JP2010180490A - Apparatus for producing nanofiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for producing a nanofiber of which the maintenance ability is improved while keeping the quality of the produced nanofiber. <P>SOLUTION: The apparatus 100 for producing the nanofiber by drawing a raw material liquid 300 in space includes a discharging body 115 which has a plurality of discharging holes 118 for discharging the raw material liquid 300 into the space and on the surface of which the opening parts of the discharging holes 118 are arranged, an electrifying device 111 for electrifying the raw material liquid 300, and protrusion parts 151 present at the peripheries of the openings of the discharging holes 118 on the surface of the discharging body 115 and protruded so as to be directed to the discharged direction of the raw material liquid 300. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a nanofiber manufacturing apparatus, and more particularly to a nanofiber manufacturing apparatus capable of improving 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, a nanofiber manufacturing apparatus according to the present invention is a nanofiber manufacturing apparatus for manufacturing a nanofiber by stretching a raw material liquid in a space, and an outflow hole for allowing the raw material liquid to flow into the space. A plurality of flow-out bodies in which the opening portion of the outflow hole is disposed on the surface, a charging device for charging the raw material liquid, and the outflow direction of the raw material liquid on the surface of the outflow body at the periphery of the opening portion And a protruding portion protruding toward the surface.

  According to this, even when the hole length of the outflow hole is shorter than the size of the opening of the outflow hole, it is possible to stabilize the outflow direction of the raw material liquid by keeping the raw material liquid along the protruding portion.

Moreover, it is preferable that the said protrusion part is provided with the pointed front-end | tip part.
As a result, the charge concentrates on the tip, and the charging efficiency for the raw material liquid can be improved.

  Note that the pointed tip portion is a concept including a tip such as a cone having a point-like tip or a tip having a corner having a tip-like shape.

Moreover, it is preferable that the protrusion includes a plurality of the tip portions.
Thereby, it is possible to improve the charging efficiency of the raw material liquid by improving the possibility that the raw material liquid is charged.

  Moreover, it is preferable that the said protrusion part is provided with the groove part opened toward the said outflow hole from the base end part by the side of the said outflow body to the front-end | tip part.

  Thereby, since the raw material liquid can flow out into the space after flowing along the groove, it is possible to stabilize the outflow state of the raw material liquid while maintaining the maintainability of the outflow body. Moreover, the fineness of the raw material liquid which flows out can be adjusted with the fineness of a groove | channel, and it becomes possible to manufacture the nanofiber of arbitrary thinness stably.

Furthermore, it is preferable that the protrusion includes a plurality of the grooves.
As a result, the raw material liquid flowing out from the outflow hole is divided into a plurality of grooves and flows out into the space along each groove, so that even if the outflow hole is relatively large, the raw material liquid flowing out into the space The wire diameter can be reduced. Therefore, since the resin is less likely to be clogged in the outflow hole, the maintenance period can be extended and the maintenance can be easily performed.

  Note that it is preferable to provide tip portions for the plurality of groove portions, respectively, because charges can be efficiently supplied to the raw material liquid divided by the plurality of groove portions.

  And a driving device for rotating the outflow body, wherein the opening portion opens in a radial direction with respect to a rotation axis of the outflow body, and the protruding portion is rearward in the rotation direction of the outflow body with respect to the opening portion. It is preferable to arrange | position.

  Thereby, a large amount of raw material liquid can be discharged into a narrow space by flowing the raw material liquid in the radial direction by centrifugal force, and the production efficiency of the nanofiber can be improved. In addition, since the raw material liquid flowing along the surface of the effluent body is blocked by the projecting portion by rotating the effluent body, the flow of the raw material liquid can be changed in the radial direction. Can flow into the space.

  Furthermore, it is preferable that the protrusion is disposed between the opening and an adjacent opening disposed behind the opening in the rotation direction of the outflow body.

  Thereby, it is possible to prevent the raw material liquid flowing out from the different opening portions from being connected to the surface of the outflow body, and the raw material liquid flowing out from the opening portion can be discharged into the space for each opening portion.

  According to the present invention, it is possible to maintain or improve the quality such as the fineness of the manufactured nanofiber while improving the maintainability of the nanofiber manufacturing apparatus.

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, and an attracting device 104.

  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 device 110, a charging device 111, a wind tunnel body 112, a gas flow generation device 113, and a supply path 114.

  The outflow device 110 is a device that causes the charged raw material liquid 300 to flow out into the space. In the present embodiment, the outflow device 110 is a device that causes the raw material liquid 300 to flow out radially by centrifugal force. The outflow device 110 includes an outflow body 115, a rotating shaft body 116, and a driving device 117.

