JP5226558B2 - Nanofiber manufacturing apparatus and nanofiber manufacturing method - Google Patents

Description

  The present invention relates to a nanofiber manufacturing apparatus and a nanofiber manufacturing method, and more particularly to a nanofiber manufacturing apparatus and a nanofiber manufacturing method capable of improving maintenance performance and improving nanofiber production efficiency.

  An electrospinning (charge-induced spinning) method is known as a method for producing a filamentous (fibrous) material (nanofiber) made of a polymer material or the like and having a submicron-scale diameter.

  The electrospinning method is a method in which a raw material liquid in which a polymer substance or the like is dispersed or dissolved in a solvent is discharged (discharged) into a space by a nozzle or the like, and a charge is applied to the raw material liquid for charging. And the nanofiber is manufactured when the raw material liquid in flight electrically extends in space.

  A more specific description of the electrospinning method is as follows. That is, the raw material liquid charged and discharged into the space gradually evaporates the solvent while flying through the space. As a result, the volume of the raw material liquid in flight gradually decreases, but the charge imparted to the raw material liquid remains in the raw material liquid. As a result, the charge density of the raw material liquid in flight through the space gradually increases. Since the solvent continues to evaporate, the charge density of the raw material liquid further increases, and the polymer solution explodes when the repulsive Coulomb force generated in the raw material liquid exceeds the surface tension of the raw material liquid. A phenomenon of linear stretching (hereinafter referred to as electrostatic stretching phenomenon) occurs. This electrostatic stretching phenomenon occurs one after another in the space in a geometric series, so that a nanofiber made of a polymer having a submicron diameter is manufactured.

When the electrospinning method as described above is employed, it is more efficient to make the raw material liquid flow out as thinly as possible in the space in order to manufacture a thin nanofiber. In addition, when the portion from which the raw material liquid is discharged is sharp, charges are more likely to concentrate, and the raw material liquid can be charged efficiently. Furthermore, in order to discharge the raw material liquid in a stable flight direction, a hole having a certain length is preferable. Therefore, as described in Patent Document 1, the nanofiber manufacturing apparatus has conventionally ejected the raw material liquid into the space from the tip of a thin nozzle.
Special table 2007-532790 gazette

  When nanofibers are manufactured using the nanofiber manufacturing apparatus described above, if the nanofiber manufacturing apparatus is used for a long time, the resin used as the raw material for the nanofibers may solidify and block the holes for discharging the nanofibers. is there. In particular, in such a case, not only the production efficiency of the nanofibers is reduced, but also the manufactured nanofibers are collected in a biased state, so that the masses blocking the holes are periodically removed. Maintenance is required.

  However, in the case of a thin nozzle or the like, it may be difficult to remove the lump of resin from the hole for discharging the raw material liquid.

  This invention is made | formed in view of the said problem, and aims at provision of the nanofiber manufacturing apparatus which can improve maintainability, maintaining the quality of the nanofiber manufactured.

  In order to achieve the above object, the nanofiber manufacturing apparatus according to the present invention is a nanofiber manufacturing apparatus for manufacturing nanofibers by stretching a raw material liquid in a space, up to the tip where the raw material liquid flows into the space, An outflow body having a flow path for guiding the raw material liquid, and a flow path portion that forms an opening along the flow path, a supply device that supplies the raw material liquid to the outflow body, and the supplied raw material liquid to the tip A gas flow generation device that generates a gas flow and a charging device that charges the raw material liquid are provided.

  As a result, the raw material liquid can flow out into the space at a time without allowing the raw material liquid to pass through the narrow hole. Moreover, since the raw material liquid is guided to the flow path portion that opens along the flow path and flows out into the space, the lump can be easily removed at the time of maintenance even if the resin hardens in the middle. Therefore, maintainability can be improved while maintaining or improving the quality of the nanofiber, and the production efficiency of the nanofiber can be improved.

  Moreover, it is preferable that the said flow-path part is a groove | channel provided in the said outflow body.

  This groove makes it possible to guide not only the raw material liquid but also the gas flow, and facilitates the proper flow of the raw material liquid. Further, for example, the raw material liquid can be allowed to flow into the space as a plurality of thin flows by flowing the raw material liquid in a plurality of grooves. Therefore, it is possible to arbitrarily control the quality of the manufactured nanofiber.

  Moreover, it is preferable that the said outflow body is provided with the protrusion part sharpened at the front-end | tip.

