JP2012036522A - Apparatus and method for producing nanofiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the quality of nanofibers by efficiently discharging solvent vapor.SOLUTION: A nanofiber production apparatus 100 for producing nanofibers 301 by electrically drawing a raw material liquid 300 in a space includes: an outflow member 101 in which openings 119 of a plurality of outflow holes 118 for allowing the raw material liquid 300 to flow out into the space in one direction are arranged in an arrangement range which is a virtual two-dimensional range in a long narrow belt-like shape; charging means 102 for charging the raw material liquid 300 flowing out of the outflow member 101; and blowing means 103 for generating a curtain-like gas flow A flowing along the raw material liquid 300 in the same direction as the outflow direction, in which the raw material liquid 300 flows out of the outflow member 101, and extending almost uniformly all over the arrangement range in the longitudinal direction.

Description

  The present invention relates to a nanofiber manufacturing apparatus and a nanofiber manufacturing method for manufacturing a fiber (nanofiber) having a fineness of submicron order or nano order by electrostatic stretching phenomenon.

  As a method for producing a filamentous (fibrous) material made of a resin and having a submicron scale or nanoscale diameter, a method using an electrostatic stretching phenomenon (electrospinning) is known.

  This electrostatic stretching phenomenon means that a raw material liquid in which a solute such as a resin is dispersed or dissolved in a solvent is discharged (injected) into the space by a nozzle or the like, and an electric charge is applied to the raw material liquid to charge the space. This is a method of obtaining nanofibers by electrically stretching a raw material liquid in flight.

  The electrostatic stretching phenomenon will be described more specifically as follows. That is, the raw material liquid that has been 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 when the repulsive Coulomb force generated in the raw material liquid exceeds the surface tension of the raw material liquid, the raw material liquid explodes. The phenomenon that the film is stretched linearly occurs. This is the electrostatic stretching phenomenon. This electrostatic stretching phenomenon occurs geometrically in succession in the space, so that nanofibers made of a resin having a diameter of sub-micron order to nano order are manufactured.

  When producing nanofibers using the electrostatic stretching phenomenon as described above, the concentration of the evaporated solvent becomes a problem. That is, if the concentration of the solvent in the space in which the raw material liquid flies is high, the solvent is difficult to evaporate from the raw material liquid, and the quality of the manufactured nanofibers is affected.

  Therefore, for example, the apparatus described in Patent Document 1 includes a deposition target member that deposits and collects nanofibers. By sucking gas from the back side of the deposition target member on which nanofibers are not deposited, In this device, the fiber is attracted to the member to be deposited and the evaporated solvent is sucked and exhausted.

JP 2008-223179 A

  However, in the apparatus of Patent Document 1, since the gas is sucked from the back side of the member to be deposited on which the nanofibers are deposited, it is difficult to efficiently suck the solvent vapor in the space where the raw material liquid flies.

  Also, when trying to suck solvent vapor that spreads over a wide area, it is necessary to suck air strongly, but in this case, turbulent flow such as swirling gas flow occurs, which adversely affects the production of nanofibers and is produced The quality of the nanofibers may be degraded.

  The present invention has been made in view of the above problems, and efficiently discharges the solvent vapor from the flight path of the raw material liquid and can maintain the quality of the manufactured nanofiber in a high state, And it aims at provision of the nanofiber manufacturing method.

  In order to achieve the above object, a nanofiber manufacturing apparatus according to the present invention is a nanofiber manufacturing apparatus that manufactures nanofibers by electrically stretching a raw material liquid in a space. An outflow body that has a plurality of outflow holes that flow out in one direction, and in which the opening of the outflow hole is arranged in an array range that is an elongated strip-like virtual two-dimensional range, and a raw material liquid that flows out of the outflow body And a curtain-like gas that flows along the raw material liquid in the same direction as the outflow direction, which is the direction in which the raw material liquid flows out from the outflow body, and spreads substantially uniformly over the entire longitudinal direction of the arrangement range. And a blowing means for generating a flow.

  According to this, since the curtain-like gas flow substantially uniformly flows along the flow of the raw material liquid that flows in the longitudinal direction of the arrangement range and affects the raw material liquid and nanofibers flying in the space. Therefore, it is possible to discharge the solvent vapor from the flying space where the raw material liquid and the nanofiber fly.

  Furthermore, an air intake unit that intakes the curtain-like gas flow generated by the air blowing unit substantially uniformly over the entire longitudinal direction of the arrangement range may be provided.

  According to this, since the substantially uniform curtain-like gas flow is sucked substantially uniformly, it is possible to suppress as much as possible the occurrence of turbulent flow in the space in which the raw material liquid and nanofibers fly. Accordingly, it is possible to efficiently discharge the solvent vapor from the flight space while maintaining the quality of the manufactured nanofiber in a high state.