  The outflow body 115 is a member for allowing the raw material liquid 300 to flow out into the space. As shown in FIG. 4, the outflow body 115 is a member provided with a large number of outflow holes 118 and protrusions 151.

  In the case of the present embodiment, the effluent body 115 is a container that allows the raw material liquid 300 to flow out into the space by centrifugal force due to its rotation while the raw material liquid 300 is injected inward, and one end is closed. It has a cylindrical shape, and has a large number of outflow holes 118 through which the raw material liquid 300 flows out from the inside of the outflow body 115 to the outside. The outflow body 115 is formed of a conductor in order to give a charge to the stored raw material liquid 300. The outflow body 115 is rotatably supported by a bearing 119.

  The protruding portion 151 is a portion that protrudes in the radial direction on the surface of the outflow body 115 at the periphery of the opening of the outflow hole 118. In the case of the present embodiment, the protruding portion 151 has a shape obtained by partially cutting a conical shape having a sharp tip 152 with a cylindrical shape having the same diameter as the outflow hole 118. The protrusion 151 has a pointed end 152 that is pointed and covers a part of the periphery of the opening of the outflow hole 118. The projecting portion 151 has a groove portion 153 that is a part of a conical shape that has been cut into a cylindrical shape. The groove portion 153 is provided from the base end portion to the tip end portion of the projecting portion 151, opens toward the outflow hole 118, and opens toward the rotation direction of the outflow body 115 (arrow in FIG. 4). ing. The protrusion 151 is arranged behind the outflow hole 118 in the rotation direction of the outflow body 115 (arrow in FIG. 4).

  Specifically, it is preferable that the diameter of the outflow body 115 is adopted from a range of 10 mm or more and 300 mm or less. This is because if it is too large, it will be difficult to concentrate the raw material liquid 300 and the nanofiber 301 by the gas flow described later, and if the weight balance is slightly deviated, for example, the rotational axis of the effluent 115 is deviated, a large vibration will occur. This is because a structure that firmly supports the outflow body 115 is required to suppress the vibration. On the other hand, if it is too small, the rotation for causing the raw material liquid 300 to flow out by centrifugal force must be increased, which causes problems such as load and vibration of the drive source. Furthermore, it is preferable to employ the diameter of the outflow body 115 from the range of 20 mm or more and 150 mm or less.

  In addition, the shape of the outflow hole 118 is preferably circular, and the diameter thereof is preferably from about 0.01 mm to 3 mm, although it depends on the thickness of the outflow body 115. This is because if the outflow hole 118 is too small, it is difficult to cause the raw material liquid 300 to flow out of the outflow body 115, and if it is too large, the unit of the raw material liquid 300 that flows out from one outflow hole 118. This is because the amount per hour becomes too large (that is, the thickness of the line formed by the flowing out raw material liquid 300 becomes too thick), making it difficult to manufacture the nanofiber 301 having a desired diameter. Further, it is preferable that the outflow hole 118 has a short hole length. This is because it is easy to remove the resin blocking the outflow hole 118 during maintenance. Specifically, it is preferable that the diameter of the outflow hole 118 is 50 times or less and the maximum hole length is 2 mm or less.

  Further, the protrusion 151 is not limited in the present invention. For example, as shown in FIG. 5, the protruding portion 151 may include a plurality of groove portions 153 and a plurality of sharp tip portions 152 with respect to the groove portions 153.

  With such a configuration, the raw material liquid 300 is divided into a plurality of grooves 153 and can flow out into the space along the grooves 153. Further, since charges are supplied from the protrusions 151 to the respective raw material liquids 300, the raw material liquids 300 can be efficiently charged.

  Further, the positional relationship between the protrusion 151 and the outflow hole 118 is not particularly limited. The protrusion 151 may be separated from the edge of the opening of the outflow hole 118. That is, the meaning of “the protrusion 151 is the peripheral edge of the opening of the outflow hole 118” is not limited to the case where the groove 153 of the protrusion 151 is continuously disposed in the opening of the outflow hole 118, but is disposed in the vicinity. This includes cases where In addition, when the outflow body 115 rotates in a predetermined direction (arrow R in FIG. 5) and a gas flow flows in a predetermined direction (arrow W in FIG. 5) from a gas flow generator 113 described later, the protrusion 151 is Further, it may be located behind the outflow hole 118 in the rotational direction and at the leeward position of the gas flow. As shown in FIG. 6, the position of the protrusion 151 with respect to the outflow hole 118 includes a vector A indicating the strength of the flow of the raw material liquid 300 by the rotation of the outflow body 115 and the strength of the flow of the raw material liquid 300 by the gas flow. It is preferable to arrange in the direction (vector C direction) in which the vector B shown is synthesized.