  As a result, the charge can be concentrated on the protruding portion, and the raw material liquid flowing out along the protrusion can be efficiently charged. Therefore, the charge density of the raw material liquid is increased, the electrostatic stretching phenomenon occurs at an early stage, and it is possible to produce nanofibers with high quality that occur in multiple stages.

  In particular, by providing a protrusion at a position corresponding to the groove, the shape of the raw material liquid flowing out into the space can be controlled and the charge density of the raw material liquid can be improved. It can be manufactured.

  The tip of the outflow body has a cylindrical shape, the flow path portion is on the inner surface of the cylindrical shape, the opening opens toward the inside of the cylindrical shape, and the charging device It is preferable to provide an annular charging electrode surrounding the tip of the outflow body.

  According to this, the pressure of the gas flow which flowed inward of the cylindrical shape can be increased, and the raw material liquid can be thinned (thinned). In addition, the positional relationship between the outflow body and the charging electrode disposed in the vicinity of the outflow body can be made equal. Therefore, the raw material liquid 300 can be uniformly charged, and the quality of the manufactured nanofiber can be stabilized.

  Further, it is preferable that the diameter of the effluent gradually decreases toward the tip.

  According to this, it is possible to further increase the pressure of the gas flow at the portion where the raw material liquid 300 flows out, and to improve the quality of the manufactured nanofiber.

  Furthermore, you may provide the drive device which rotates the said outflow body around the said cylindrical-shaped axis | shaft.

  Thereby, the raw material liquid 300 can be made to flow out in a uniform state, and it becomes possible to improve the stability of the quality of the manufactured nanofibers.

  The tip of the effluent body may have a planar shape.

  According to this, it becomes possible to manufacture nanofibers over a wide range.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a plan view showing an embodiment of a nanofiber manufacturing apparatus with a part cut away.

  As shown in the figure, the nanofiber manufacturing apparatus 100 includes a discharge device 101, a guide body 102, a collection device 103, an attracting device 104, and a gas flow generation device 106.

  Here, the raw material liquid for manufacturing the nanofiber is referred to as a raw material liquid 300, and the manufactured nanofiber is referred to as a nanofiber 301. Since it changes to 301, the boundary between the raw material liquid 300 and the nanofiber 301 is ambiguous and cannot be clearly distinguished.

  The discharge device 101 is a unit that can discharge the charged raw material liquid 300 and the manufactured nanofiber 301 on a gas flow.

  FIG. 2 is a plan view showing a part of the discharge device by cutting away.

  FIG. 3 is a perspective view showing the appearance of the discharge device.

  As shown in these drawings, the discharge device 101 includes an outflow body 110, a charging device 111, a wind tunnel body 112, a second gas flow generation device 113, and a supply device 141.

  FIG. 4 is a perspective view showing the outflow body.

  In addition, in the same figure, description of the gas flow generator 106 is abbreviate | omitted.

  As shown in the figure, in the case of the present embodiment, the effluent body 110 has a hollow hemispherical shape (dome shape), and has a cylindrical shape with a circular opening at the tip. The outflow body 110 includes a flow path for guiding the raw material liquid and a groove-shaped flow path portion 153 that forms an opening along the flow path to the front end where the raw material liquid 300 flows into the space.

  The outflow body 110 includes a flow path portion 153 and a protruding portion 151.

  The flow path part 153 is a part of the outflow body 110 that forms a flow path for guiding the raw material liquid 300 and forms an opening for applying a gas flow to the raw material liquid 300 existing in the flow path. In the case of this form, the flow path part 153 is formed in the state dug in the groove shape on the inner surface of the outflow body 110.

  In addition, the shape of the flow path part 153 is not limited, For example, it may be a flat surface or a curved surface without a portion engraved in a groove shape. In this case, the opposite side of the outflow body 110 with respect to the plane or curved surface functions as an opening. In addition, the flow path portion 153 adjusts the outflow amount of the raw material liquid 300, and the shape of the flow path portion 153 becomes narrower toward the tip of the outflow body 110, or meanders to loosen the flow of the raw material liquid 300. The shape may be adopted.

  The protrusion 151 is a member that protrudes in a state of being pointed at the tip of the opening of the outflow body 110. In the case of the present embodiment, the protruding portion 151 has a shape that is partially cut so as to extend the flow path portion 153 into a conical shape with a sharp tip 152. Further, the protruding portion 151 has a pointed end 152 in a point shape.