  Furthermore, the deposition member that collects the nanofibers manufactured in the space in a deposition state that extends over the entire longitudinal direction of the array range, and the effluent body and the deposition member are relative to each other in a direction intersecting the longitudinal direction. And a transfer means for transferring it.

  According to this, it becomes possible to manufacture the nonwoven fabric which consists of nanofiber which makes the whole longitudinal direction of an arrangement | sequence range width. In addition, since the solvent vapor is discharged by a substantially uniform curtain-like gas flow, it is possible to manufacture a non-woven fabric formed of high-quality and non-uniform nanofibers.

  In order to achieve the above object, a nanofiber manufacturing method according to the present invention is a nanofiber manufacturing method in which a raw material liquid is electrically stretched in a space to manufacture a nanofiber, wherein a plurality of outflow holes are opened. An outflow step of flowing the raw material liquid in one direction into the space from the effluent arranged in an array range that is a virtual two-dimensional range having a long and narrow belt-like shape, and the raw material liquid flowing out of the effluent by the charging means A charging process for charging, and a curtain-like gas flow that flows along the raw material liquid in the same direction as the outflow direction, which is the direction in which the raw material liquid flows out from the effluent, and spreads substantially uniformly over the entire longitudinal direction of the arrangement range And a blowing process for generating the air by a blowing means.

  According to this, since the curtain-like gas flow substantially uniformly flows along the flow of the raw material liquid that flows in the longitudinal direction of the arrangement range and affects the raw material liquid and nanofibers flying in the space. Therefore, it is possible to discharge the solvent vapor from the flying space where the raw material liquid and the nanofiber fly.

  According to the present invention, it is possible to improve the quality of manufactured nanofibers.

FIG. 1 is a perspective view showing a nanofiber manufacturing apparatus. FIG. 2 is a perspective view showing a cutout of the outflow body. FIG. 3 is a perspective view showing a state in which the raw material liquid is flowing out from the outflow body from the front end side of the outflow body. FIG. 4 is a side view showing the nanofiber manufacturing apparatus along with the gas flow from the Y-axis direction. FIG. 5 is a perspective view showing another example of the air blowing means. FIG. 6 is a perspective view showing another example of the air blowing means. FIG. 7 is a perspective view showing another example of the blowing means. FIG. 8 is a perspective view showing another example of the air blowing means. FIG. 9 is a perspective view showing another example of the air blowing means. FIG. 10 is a perspective view showing another example of the air blowing means. FIG. 11 is a perspective view showing another example of the intake means. FIG. 12 is a perspective view showing another example of the intake means. FIG. 13 is a perspective view showing another example of the intake means. FIG. 14 is a perspective view showing another example of the intake means. FIG. 15 is a perspective view showing another example of the intake means. FIG. 16 is a perspective view showing another example of the intake means. FIG. 17 is a side view showing another example of the nanofiber manufacturing apparatus along with the gas flow from the Y-axis direction. FIG. 18 is a side view showing the nanofiber manufacturing apparatus along with the gas flow from the Y-axis direction. FIG. 19 is a perspective view showing another embodiment of the nanofiber manufacturing apparatus.

  Next, a nanofiber manufacturing apparatus and a nanofiber manufacturing method according to the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a nanofiber manufacturing apparatus.
As shown in the figure, the nanofiber production apparatus 100 is an apparatus for producing a nanofiber 301 by electrically stretching a raw material liquid 300 in a space, and includes an effluent body 101, a charging means 102, and a blower. Means 103. Further, the nanofiber manufacturing apparatus 100 includes an intake means 104, a collection means 105, and a supply means 106.

FIG. 2 is a perspective view showing a cutout of the outflow body.
The outflow body 101 includes a plurality of outflow holes 118 through which the raw material liquid 300 flows out in one direction into the space, and the opening 119 present at the tip of the outflow hole 118 is an elongated strip-like virtual two-dimensional range. It is a member arranged inside, and the raw material liquid 300 is caused to flow out into the space by the pressure of the raw material liquid 300 (which may include gravity).

  Here, as described above, the term “arrangement range” means a band-like virtual two-dimensional range in which the opening 119 at the tip of the outflow hole 118 can be arranged, and the present specification and claims. The same meaning is used throughout the range. For example, in FIG. 2, the arrangement range is a range corresponding to the tip portion 116 (described later). As described above, the arrangement range is a band-like virtual two-dimensional range. However, as shown in FIG. 2, the arrangement range may coincide with a region (tip portion 116) indicated by a physical shape. However, in the present invention, it is not necessary for the virtual arrangement range and the physical region to coincide.

  In addition, the outflow body 101 also functions as an electrode for supplying electric charge to the raw material liquid 300 that flows out, and at least a part of the portion in contact with the raw material liquid 300 is formed of a conductive member. In the case of the present embodiment, the entire outflow body 101 is made of metal, and further includes a front end portion 116, a side surface portion 117, and a storage tank 113.