  That is, as described above, “the projecting portion 151 is arranged behind the outflow hole 118 in the rotation direction of the outflow body 115 (arrow in FIG. 4)”, the arrangement of the projecting portion 151 is vector C It also includes the case of arranging in the direction of.

  Further, as shown in FIG. 7, a plurality of outflow holes 118 may be provided with one protrusion 151.

  In addition, the outflow body 115 is not only a member that causes the raw material liquid 300 to flow out into the space by the centrifugal force of its own rotation, but is also stationary, and the pressurized raw material liquid 300 flows out from the outflow hole 118. A member may be used. Moreover, the shape of the outflow body 115 that causes the raw material liquid 300 to flow out by centrifugal force is not limited to a cylindrical shape, and may be a polygonal cylindrical shape having a polygonal cross section or a conical shape. It is sufficient that the raw material liquid 300 can flow out of the outflow hole 118 by centrifugal force by rotating the outflow hole 118. Further, the shape of the outflow hole 118 is not limited to a circular shape, and may be a polygonal shape or a star shape.

  The rotating shaft body 116 is a shaft body for transmitting a driving force for rotating the outflow body 115 and causing the raw material liquid 300 to flow out by centrifugal force, and is inserted into the outflow body 115 from the other end of the outflow body 115. This is a rod-like body in which the closed portion and one end portion of the outflow body 115 are joined. The other end is connected to the rotating shaft of the driving device 117. The rotating shaft body 116 is connected to the driving device 117 via the insulator 120, and the outflow body 115 and the driving device 117 are electrically insulated. This is to protect the drive device 117 when the connection of the effluent body 115 to the ground is broken due to an accident or the like. The rotating shaft body 116 is rotatably supported by a bearing 119.

  The driving device 117 is a device that applies a rotational driving force to the outflow body 115 via the rotating shaft body 116 in order to cause the raw material liquid 300 to flow out from the outflow hole 118 by centrifugal force. The number of revolutions of the outflow body 115 is selected from a range of several rpm or more and 10,000 rpm or less depending on the diameter of the outflow hole 118, the viscosity of the raw material liquid 300 to be used, the type of polymer substance in the raw material liquid, and the like. Preferably, when the drive device 117 and the efflux body 115 are linearly moved as in the present embodiment, the rotational speed of the drive device 117 coincides with the rotational speed of the efflux body 115.

  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 charges to the grounded outflow body 115 when the charging electrode 121 is at 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 arranged so as to surround the periphery of the outflow body 115. When a positive voltage is applied to the charging electrode 121, a negative charge is induced in the outflow body 115, and when a negative voltage is applied to the charging electrode 121, a positive charge is induced in the outflow body 115. .

  The size of the charging electrode 121 needs to be larger than the diameter of the outflow body 115, and the diameter is preferably selected from a 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 115. Further, the cross-sectional shape of the charging electrode 121 may be not only rectangular but also round.

  The grounding device 123 is a member that is electrically connected to the outflow body 115 and can maintain the outflow body 115 at the ground potential. One end of the grounding device 123 functions as a brush so that the electrical connection state can be maintained even when the outflow body 115 is in a rotating state, 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 generated 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 or more and 200 KV or less. 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 115 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 115 is the closest. Is preferred.

  If an induction method in which one electrode is grounded as the charging device 111 as in the present embodiment is adopted, charge can be imparted to the raw material liquid 300 while the effluent 115 is maintained at the ground potential. If the outflow body 115 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 115 from the outflow body 115, and the outflow apparatus 110 can be simplified. A structure can be adopted, which is preferable.

  Note that as the charging device 111, a charge may be applied to the raw material liquid 300 by connecting a power source to the effluent body 115, maintaining the effluent body 115 at a high voltage, and grounding the charging electrode 121. In addition, the outflow body 115 is formed of an insulator, and an electrode that directly contacts the raw material liquid 300 stored in the outflow body 115 is disposed inside the outflow body 115, and charges are applied to the raw material liquid 300 using the electrode. It may be a thing. In the case where an electrode is arranged directly on the effluent 115 or directly on the raw material liquid, the polarity of the charge charged in the raw material liquid is the same as the polarity of the applied voltage.

  The gas flow generation device 113 is a device that changes the flight direction of the raw material liquid 300 flowing out from the outflow body 115 and generates a gas flow for transporting the nanofiber 301 and passing the inside of the guide body 102. . In the case of the present embodiment, the gas flow generation device 113 is provided on the back portion of the drive device 117 and generates a gas flow from the drive device 117 toward the tip of the outflow body 115. The gas flow generating device 113 can generate wind power that can change the raw material liquid 300 flowing out from the outflow body 115 in the radial direction in the axial direction. In FIG. 2, the gas flow is indicated by arrows. As the gas flow generator 113, a blower provided with an axial fan can be exemplified.