  In particular, the raw material liquid 300 can be guided to the protrusion 151 by providing the protrusion 151 at the tip of the flow path 153 as in the case of the present embodiment. Therefore, the raw material liquid 300 can be brought into contact with the projecting portion 151 where charges are concentrated, and the raw material liquid 300 can be charged efficiently.

  Note that the protrusions 151 do not have to be scattered at the tip of the outflow body 110. For example, a series of protrusions 151 may be provided over the entire periphery of the tip of the outflow body 110. In this case, charges can be easily concentrated by sharpening the tip of the protrusion 151 in a linear shape (edge shape).

  Specifically, it is preferable that the diameter of the tip portion from which the raw material liquid 300 of the effluent 110 flows out is selected from a range of 10 mm to 300 mm. This is because it is difficult to collect nanofibers at a high density if it is too large. On the other hand, if it is too small, it is difficult to flow a large amount of the raw material liquid 300 into the space. Furthermore, it is preferable to employ | adopt the diameter of the front-end | tip part of the outflow body 110 from the range of 20 mm or more and 150 mm or less.

  The outflow body 110 may be gradually reduced in diameter toward the tip.

  The supply device 141 is a device that supplies the raw material liquid 300 to the inner surface of the effluent body 110, and includes a supply unit 142, a supply path 114, and a supply source 144 (see FIG. 1).

  The supply unit 142 is a columnar member that is integrally attached to the outflow body 110, and is a member in which a plurality of supply holes for supplying the raw material liquid 300 are provided in the peripheral portion.

  The supply path 114 is a path for supplying the raw material liquid 300 from the external supply source 144 to the inside of the supply unit 142. In the case of the present embodiment, the supply path 114 is formed of a tubular body.

  The supply source 144 is a device including a tank for storing the raw material liquid 300 and a pump for pumping the raw material liquid 300 at a predetermined pressure.

  In addition, the supply apparatus 141 is not limited to the said Example. For example, the supply unit 142 may be rotated and the raw material liquid 300 may be supplied to the effluent body 110 by centrifugal force.

  FIG. 5 is a cross-sectional view showing the outflow body, the supply unit, and the injection unit.

  The gas flow generation device 106 is a device that generates a gas flow W1 for the raw material liquid 300 supplied from the supply unit 142 to flow to the tip along the flow path portion 153 of the effluent 110, and is a compressor 161 (see FIG. 1). ), A tube 162, and an injection unit 163.

  The compressor 161 is a so-called air compressor capable of boosting air to a predetermined pressure and sending it out. The tube 162 is a tube body that can guide the pressurized air.

  The injection unit 163 is a nozzle that discharges the pressurized air to the surface of the outflow body 110. In the case of the present embodiment, air is jetted from the circular slit so that the jet part 163 spreads evenly on the inner surface of the outflow body 110.

  Note that the gas flow generated by the gas flow generator 106 is not limited to air but may be an inert gas such as nitrogen, or any gas such as superheated steam. The gas flow generator 106 may generate gas flow by supplying gas from a cylinder filled with gas at a high pressure.

  The charging device 111 is a device that charges the raw material liquid 300 by applying an electric charge. In the present embodiment, as shown in FIGS. 1 to 3, the charging device 111 includes a charging electrode 121, a charging power source 122, and a grounding device 123.

  The charging electrode 121 is a member for inducing electric charges to the grounded outflow body 110 when the charging electrode 121 itself becomes a high voltage or a low voltage with respect to the ground. In the case of the present embodiment, the charging electrode 121 is an annular member disposed so as to surround the periphery of the tip of the outflow body 110, and has a circular cross section. When a positive voltage is applied to the charging electrode 121, a negative charge is induced in the outflow body 110, and when a negative voltage is applied to the charging electrode 121, a positive charge is induced in the outflow body 110. .

  In addition, the charging electrode 121 is preferably arranged so that the distance from the protruding portion 151 is closer than any portion of the effluent body 110. In particular, an arrangement that is closest to the tip of the protrusion 151 is preferable. As a result, charge is easily induced at the tip of the protrusion 151.

  The size of the charging electrode 121 needs to be larger than the diameter of the tip portion of the outflow body 110, and the diameter is preferably adopted in the range of 50 mm or more and 1500 mm or less. The shape of the charging electrode 121 is not limited to an annular shape, and may be a polygonal annular shape or a flat plate shape depending on the relationship with the shape of the outflow body 110. Further, the cross-sectional shape of the charging electrode 121 may be not only round but also rectangular.