  The outflow hole 118 is a hole through which the raw material liquid 300 flows out into the space in one direction (downward in the Z-axis direction in FIG. 1), and is within a narrow strip-shaped array range that occupies a part of the outflow body 101. A plurality are provided. In the case of the present embodiment, the outflow holes 118 are arranged in a straight line in the Y-axis direction so as to be parallel to each other, and the openings 119 at the tips of the outflow holes 118 are arranged in a line at a predetermined interval. They are arranged side by side.

  The hole length and hole diameter of the outflow hole 118 are not particularly limited, and a shape suitable for the viscosity of the raw material liquid 300 may be selected. Specifically, the hole length is preferably selected from a range of 1 mm or more and 5 mm or less. The hole diameter is preferably selected from a range of 0.1 mm or more and 2 mm or less. Further, the shape of the outflow hole 118 is not limited to a cylindrical shape, and an arbitrary shape can be selected. In particular, the shape of the opening 119 is not limited to a circular shape, and may be a polygonal shape such as a triangle or a quadrangle, or a shape having a protruding portion such as a star shape.

  Further, the intervals at which the openings 119 are arranged may be equally spaced, and the interval between the openings 119 at the end of the effluent 101 is wider than the interval between the openings 119 at the center of the effluent 101. Alternatively, it can be arbitrarily determined such as narrowing. In the knowledge currently obtained, when the hole diameter of the opening part 119 is 0.3 mm, as for the pitch of the opening part 119, 2.5 mm or more is preferable. This is because, when the length is less than 2.5 mm, the possibility that the raw material liquids that flow out adjacently merge with each other increases. It should be noted that these hole diameters and pitches may vary depending on other conditions such as the viscosity of the raw material liquid 300.

  Further, the openings 119 are not only arranged on the same straight line, but may be arranged in any manner as long as they are within a narrow strip-shaped arrangement range. For example, the opening part 119 may be arrange | positioned zigzag, and may be arrange | positioned so that waves, such as a sine curve, may be drawn.

  The front end portion 116 is a portion of the outflow body 101 where the opening 119 of the outflow hole 118 is disposed, and is a portion that connects the openings 119 disposed at a predetermined interval with a smooth surface. In the case of the present embodiment, the distal end portion 116 has an elongated rectangular plane on the surface, and the width thereof is set to be wider than the diameter of the corresponding opening 119.

  In addition, when the shape of the front-end | tip part 116 is not a strip | belt shape like FIG. 2, for example, even if the shape of the front-end | tip part 116 is a curved surface shape, or a sharp shape, a needle-like nozzle was located in a line. Even when there is no such tip portion 116, the “arrangement range” can be virtually set as a band-like region in which the openings 119 can be arranged.

  FIG. 3 is a perspective view showing a state in which the raw material liquid is flowing out from the outflow body from the front end side of the outflow body.

  As shown in the figure, the liquid pool 303 (around the opening 119 is formed by the presence of the tip 116 having a smooth surface (a flat surface in the case of the present embodiment) over the entire periphery of the opening 119. A so-called tailor cone is generated. The liquid pool 303 is considered to be generated due to the viscosity of the raw material liquid 300 and has a conical shape with a circular bottom surface larger than the opening 119. The liquid reservoir 303 adheres to the tip end portion 116 of the outflow body 101 so as to cover the opening 119. Then, the raw material liquid 300 flows out from the conical liquid pool 303 into the space. Thereby, since the opening part 119 does not contact air directly, it becomes possible to suppress the ionic wind generated from the opening part 119.

  As described above, since the tip end portion 116 connects a plurality of openings 119 with a smooth surface, it is possible to suppress electric field interference that occurs when a plurality of nozzles are arranged. In addition, ion wind generated in a region between the opening 119 and the opening 119 can be suppressed. Therefore, even if the openings 119 are arranged in a narrowed state, the nanofibers 301 can be manufactured satisfactorily, and therefore the production amount of the nanofibers 301 per unit time and unit area can be improved. Become.

  In addition, since the liquid reservoir 303 can be held in a good state by the distal end portion 116, it is considered that the generation of ion wind can be suppressed and the quality of the nanofiber 301 can be improved and the production efficiency can be improved.

  As shown in FIG. 2, the side surface portion 117 is two surfaces arranged so as to sandwich the outflow hole 118, and is a portion of the outflow body 101 that extends from the distal end portion 116 and is arranged in an upright state. The side surface portion 117 is provided in a state extending in the longitudinal direction (Y-axis direction) of the arrangement range, and is provided so as to sandwich all the outflow holes 118 between the two side surface portions 117. Further, as shown in FIG. 2, the side surface portions 117 are arranged such that the distance between the side surface portions 117 increases as the distance from the front end portion 116 increases.

  The outflow body 101 includes the side surface portion 117 to suppress the generation of ionic wind, and even when the ionic wind is generated, the ionic wind can be blown in a direction that does not intersect the raw material liquid 300 flowing into the space. Therefore, the nanofiber 301 can be manufactured in a stable state without being affected by the ion wind.