  Note that the gas flow generator 113 may be constituted by another blower 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 gas flow generation device 113 that actively generates a gas flow, but the gas flow is generated inside the wind tunnel body 112 or the like by some device. It is assumed that the nanofiber manufacturing apparatus 100 includes the gas flow generation device 113.

  The wind tunnel body 112 is a conduit that guides the gas flow generated by the gas flow generation device 113 between the charging electrode 121 and the outflow body 115. In the case of the present embodiment, the gas flow guided by the wind tunnel body 112 crosses the raw material liquid 300 flowing out from the outflow hole 118 of the outflow body 115 while passing through the inside of the charging electrode 121, and Change the flight direction.

  Furthermore, the discharge device 101 includes a gas flow control device 124 and a heating device 125.

  The gas flow control device 124 has a function of controlling the gas flow so that the gas flow generated by the gas flow generation device 113 does not hit the opening end of the outflow hole 118. In the case of the present embodiment, as the gas flow control device 124, an air passage body that guides the gas flow to flow in a predetermined region is employed. Since the gas flow does not directly hit the outflow hole 118 by the gas flow control device 124, the raw material liquid 300 flowing out from the outflow hole 118 is prevented from evaporating early and blocking the outflow hole 118 as much as possible. The liquid 300 can be kept flowing out stably. The gas flow control device 124 may be a wall-shaped windbreak wall that is disposed on the windward side of the outflow hole 118 and prevents the gas flow from reaching the vicinity of the outflow hole 118.

  The heating device 125 is a heating source that heats the gas constituting the gas flow generated by the 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.

  The supply path 114 is a path for supplying the raw material liquid 300 to the inside of the outflow body 115 from an external tank for the raw material liquid 300 (not shown). In the case of the present embodiment, the supply path 114 is formed of a tubular body.

FIG. 8 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 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 member to be deposited 128 is supplied from the supply device 130 while 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 along with the nanofiber 301 to be deposited while being drawn out from the supply device 130 while winding up 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 the 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 polymer as a solute is thin, it is possible to manufacture a thinner nanofiber 301. Moreover, since the adjustable range of the raw material liquid 300 is expanded, the performance range of the manufactured nanofiber 301 can be increased.

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

  First, the gas flow generating device 113 and the suction device 132 are operated to generate a gas flow in a fixed direction inside the wind tunnel body 112, the guide body 102, the diffuser 127, and the concentrated body 131 (gas flow generation process). ). 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 to the inside of the outflow body 115 (raw material liquid supply process). The raw material liquid 300 is separately stored in a tank (not shown), passes through the supply path 114, and is supplied into the effluent 115 from the other end of the effluent 115. Specifically, PVA (polyvinyl alcohol) is selected as the material of the nanofiber 301, and the raw material liquid 300 is obtained by dissolving PVA in water at 10% by weight using a solvent (also referred to as a solvent) as water. Was used.

  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 115 arranged at the center of the charging electrode 121, and the charge flows out from the outflow hole 118 and is transferred to the raw material liquid 300 that flows out into the space along the groove 153. The raw material liquid 300 is charged (charging process).

  At the same time as the charging step, the outflow body 115 is rotated by the driving device 117, and the charged raw material liquid 300 flows out from the outflow hole 118 by centrifugal force (outflow step).

  Specifically, an effluent 115 having an outer diameter of Φ60 mm was used. 108 outflow holes 118 were provided at equal intervals in the circumferential direction, and the hole diameter was 0.5 mm. Further, the protruding portion 151 protruded from the surface of the outflow body 115 by 1.5 mm. The raw material liquid 300 was caused to flow out by rotating the outflow body 115 at 2000 rpm. 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, a positive charge is induced in the effluent 115, and the positively charged raw material liquid 300 flows out.

  As described above, the raw material liquid 300 flows out radially into the space along the protruding portion 151 without staying on the surface of the outflow body 115.

  The raw material liquid 300 that has flowed radially in the radial direction of the outflow body 115 is changed in flight direction by the gas flow 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 strongly charged state (high charge density), electrostatic stretching occurs over many orders, and a large amount of nanofibers 301 having a small wire diameter are manufactured.

  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 outflow hole 118 is clogged, the resin or the like can be easily removed from the outflow hole 118.