  The grounding device 123 is a member that is electrically connected to the outflow body 110 and can maintain the outflow body 110 at the ground potential. One end of the grounding device 123 is connected to the outflow body 110, and the other end is connected to the ground.

  The charging power source 122 is a power source that can apply a high voltage to the charging electrode 121. In general, the charging power source 122 is preferably a DC power source. In particular, when the charged polarity of the nanofiber 301 is not affected, the charged nanofiber 301 is used to attract the nanofiber 301 with an electrode to which a reverse polarity potential is applied. Is preferably a DC power supply. When the charging power source 122 is a direct current power source, the voltage applied by the charging power source 122 to the charging electrode 121 is preferably set from a value in the range of 10 KV to 200 KV. When a negative voltage is applied to the charging power source 122, the polarity of the applied voltage becomes negative. In particular, the electric field strength between the outflow body 110 and the charging electrode is important, and the applied voltage is adjusted so that the electric field strength is 1 KV / cm or more in the space where the distance between the charging electrode 121 and the outflow body 110 is the closest. Is preferred.

  If an induction method in which one electrode is grounded is used for the charging device 111 as in the present embodiment, it is possible to charge the raw material liquid 300 while maintaining the effluent 110 at the ground potential. If the outflow body 110 is in a ground potential state, it is not necessary to electrically insulate members such as the rotating shaft body 116 and the driving device 117 connected to the outflow body 110 from the outflow body 110, and the outflow body 110 can be simplified. A structure can be adopted, which is preferable.

  Note that as the charging device 111, a charge may be imparted to the raw material liquid 300 by connecting a power source to the effluent body 110, maintaining the effluent body 110 at a high voltage, and grounding the charging electrode 121.

  The second gas flow generation device 113 is a device for generating a gas flow for transporting the raw material liquid 300 and the manufactured nanofibers 301 that have flowed out of the effluent 110 into the space. The second gas flow generation device 113 is provided at the back of the drive device 117 and generates a gas flow from the drive device 117 toward the tip of the effluent body 110. The second gas flow generation device 113 can generate wind power that can change the direction of the raw material liquid 300 flowing out from the outflow body 110 to the axial direction. In FIG. 2, the gas flow is indicated by arrows. Examples of the second gas flow generator 113 include a blower including an axial fan.

  The second gas flow generating device 113 may be constituted by other blowers such as a sirocco fan. Further, a gas flow may be generated inside the wind tunnel body 112 by a suction device 132 described later. In this case, the nanofiber manufacturing apparatus 100 does not have the second gas flow generation device 113 that actively generates a gas flow, but the gas flow is generated inward of the wind tunnel body 112 or the like by some device. Therefore, it is assumed that the nanofiber manufacturing apparatus 100 includes the second gas flow generation device 113.

  The wind tunnel body 112 is a conduit that guides the gas flow generated by the second gas flow generation device 113 between the charging electrode 121 and the outflow body 110. In the case of the present embodiment, the gas flow guided by the wind tunnel body 112 conveys the raw material liquid 300 that has flowed out of the outflow body 110 while passing through the inside of the charging electrode 121.

  Furthermore, the discharge device 101 includes a heating device 125.

  The heating device 125 is a heating source that heats the gas constituting the gas flow generated by the second gas flow generating device 113. In the case of the present embodiment, the heating device 125 is an annular heater disposed inside the guide body 102 and can heat the gas passing through the heating device 125. By heating the gas flow with the heating device 125, evaporation of the raw material liquid 300 flowing out into the space is promoted, and the nanofiber 301 can be efficiently manufactured.

  FIG. 6 is a perspective view showing the vicinity of the guide body.

  As shown in the figure, the guide body 102 is a wind tunnel that guides the nanofiber 301 that is discharged from the discharge device 101 and conveyed by the gas flow to a predetermined place.

  The diffuser 127 is a conduit that is connected to the guide body 102 and diffuses the high-density nanofibers 301 widely and evenly into a low-density state. The space in which the nanofibers 301 are guided is smoothly and continuously. By expanding, it is a hood-like member that gradually reduces the velocity of the gas flow conveying the nanofiber 301 and the velocity of the nanofiber 301. In the case of the present embodiment, the diffuser 127 has a hood shape that maintains the height of the guide body 102 as it is and gradually expands only the width.

  The collection device 103 is a device for collecting the nanofibers 301 emitted from the guide body 102. In the case of the present embodiment, the collection device 103 includes a member to be deposited 128, a winding device 129, and a member supply device 130.