  Further, since the side surface portion 117 is arranged so as to become gradually narrower toward the front end portion 116, charges can be easily concentrated on the front end portion 116, and the charge can be efficiently supplied to the raw material liquid 300.

  Furthermore, since the space around the opening 119 can be widely opened, it is considered that the solvent vapor can be efficiently discharged by the gas flow generated by the air blowing means 103 to the side of the side surface portion 117.

  As shown in FIG. 2, the storage tank 113 is a tank that is formed inside the outflow body 101 and stores the raw material liquid 300 supplied from the supply means 106 (see FIG. 1). The storage tank 113 is connected to the plurality of outflow holes 118 and supplies the raw material liquid 300 to the outflow holes 118 at the same time. In the case of the present embodiment, one storage tank 113 is provided in the outflow body 101, is widely provided from one end portion to the other end portion of the outflow body 101, and is connected to all outflow holes 118.

  As described above, the storage tank 113 has a function of temporarily storing the raw material liquid 300 in the vicinity of the outflow holes 118 and supplying the raw material liquid 300 to the plurality of outflow holes 118 with an equal pressure. The raw material liquid 300 can be allowed to flow out from each outflow hole 118 in an even state. Therefore, it is possible to suppress spatial unevenness in the quality of the manufactured nanofiber 301.

  In the present embodiment, the effluent body 101 has been described as including the thin and long tip portion 116 and the side surface portion 117 arranged so as to gradually spread from the tip portion. It is not limited. For example, if the openings 119 of the outflow holes 118 are arranged in an arrangement range that is a long and narrow strip-like virtual two-dimensional range, the outflow holes 118 are provided on the peripheral wall of a circular pipe, Other forms can be exemplified by arranging the outflow holes 118 in a matrix on the bottom surface of the box-shaped outflow body 101 and arranging a plurality of needle-like nozzles in which one outflow hole 118 is provided along the axial direction.

  As shown in FIG. 1, the supply means 106 is a device that supplies the raw material liquid 300 to the effluent body 101, a tank that stores a large amount of the raw material liquid 300, a pump that pumps the raw material liquid 300 from the tank, A pipe for guiding the raw material liquid 300 to be processed is provided.

  The charging unit 102 is a device that charges the raw material liquid 300 flowing out from the effluent body 101 by applying an electric charge. In the case of the present embodiment, the charging unit 102 includes a charging electrode 121 and a charging power source 122. The outflow body 101 also functions as an element constituting the charging means 102.

  The charging electrode 121 is disposed at a predetermined distance from the effluent body 101 and has a conductivity for inducing electric charge to the effluent body 101 when the charging electrode 121 is at a higher voltage or lower voltage than the effluent body 101. It is. In the case of the present embodiment, the charging electrode 121 also functions as an attracting unit 107 that attracts the nanofiber 301 to the collecting unit 105. The charging electrode 121 is disposed at a position facing the front end portion 116 of the outflow body 101, and is grounded via a charging power source 122. On the other hand, the outflow body 101 is grounded. Therefore, when a positive voltage is applied to the charging electrode 121, a negative charge is induced in the outflow body 101, and the raw material liquid 300 is negatively charged. On the other hand, when a negative voltage is applied to the charging electrode 121, a positive charge is induced in the outflow body 101, and the raw material liquid 300 is positively charged.

  The charging power source 122 is a power source that can apply a high voltage between the effluent body 101 and the charging electrode 121 to charge the raw material liquid 300 to a desired charge density. In general, the charging power source 122 is preferably a DC power source, but does not hinder the use of the AC power source.

  The charging power source 122 may be connected to the outflow body 101 so that the outflow body 101 has a high voltage or a low voltage with respect to the charging electrode 121. Further, the charging electrode 121 and the outflow body 101 may be connected so as not to be grounded, and both electrodes of the charging power source 122 may be connected to the charging electrode 121 and the outflow body 101, respectively.

  The collecting means 105 is a device that collects the nanofibers 301 manufactured by the electrostatic stretching phenomenon. The collecting unit 105 includes a member 151 to be deposited and a transport unit 152 that can transport the member 151 to be deposited.

  The member 151 to be deposited is a member that collects the nanofibers 301 that are spread in the entire longitudinal direction of the arrangement range and are manufactured in the space. In the case of the present embodiment, the deposition target 151 is a thin strip-like long member having a width in the longitudinal direction of the arrangement range, and is supplied in a state of being wound around a roll 153. Further, the member 151 to be deposited is subjected to a surface treatment so as to be easily separated from the nanofibers 301 deposited on the surface.