  Further, even when the raw material liquid 300 is caused to flow out by centrifugal force, the protruding portion 151 functions as a weir, and it is possible to avoid the raw material liquid 300 from staying on the surface of the outflow body 115.

  When the outflow holes 118 on the surface of the outflow body 115 are arranged adjacent to each other in the circumferential direction of the rotation of the outflow body 115, the raw material liquid 300 flowing out from one outflow hole 118 is adjacent to the outflow body 115. In some cases, it may be connected to the raw material liquid 300 flowing out from the outflow hole 118. In such a case, as in the embodiment of the present application, by arranging the protrusion 151 between the adjacent outflow holes 118, the protrusion 151 serves as a weir and flows out from different outflow holes 118. The raw material liquid 300 is prevented from mixing on the surface of the outflow body 115, and the raw material liquid 300 flowing out from the outflow hole 118 travels through the protrusion 151 and flows out from the tip 152 of the protrusion 151 into the space. The nanofiber is manufactured from the raw material liquid 300 that flows out stably.

  Similarly, when the number of rotations of the outflow body 115 is small, the raw material liquid 300 flowing out from the outflow hole 118 may not be connected to the raw material liquid 300 flowing out from the adjacent outflow hole 118. However, since the raw material liquid 300 flowing out from the different outflow holes 118 is connected by increasing the rotational speed of the outflow body 115, the projecting portion 151 is provided between the different outflow holes 118. The form becomes useful.

  The present invention can be used for the manufacture of nanofibers, the manufacture of nonwoven fabrics made of nanofibers, and the manufacture of yarns made of nanofibers.

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 the protrusion part vicinity. It is a perspective view which shows another aspect of a protrusion part. It is a top view which shows the positional relationship of a protrusion part and an outflow hole. It is a perspective view which shows another aspect of a protrusion part. It is a perspective view which shows typically the external appearance of a guide body vicinity. It is sectional drawing which shows typically the outflow state of a raw material liquid.

DESCRIPTION OF SYMBOLS 100 Nanofiber manufacturing apparatus 101 Ejection apparatus 102 Guide body 103 Collection apparatus 104 Attraction apparatus 105 Recovery apparatus 110 Outflow apparatus 111 Charging apparatus 112 Wind tunnel body 113 Gas flow generation apparatus 114 Supply path 115 Outflow body 116 Rotating shaft body 117 Drive apparatus 118 Outflow hole 119 Bearing 120 Insulator 121 Charging electrode 122 Charging power supply 123 Grounding device 124 Gas flow control device 125 Heating device 127 Diffuser 128 Deposited member 129 Winding device 130 Feeding device 131 Concentrating body 132 Suction device 133 Electric field attraction device 134 Inducing electrode 135 Attraction power source 143 Gas attraction device 151 Protruding portion 152 Tip portion 153 Groove portion 300 Raw material liquid 301 Nanofiber

Claims (10)

A nanofiber manufacturing apparatus for manufacturing nanofibers by stretching a raw material liquid in space,
A plurality of outflow holes through which the raw material liquid flows out into the space, and an outflow body in which an opening of the outflow hole is disposed on the surface;
A charging device for charging the raw material liquid;
An apparatus for producing nanofibers, comprising: a projecting portion projecting toward the outflow direction of the raw material liquid on the surface of the outflow body at the periphery of the opening. 2. The nanofiber manufacturing apparatus according to claim 1, wherein a hole length of the outflow hole is 50 times or less of a diameter of the opening and a maximum hole length is 2 mm or less. The nanofiber manufacturing apparatus according to claim 1, wherein the protrusion includes a pointed tip. The nanofiber manufacturing apparatus according to claim 3, wherein the protruding portion includes a plurality of the tip portions. 2. The nanofiber manufacturing apparatus according to claim 1, wherein the protruding portion includes a groove portion that opens from a base end portion on the outflow body side to a distal end portion toward the outflow hole. The nanofiber manufacturing apparatus according to claim 5, wherein the protruding portion includes a plurality of the groove portions. further,
A drive device for rotating the effluent body;
The opening is opened in a radial direction with respect to the rotation axis of the outflow body,
2. The nanofiber manufacturing apparatus according to claim 1, wherein the protrusion is disposed behind the opening in the rotation direction of the outflow body.   2. The nanofiber manufacturing apparatus according to claim 1, wherein the protrusion is disposed between the opening and an adjacent opening disposed at a rear side in the rotation direction of the outflow body with respect to the opening. . further,
Comprising a gas flow generator for generating a gas flow for changing the flight direction of the raw material liquid flowing out of the effluent,
The nanofiber manufacturing apparatus according to claim 1, wherein the protruding portion is disposed leeward of the gas flow with respect to the opening. 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.

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