  The member 128 to be deposited is a member that separates the nanofiber 301 manufactured by the electrostatic stretching phenomenon and conveyed by the gas flow from the gas flow, and deposits only the nanofiber 301. In the case of the present embodiment, the member 128 to be deposited is a thin and flexible long sheet-like member made of a material that can be easily separated from the deposited nanofibers 301, and easily passes a gas flow. It is a net-like member that can collect the nanofibers 301. Specifically, as the member 128 to be deposited, a long cloth made of aramid fibers can be exemplified. Furthermore, it is preferable to apply a Teflon (registered trademark) coating on the surface of the member 128 to be deposited because the peelability when the deposited nanofiber 301 is peeled off from the member 128 to be deposited is improved. Further, the deposition target member 128 is supplied from the member supply device 130 in a state of being wound in a roll shape.

  The winding device 129 is a device that can transfer the member 128 to be deposited. In the case of the present embodiment, the member to be deposited 128 is transported together with the nanofibers 301 to be pulled out from the member supply device 130 while winding the long member to be deposited 128. The winding device 129 can wind up the nanofiber 301 deposited in a nonwoven fabric shape together with the member 128 to be deposited.

  As shown in FIG. 1, the attracting device 104 is a device for attracting the nanofiber 301 to the deposition target member 128. In the case of the present embodiment, the attracting device 104 includes a gas attracting device 143 and an electric field attracting device 133 so that different attracting methods can be performed simultaneously or selectively.

  The gas attracting device 143 is a device that attracts the nanofiber 301 to the deposition target member 128 by sucking a gas flow, and is disposed behind the deposition target member 128. In the case of the present embodiment, the gas attracting device 143 includes a suction device 132 and a concentrating body 131.

  The concentrator 131 is a member that receives the gas flow spread by the diffuser 127 and concentrates the gas flow until reaching the suction device 132, and has a funnel shape opposite to the diffuser 127.

  The suction device 132 is a blower that forcibly sucks the gas flow passing through the member 128 to be deposited. The suction device 132 is a blower such as a sirocco fan or an axial fan, and is a device capable of accelerating a gas flow that has passed through the deposition target member 128 and has a reduced velocity to a high velocity.

  The electric field attracting device 133 is a device that attracts the charged nanofiber 301 to the deposition target member 128 by an electric field, and includes an attracting electrode 134 and an attracting power source 135.

  The attracting electrode 134 is an electrode for generating an electric field for attracting the charged nanofiber 301. In the case of the present embodiment, a metal net capable of passing a gas flow is employed for the attracting electrode 134. The attracting electrode 134 is provided so as to spread over the entire opening of the diffuser 127.

  The attraction power source 135 is a DC power source that can maintain the attraction electrode 134 at a predetermined voltage and polarity. In the case of the present embodiment, the attracting power source 135 is a DC power source that can freely change the voltage and polarity in the range of 0 V (grounded state) to 200 KV or less.

  In addition, although the metal net | network is employ | adopted for the attracting electrode 134 in embodiment, it is not limited to it, The attracting electrode which has the predetermined width | variety length of the width | variety length of the to-be-deposited member 128 may be sufficient. By sucking with the suction device 132, the nanofiber is attracted to the attracting electrode and is attracted to the deposition target member 128 by the gas flow. By doing so, even when using a highly flammable solvent, even if a high-density solvent is used, the concentration of the explosive solvent will not be reached, and the device can be used with confidence. .

  When the charging power source 122 is an AC power source, the attracting power source 135 may be an AC power source.

  The recovery device 105 is a device that can separate and recover the solvent evaporated from the raw material liquid 300 from the gas flow. The recovery device 105 differs depending on the type of solvent used in the raw material liquid 300. For example, a device that recovers a gas by condensing the solvent at a low temperature, a device that adsorbs only the solvent using activated carbon or zeolite, a liquid Examples thereof include an apparatus for dissolving a solvent in the apparatus and a combination of these apparatuses.

  Here, as a polymer substance constituting the nanofiber 301, polypropylene, polyethylene, polystyrene, polyethylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, poly-m-phenylene terephthalate, poly-p-phenylene isophthalate, Polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyvinyl chloride, polyvinylidene chloride-acrylate copolymer, polyacrylonitrile, polyacrylonitrile-methacrylate copolymer, polycarbonate, polyarylate, polyester carbonate, polyamide, aramid , Polyimide, polycaprolactone, polylactic acid, polyglycolic acid, collagen, polyhydroxybutyric acid, polyvinyl acetate Le, polypeptides, and the like, and copolymers can be exemplified. Moreover, the kind selected from the above may be used, and a plurality of kinds may be mixed. Note that the above is an example, and the present invention is not limited to the above polymer substance.