  The transfer means 152 is a device that relatively transfers the outflow body 101 and the deposition target member 151 in the direction (X-axis direction) intersecting the longitudinal direction (Y-axis direction) of the arrangement range. In the case of the present embodiment, the outflow body 101 is fixed, and only the deposition target member 151 is transferred to the outflow body 101. The transfer means 152 is configured to pull out the long deposition member 151 from the roll 153 while winding it, and to transport and deposit the deposition member 151 together with the nanofiber 301 to be deposited.

  The transfer means 152 may not only move the member 151 to be deposited but also move the effluent 101 with respect to the collecting means 105. Further, the transfer means 152 may be one that transfers the member 151 to be deposited in a certain direction, and reciprocates the outflow body 101 in a direction that intersects the transfer direction of the member 151 to be deposited. In addition, the collecting means 105 is moved in a direction orthogonal to the direction in which the openings 119 are arranged, but the present invention is not limited to this, and the deposition member 151 is moved in the direction in which the openings 119 are arranged to open the outflow body 101. You may make it reciprocate in the direction orthogonal to the arrangement direction of the part 119.

  The blower means 103 flows along the raw material liquid 300 in the same direction as the outflow direction (Z-axis direction), which is the direction in which the raw material liquid 300 flows out from the outflow body 101, and the longitudinal direction (Y (Axial direction) is a device that generates a curtain-like gas flow that spreads substantially uniformly throughout.

  Here, the term “substantially uniform” described in the specification and claims of the present application is used in a sense including complete uniformity. Further, the term “abbreviated” is used in a sense including an error (tolerance) and a spread that do not depart from the present invention.

  In the case of the present embodiment, the air blowing means 103 is a device that generates a so-called air curtain, and is a slit that extends in the Y-axis direction a gas flow generated by rotating a long sirocco fan that extends in the Y-axis direction by a motor. A curtain-like gas flow is generated downward in the Z-axis direction by discharging from the air blower 131.

  According to this, the gas flow can be forced to flow almost uniformly in the vicinity of the raw material liquid 300 along the flow of the raw material liquid 300, and the flight space without adversely affecting the flying of the raw material liquid 300 and the nanofibers 301. It is possible to effectively discharge the solvent vapor.

  Further, the air outlet 131 of the air blowing means 103 is located upstream of the opening 119 of the outflow hole in the outflow direction. This is preferable because the solvent vapor immediately after the raw material liquid 300 flows out from the effluent 101 can be discharged.

  The gas flow flowing along the outflow direction of the raw material liquid 300 does not significantly affect the liquid pool 303 (tailor cone) of the raw material liquid 300 that appears in a drooping manner at the tip 116 of the outflow body 101, and is near the liquid pool 303. Since the solvent vapor is discharged, the quality of the manufactured nanofiber 301 can be maintained in a high state.

  In addition, the ventilation means 103 is not necessarily limited to a thing provided with a sirocco fan. For example, as shown in FIG. 5, a plurality of axial fans may be arranged in the longitudinal direction (Y-axis direction) of the arrangement range. In this case, the air blowing means 103 includes a driving means for driving the axial fan, and by controlling the air blowing capacity of the combination of the axial fan and the driving means by adjusting the driving means, It may create a substantially uniform gas flow in the longitudinal direction.

  Further, as shown in FIG. 6, the air B whose pressure has been increased by a compressor or the like is temporarily stored in a buffer 132 provided in the vicinity of the air blowing port 131, and then a curtain-like gas flow A is discharged from the air blowing port 131. But it doesn't matter. Further, the shape of the air blowing port 131 is not limited to a simple slit shape, and the shape may be changed depending on the type and arrangement of the gas flow generation source. For example, as shown in FIG. 7, when the gas flow source 133 is disposed in the vicinity of the central portion of the blower port 131, holes that are opened independently as the blower port 131 are provided side by side and disposed in the central portion. The opening area of the hole arranged at the end may be larger than the opening area of the hole. Further, as shown in FIG. 8, the width of the slit-shaped air blowing port 131 may be longer at the end than at the center, and the opening area may be different between the center and the end.

  Conversely, as shown in FIG. 9, when the gas flow source 133 is connected in the vicinity of both ends of the air blowing port 131, holes that are opened independently as the air blowing port 131 are arranged side by side and arranged in the center portion. It is good also as a thing with an opening area of the hole arrange | positioned at an edge part smaller than the opening area of the hole made. Further, as shown in FIG. 10, the width of the slit-shaped air outlet 131 may be made shorter at the end than at the center, and the opening area may be different between the center and the end.

  As described above, in the portion where the distance from the gas flow generation source 133 is small and the pressure of the gas flow is high, the opening area of the air blowing port 131 is reduced and the distance from the gas flow generation source 133 is increased. By gradually increasing the opening area as the pressure decreases, a substantially uniform gas flow can be discharged.

  The intake means 104 is a device that substantially uniformly sucks the curtain-like gas flow generated by the blower means 103 over the entire longitudinal direction of the arrangement range of the outflow holes 118.

