supplied into a rotating container while a rotating container is rotated at a predetermined speed by a controller, and a high voltage is applied between the rotating container and a collector. A polymer web produced by depositing nanofibers produced by the nanofiber production device according to claim 6 on a collector having a planar spread. Manufacturing equipment. 8. The apparatus for producing a polymer web according to claim 7, further comprising sheet material moving means for moving the sheet material on which the nanofibers adhere and deposit on the collector at a predetermined speed.

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