  Solvents used for the raw material liquid 300 include 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, chloroform, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, trichloroethane, dichloropropane, dibromoethane, dibromopropane, methyl bromide, ethyl bromide, odor Propyl chloride, acetic acid, benzene, toluene, hexane, cyclohexane, cyclohexanone, cyclopentane, o-xylene, p-xylene, m-xylene, acetonitrile, tetrahydrofuran, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfo Examples thereof include oxide, pyridine, water and the like. Moreover, the kind selected from the above may be used, and a plurality of kinds may be mixed. In addition, the above is an illustration and this invention is not limited to the said solvent.

Furthermore, an additive such as an aggregate or a plasticizer may be added to the raw material liquid 300. Examples of the additive include oxides, carbides, nitrides, borides, silicides, fluorides, sulfides, and the like. From the viewpoints of heat resistance and workability, oxides are preferably used. 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 Examples thereof include O ₃ , Yb ₂ O ₃ , HfO ₂ , Nb ₂ O _{5 and the} like. Moreover, the kind selected from the above may be used, and a plurality of kinds may be mixed. In addition, the above is an illustration and this invention is not limited to the said additive.

  The mixing ratio of the solvent and the polymer material varies depending on the solvent and the polymer material, but the amount of the solvent is preferably between about 60 wt% and 98 wt%.

  As described above, since the solvent vapor is processed without being retained by the gas flow, the raw material liquid 300 is sufficiently evaporated even if it contains 50% by weight or more of the solvent as described above, and an electrostatic stretching phenomenon occurs. It becomes possible to make it. Therefore, since the nanofiber 301 is manufactured from a state in which the solute polymer is thin, it is possible to manufacture a thinner nanofiber 301. Moreover, since the adjustable range of the raw material liquid 300 is widened, the performance range of the manufactured nanofiber 301 can be widened.

  Next, the manufacturing method of the nanofiber 301 using the nanofiber manufacturing apparatus 100 of the said structure is demonstrated.

  First, the second gas flow generation device 113 and the suction device 132 are operated to generate a gas flow in a certain direction inside the wind tunnel body 112, the guide body 102, the diffuser 127, and the concentration body 131 (gas flow). Generating step). In the above state, the nanofiber manufacturing apparatus 100 was adjusted so that the air volume in the guide body 102 was 30 m2 per minute.

  Next, the raw material liquid 300 is supplied from the supply unit 142 to the inside of the effluent body 110 by the supply device 141 (raw material liquid supply process). The raw material liquid 300 is supplied from the supply source 144 through the supply path 114 to the inside of the effluent 110 from the end of the supply unit 142. Specifically, polyurethane was selected as the material of the nanofiber 301, and N, N-dimethylacetamide was selected as the solvent (also referred to as a solvent). The mixing ratio was 25% by weight of polyurethane and 75% by weight of N, N-dimethylacetamide.

  Next, the charging electrode 121 is set to a positive or negative high voltage by the charging power source 122. Charges are particularly concentrated on the protrusion 151 of the effluent body 110 disposed at the closest distance to the charging electrode 121, and the charge is transferred to the raw material liquid 300 that flows out into the space along the flow path part 153 of the effluent body 110. Then, the raw material liquid 300 is charged (charging process).

  At the same time as the charging step, a gas flow is ejected from the ejection unit 163 by the gas flow generator 106. The raw material liquid 300 flowing out from the supply unit 142 by the gas flow flows out into the flow space through the flow path unit 153 of the outflow body 110 toward the tip (supply process, outflow process).

  Specifically, an outflow body 110 having an outer diameter at the tip of 60 mm was used. The outflow body 110 is provided with 24 flow path portions 153 at equal intervals in the circumferential direction, and the depth of the flow path portions 153 is 0.5 mm. Further, the protruding portion 151 protruded 1.5 mm from the surface of the outflow body 110. On the other hand, the charging electrode 121 having an inner diameter of Φ600 mm was used, and the charging electrode 121 was made negative 60 KV with respect to the ground potential by the charging power source 122. As a result, positive charges are induced in the projecting portion 151 of the effluent body 110, and the positively charged raw material liquid 300 flows out.