FIG. 4 is a side view showing the nanofiber manufacturing apparatus along with the gas flow from the Y-axis direction.
As shown in the figure, the air intake means 104 is substantially uniform in a state where the air flow A generated by the air blowing means 103 spreads in the Y-axis direction and spreads in the Y-axis direction. Inhale. In the case of the present embodiment, the air intake means 104 is disposed on the opposite side of the air supply port 131 of the air supply means 103 with respect to the raw material liquid 300 and the nanofibers 301 flying in the space. The intake means 104 sucks a gas flow A from a slit-like intake port 141 extending in the Y-axis direction by rotating a long sirocco fan extending in the Y-axis direction by a motor (opposite to the blower means 103). is there.

  As described above, since the suction unit 104 sucks the substantially uniform curtain-like gas flow A in the longitudinal direction of the arrangement range, turbulent flow is generated in the space in which the raw material liquid 300 and the nanofibers 301 fly. Can be suppressed as much as possible. Accordingly, it is possible to efficiently discharge the solvent vapor from the flight space while maintaining the quality of the manufactured nanofiber 301 in a high state.

  In the case of the present embodiment, the direction of the gas flow A is changed by the intake means 104 to intersect the raw material liquid 300 and the nanofiber 301, thereby bending and extending the flight path of the raw material liquid 300 and the nanofiber 301. ing. Therefore, it is possible to increase the evaporation time of the solvent, and it is possible to manufacture high quality nanofibers.

  In addition, since the gas flow A, the raw material liquid 300 and the nanofibers 301 are crossed at the deposition member 151 side, that is, at a position farther from the liquid reservoir 303 than the intermediate position between the outflow body 101 and the deposition member 151, Since the flight path is changed without affecting the liquid reservoir 303, the quality of the nanofiber 301 can be maintained in a high state.

  Note that the intake means 104 is not limited to the one provided with a sirocco fan. For example, as shown in FIG. 11, a plurality of axial fans may be arranged in the longitudinal direction (Y-axis direction) of the arrangement range. In this case, the intake unit 104 includes a drive unit that drives the axial fan, and by controlling the intake capacity of the combination of the axial fan and the drive unit by adjusting the drive unit, The gas flow A may be sucked substantially uniformly in the longitudinal direction.

  In addition, as shown in FIG. 12, a vacuum tank 142 that can be made lower than the atmospheric pressure by an intake source 143 that can be evacuated or the like is provided, and a curtain-like gas flow A is sucked from the intake port 141. It doesn't matter. Further, the shape of the intake port 141 is not limited to a simple slit shape, and the shape may be changed depending on the type and arrangement of the intake source 143. For example, as shown in FIG. 13, when the gas flow intake source 143 is arranged in the vicinity of the central portion of the intake port 141, holes that open independently as the intake port 141 are provided side by side and arranged in the central portion. The opening area of the hole arranged at the end may be larger than the opening area of the hole. Moreover, as shown in FIG. 14, the width of the slit-shaped intake port 141 may be made longer at the end than at the center, and the opening area may be different between the center and the end.

  Conversely, as shown in FIG. 15, when the gas flow intake source 143 is connected in the vicinity of both ends of the intake port 141, holes that open independently as the intake port 141 are provided side by side and arranged at the center. It is good also as a thing with an opening area of the hole arrange | positioned at an edge part smaller than the opening area of the hole made. Further, as shown in FIG. 16, the width of the slit-shaped intake port 141 may be made shorter at the end than at the center, and the opening area may be different between the center and the end.

  As described above, the opening area of the intake port 141 is reduced in the portion where the distance from the intake source 143 is small and the pressure is low, and the opening area is gradually increased as the pressure increases due to the increase in the distance from the intake source 143. By increasing the size, it becomes possible to suck the gas flow substantially uniformly.

  In addition, this invention is not limited to the said embodiment. For example, another embodiment realized by arbitrarily combining the components described in this specification and excluding some of the components may be used as an embodiment of the present invention. In addition, the present invention also includes modifications obtained by making various modifications conceivable by those skilled in the art without departing from the gist of the present invention, that is, the meanings indicated in the claims. included.

  For example, in FIG. 1, the intake means 104 may not be provided. In addition, as shown in FIG. 17, the air outlet 131 of the air blowing means 103 may be disposed between the outflow holes 118, and a plurality of air intake means 104 may be provided to suck the curtain-like gas flow A from two directions. In the figure, a plurality of outflow bodies 101 having outflow holes 118 are provided, and the air outlets 131 are arranged between the outflow bodies 101. Further, the air suction means 104 may not be provided, and a gas flow may be simply generated in the direction of the member 151 to be deposited. In addition, as described in the explanation of the effluent 101, the nanofiber manufacturing apparatus 100 in which one or both of the effluents 101 are replaced with the effluent 101 in which needle-shaped nozzles are arranged in the same figure is also the present invention. include.

  According to this, even when a large number of outflow holes 118 are provided in a narrow space, the solvent vapor can be efficiently discharged by the gas flow A flowing between the outflow holes 118. Therefore, it is possible to produce high-quality nanofibers 301 with high production efficiency.

  In addition, as shown in FIG. 18, a plurality of air blowing means 103 may be arranged on both sides of the outflow body 101, and the raw material liquid 300 and nanofibers 301 flying in a plurality of curtain-like gas flows A may be sandwiched. Further, a plurality of gas flows A may be sucked by a plurality of intake means 104. Further, the gas flow A may be sucked in a state of penetrating the deposition target member 151 or the deposited nanofiber 301.

  Further, as shown in FIG. 19, guide means 145 for guiding the gas flow A taken in by the intake means 104 to the blower means 103 may be provided. The guide means 145 shown in the figure is a duct that connects the exhaust port of the intake means 104 and the intake port of the blower means 103. Thus, by circulating the gas flow A using the guide means 145, it is possible to reduce the load on the motor of the air blowing means 103 and the like. Furthermore, the intake means 104 is not provided with a motor or a fan, but is provided only with the intake port 141 and uses the intake force of the blower means 103 to intake the gas flow A that intersects the flight path of the raw material liquid 300 and the nanofiber 301. It doesn't matter what you do.

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

  Here, the resin constituting the nanofiber, which is dissolved or dispersed in the raw material liquid, includes 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 Polyhydroxy butyrate, polyvinyl acetate, polypeptides and the like, and polymeric materials such as copolymers thereof can be exemplified. 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 resin.

  Examples of the solvent used in the raw material liquid include volatile organic solvents. Specific examples are methanol, ethanol, 1-propanol, 2-propanol, hexafluoroisopropanol, tetraethylene glycol, triethylene glycol, dibenzyl alcohol, 1,3-dioxolane, 1,4-dioxane, methyl ethyl ketone, methyl isobutyl. Ketone, methyl-n-hexyl ketone, methyl-n-propyl ketone, diisopropyl ketone, diisobutyl ketone, acetone, hexafluoroacetone, phenol, formic acid, methyl formate, ethyl formate, propyl formate, methyl benzoate, ethyl benzoate, benzoate Propyl acid, methyl acetate, ethyl acetate, propyl acetate, dimethyl phthalate, diethyl phthalate, dipropyl phthalate, methyl chloride, ethyl chloride, methylene chloride, chloroform, o-chloroto Ene, p-chlorotoluene, chloroform, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, trichloroethane, dichloropropane, dibromoethane, dibromopropane, methyl bromide, ethyl bromide, propyl bromide, acetic acid, Benzene, toluene, hexane, cyclohexane, cyclohexanone, cyclopentane, o-xylene, p-xylene, m-xylene, acetonitrile, tetrahydrofuran, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, pyridine, water Etc. can be listed. 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 the raw material liquid used for this invention is not limited to employ | adopting the said solvent.

Further, an inorganic solid material may be added to the raw material liquid. Examples of the inorganic solid material include oxides, carbides, nitrides, borides, silicides, fluorides, sulfides, etc., but oxidation is performed from the viewpoint of heat resistance and workability of the manufactured nanofibers. It is preferable to use a product. 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 the substance added to the raw material liquid of this invention is not limited to the said additive.

  The mixing ratio of the solvent and the solute in the raw material liquid varies depending on the type of solvent selected and the type of solute, but the amount of solvent is preferably between about 60 wt% and 98 wt%. The solute is preferably 5 to 30% by weight.

  First, the raw material liquid 300 is supplied to the effluent body 101 by the supply means 106 (supply process). As described above, the raw material liquid 300 is filled in the storage tank 113 of the effluent body 101.

  Next, the charging electrode 121 is set to a positive or negative high voltage by the charging power source 122. Charge concentrates on the tip 116 of the effusing body 101 facing the charging electrode 121, and the charge passes through the outflow hole 118 and is transferred to the raw material liquid 300 flowing into the space, so that the raw material liquid 300 is charged (charging process). ).

  By performing the charging step and the supplying step at the same time, the charged raw material liquid 300 flows out from the opening 119 of the effluent body 101 (outflow step).

  Moreover, the gas flow A along the flow of the raw material liquid 300 is discharged from the air blowing port 131 by the air blowing means 103 (air blowing process).

  Here, the raw material liquid 300 flowing out from the opening 119 forms a liquid pool 303 that covers the opening 119 and hangs down from the front end 116. The liquid pool 303 is formed for each of the plurality of openings 119, and the raw material liquid 300 hangs down from the tip of the liquid pool 303 (see FIG. 3). By forming the liquid reservoir 303 in this way, it is possible to suppress the generation of ion wind and improve the quality of the manufactured nanofiber 301.

  Further, the gas flow A pushes out the solvent vapor including the vicinity of the liquid reservoir 303 without greatly affecting the liquid reservoir 303.