  As described above, the raw material liquid 300 flows out into the space along the protruding portion 151 without staying on the surface of the outflow body 110.

  The raw material liquid 300 that has flowed out from the front end of the outflow body 110 is transported by a gas flow (conveying step), and is guided to the guide body 102 in the gas flow.

  Here, since the charged state of the raw material liquid 300 and the charging electrode 121 are opposite in polarity, they are attracted by the Coulomb force and try to fly toward the charging electrode 121, but most of the raw material liquid toward the charging electrode 121. The direction of 300 is changed by the gas flow, and the aircraft 300 flies toward the guide body.

  The raw material liquid 300 is discharged from the discharge device 101 while manufacturing the nanofiber 301 by the electrostatic stretching phenomenon (nanofiber manufacturing process). Here, since the raw material liquid 300 flows out in a strong charged state (high charge density), electrostatic stretching easily occurs, and most of the raw material liquid 300 that flows out changes to the nanofibers 301. In addition, since the raw material liquid 300 flows out in a strong charged state (high charge density) and flows out in a thin state by the flow path portion 153, electrostatic stretching occurs over many orders, and the wire diameter is small. Nanofibers 301 are manufactured in large quantities.

  Further, the gas flow is heated by the heating device 125, and while guiding the flight of the raw material liquid 300, heat is applied to the raw material liquid 300 to promote evaporation of the solvent and promote electrostatic stretching.

  The nanofibers 301 emitted from the emission device 101 as described above are introduced into the guide body 102. Then, the nanofiber 301 is guided toward the collection device 103 while being conveyed in the gas flow inside the guide body 102 (guide process).

  The nanofibers 301 transported to the diffuser 127 are rapidly reduced in speed and are uniformly dispersed (diffusion process).

  In this state, the suction device 132 disposed behind the member 128 to be deposited sucks the gas flow together with the solvent that is the evaporated component, and attracts the nanofiber 301 onto the member 128 to be deposited (attraction process). . In addition, an electric field is generated by the attracting electrode 134 to which a voltage is applied, and the nanofiber 301 is also attracted by the electric field (attraction process).

  As described above, the nanofiber 301 is collected by being separated from the gas flow by the deposition target member 128 (collecting step). Since the member to be deposited 128 is slowly transferred by the winding device 129, the nanofiber 301 is also collected as a long belt-like member extending in the transfer direction.

  The gas flow that has passed through the deposition target 128 is accelerated by the suction device 132 and reaches the recovery device 105. The recovery device 105 separates and recovers the solvent component from the gas stream (recovery process).

  By using the nanofiber manufacturing apparatus 100 configured as described above and carrying out the above nanofiber manufacturing method, the raw material liquid 300 flows out stably into the space, and the high-quality nanofiber 301 is stabilized. Can be manufactured for a long time. Further, even when the resin adheres to the effluent body 110, the resin or the like can be easily removed from the opening of the flow path portion 153.

  Next, another embodiment of the present invention will be described.

  FIG. 7 is a perspective view schematically showing another embodiment.

  The nanofiber manufacturing apparatus 100 shown in the figure integrates the function of the charging electrode 121 and the function of the attracting electrode 134 and integrates the charging apparatus 111 and the electric field attracting apparatus 133. In this case, when a high voltage is applied between the outflow body 110 and the charging electrode 121, the raw material liquid 300 flowing out from the outflow body 110 can be charged with the polarity on the outflow body 110 side. Then, the nanofiber 301 is manufactured by the electrostatic stretching phenomenon, and the nanofiber 301 is attracted to the attracting electrode 134 (charged electrode 121) having a polarity opposite to that of the outflow body 110. The attracted nanofibers 301 are deposited and collected on the deposition target member 128 disposed between the attracting electrode 134 and the effluent 110.

  FIG. 8 is a cross-sectional view showing the outflow body from the side.

  As shown in these drawings, the effluent body 110 has a shape obtained by cutting the cylinder at a surface parallel to the axis of the cylinder and away from the axis, and the raw material liquid 300 flowing along the inner surface of the effluent body 110 is The gas flows out from the edge of the outflow body 110 arranged to intersect the gas flow injected from the injection unit 163. Thereby, the raw material liquid 300 flowing along the outflow body 110 can flow out from the outflow body 110 into the space in a thin (thin) state, and the quality of the manufactured nanofiber 301 can be improved.

  In addition, if the portion from which the raw material liquid 300 flows out has a substantially planar shape like the shape of the effluent body 110 according to the present embodiment, the raw material liquid 300 can flow out in a long linear range. It becomes possible to manufacture the nanofiber 301 in a range.

  In the present embodiment, the charging electrode 121 may be disposed in the vicinity of the outflow body 110. In addition, an attracting electrode 134 separate from the charging electrode 121 may be arranged, or the nanofiber 301 may be conveyed by a gas flow generated by the second gas flow generator 113.

  Moreover, as shown in FIG. 9, the outflow body 110 may have a rotating body shape and may be rotated by a motor 170 or the like. In this case, the uniformity in the circumferential direction of the manufactured nanofiber 301 can be ensured.

  The present invention can be used for producing nanofibers, spinning using nanofibers, and producing nonwoven fabrics.

It is a top view which cuts off and shows part of embodiment of a nanofiber manufacturing apparatus. It is a top view which notches and shows a part of discharge | release apparatus. It is a perspective view which shows the external appearance of the discharge | release apparatus. It is a perspective view which shows an outflow body. It is sectional drawing which shows an outflow body, a supply part, and an injection part. It is a perspective view which shows the guide body vicinity. It is a perspective view which shows other embodiment typically. It is sectional drawing which shows an outflow body from the side. It is sectional drawing which shows another outflow body from the side.

DESCRIPTION OF SYMBOLS 100 Nanofiber manufacturing apparatus 101 Discharge apparatus 102 Guide body 103 Collection apparatus 104 Attraction apparatus 105 Recovery apparatus 106 Gas flow generation apparatus 110 Outflow body 111 Charging apparatus 112 Wind tunnel body 113 Second gas flow generation apparatus 114 Supply path 116 Rotating shaft body 117 Drive Device 121 Charging electrode 122 Charging power source 123 Grounding device 125 Heating device 127 Diffusion body 128 Member to be deposited 129 Winding device 130 Member supply device 131 Concentrating body 132 Suction device 133 Electric field attraction device 134 Induction electrode 135 Induction power source 141 Supply device 142 Supply unit 143 Gas attracting device 144 Supply source 151 Protrusion part 152 Tip part 153 Flow path part 161 Compressor 162 Tube 163 Injection part 170 Motor 300 Raw material liquid 301 Nanofiber

Claims (9)

A nanofiber manufacturing apparatus for manufacturing nanofibers by stretching a raw material liquid in space,
An outflow body having a flow path portion that forms a flow path for guiding the raw material liquid and an opening along the flow path, up to a front end where the raw material liquid flows into the space;
A supply device for supplying a raw material liquid to the effluent;
A gas flow generator for generating a gas flow for flowing the supplied raw material liquid to the tip;
A charging device for charging the raw material liquid;
A nanofiber manufacturing apparatus comprising:   The nanofiber manufacturing apparatus according to claim 1, wherein the flow path portion is a groove provided in the outflow body. The said outflow body is a nanofiber manufacturing apparatus of Claim 1 or Claim 2 provided with the protrusion part sharpened to the front-end | tip. The tip of the effluent has a cylindrical shape,
The flow path portion is on the inner surface of the cylindrical shape,
The opening opens inward of the cylindrical shape,
The said charging device is a nanofiber manufacturing apparatus of any one of Claims 1-3 provided with the cyclic | annular charging electrode surrounding the front-end | tip of the said outflow body. further,
The nanofiber manufacturing apparatus according to claim 4, wherein the outflow body is gradually reduced in diameter toward the tip. further,
The nanofiber manufacturing apparatus according to claim 4 or 5, further comprising a driving device that rotates the effluent body around the cylindrical axis.   Furthermore, the nanofiber manufacturing apparatus of Claim 1 provided with the 2nd gas flow generation apparatus which produces | generates the gas flow which conveys the manufactured nanofiber. further,
A collection device for collecting nanofibers;
The nanofiber manufacturing apparatus according to claim 1, further comprising an attracting device that attracts nanofibers to the collecting device. A nanofiber production method for producing a nanofiber by stretching a raw material liquid in a space,
The raw material liquid is supplied from the supply device to the effluent,
Generated by a gas flow generating device in a flow path portion provided in the outflow body to a flow path section for forming a flow path for guiding the raw material liquid and an opening along the flow path to the tip where the raw material liquid flows out into the space The raw material liquid is poured by the gas flow
The raw material liquid is allowed to flow into the space from the tip,
The raw material liquid is charged by being charged,
A nanofiber manufacturing method for manufacturing a nanofiber by stretching a raw material liquid in a space.

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