  Next, the nanofiber 301 is manufactured by an electrostatic stretching phenomenon acting on the raw material liquid 300 that has flew in the space to some extent (a nanofiber manufacturing process). Here, the raw material liquid 300 flows out in a strong charged state (high charge density) without being influenced by the ion wind, and the raw material liquid 300 flying from each opening 119 flows out in a thin state without being collected. Thereby, most of the raw material liquid 300 is changed to the nanofiber 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 with a small wire diameter are manufactured. Further, the gas stream A pushes and bends the flight path of the raw material liquid 300 and the nanofiber 301 while discharging the solvent vapor from the flight path, so that the flight path becomes longer, and the evaporation of the solvent is further promoted to cause the electrostatic stretching phenomenon. Prompt.

  In this state, the nanofiber 301 is attracted to the deposition member 151 by an electric field generated between the charging electrode 121 disposed behind the deposition target member 151 and the outflow body 101 (attraction process).

  On the other hand, the air flow A is sucked in substantially uniformly throughout the Y-axis direction while maintaining the curtain state by the suction means 104 (intake stroke).

  Next, the nanofiber 301 is deposited and collected on the member 151 to be deposited (collecting step). Since the member 151 to be deposited is slowly transferred by the transfer means 152, the nanofiber 301 is also collected as a long belt-like member extending in the transfer direction.

  By using the nanofiber manufacturing apparatus 100 configured as described above and carrying out the above nanofiber manufacturing method, the flying of the raw material liquid 300 and the nanofiber 301 is not disturbed by the gas flow A, and the solvent vapor is efficient. It is possible to manufacture high-quality nanofibers 301 while being well discharged and maintaining high production efficiency.

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

DESCRIPTION OF SYMBOLS 100 Nanofiber manufacturing apparatus 101 Outflow body 102 Charging means 103 Air blowing means 104 Air intake means 105 Collection means 106 Supply means 107 Attraction means 113 Reservoir 116 Front end part 117 Side surface part 118 Outflow hole 119 Opening part 121 Charging electrode 122 Charging power supply 131 Air outlet 132 Buffer 133 Generation source 141 Inlet port 142 Vacuum chamber 143 Intake source 145 Guide unit 151 Deposited member 152 Transfer unit 153 Roll 300 Raw material liquid 301 Nanofiber

Claims (7)

A nanofiber manufacturing apparatus for manufacturing nanofibers by electrically stretching a raw material liquid in a space,
An outflow body having a plurality of outflow holes for allowing the raw material liquid to flow out in one direction into the space, the openings of the outflow holes being arranged in an array range that is an elongated strip-like virtual two-dimensional range;
Charging means for charging the raw material liquid flowing out from the effluent,
A blowing means for generating a curtain-like gas flow that flows along the raw material liquid in the same direction as the outflow direction, which is a direction in which the raw material liquid flows out from the outflow body, and extends substantially uniformly over the entire longitudinal direction of the arrangement range; A nanofiber manufacturing apparatus comprising: further,
2. The nanofiber manufacturing apparatus according to claim 1, further comprising an air intake unit configured to substantially uniformly intake the curtain-like gas flow generated by the air blowing unit over the entire longitudinal direction of the arrangement range. The air intake means includes an air intake port arranged to extend over the entire longitudinal direction of the arrangement range,
The nanofiber manufacturing apparatus according to claim 2, wherein an opening area of the intake port in a portion where the pressure for intake air is low is smaller than an opening area in a portion where the pressure is relatively high. The blower means includes a blower opening arranged to spread over the entire longitudinal direction of the arrangement range,
The nanofiber manufacturing apparatus according to claim 2, wherein an opening area of the air blowing port in a portion where the pressure of the gas flow is high is smaller than an opening area of a portion where the pressure is relatively low. further,
The nanofiber manufacturing apparatus according to claim 2, further comprising guide means for guiding the gas sucked by the suction means to the blower means. further,
A member to be deposited that collects nanofibers that are spread over the entire longitudinal direction of the array range and are manufactured in space;
The nanofiber manufacturing apparatus according to claim 1, further comprising a transfer unit that relatively transfers the outflow body and the deposition target member in a direction intersecting the longitudinal direction. A nanofiber manufacturing method for manufacturing a nanofiber by electrically stretching a raw material liquid in a space,
An outflow step of causing the raw material liquid to flow out in one direction into the space from the outflow body in which the openings of the plurality of outflow holes are arranged in an array range which is a virtual two-dimensional range of elongated strips;
A charging step of charging the raw material liquid flowing out of the effluent by a charging means;
The blowing means generates a curtain-like gas flow that flows along the raw material liquid in the same direction as the outflow direction, which is the direction in which the raw material liquid flows out from the outflow body, and extends substantially uniformly over the entire longitudinal direction of the arrangement range. The nanofiber manufacturing method including a ventilation process.

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