JP2011219875A - Nanofiber production apparatus and nanofiber production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a high-quality nanofiber having less variation by stabilizing and adjusting the shape of feedstock solution injected into the space.SOLUTION: A nanofiber production apparatus comprises: a guide 111 for guiding feedstock solution 300 alongside; a feeder 115 for feeding the feedstock solution to a guide face section 112 of the guide; a first discharger 131 for discharging a gas flow that forces the feedstock solution 300 flowing along the guide face section 112 against the guide 111; a charging electrode 121 disposed apart from the guide 111 at a predetermined distance; and a charging power supply 122 for applying a predetermined voltage between the guide 111 and the charging electrode 121.

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. The electrostatic stretching phenomenon occurs geometrically in succession in the space, and thereby nanofibers made of a resin having a diameter of submicron order or nano order are manufactured.

  When manufacturing nanofiber industrially using the electrostatic stretching phenomenon as described above, it is desired that the quality of the nanofiber is stable. For example, it is preferable that the nanofibers to be manufactured are thin, and the variation in the fiber diameter of the nanofibers manufactured at one time is suppressed as much as possible, and there is no variation over time. Moreover, when manufacturing a nonwoven fabric by depositing nanofibers, it is preferable that spatial variations of the manufactured nanofibers are eliminated as much as possible, and variations in the thickness of the nonwoven fabric can be suppressed.

  Patent Document 1 discloses an electrostatic stretching phenomenon by finely dispersing the raw material liquid flowing out into the space by discharging the raw material liquid from the center nozzle of the two-fluid nozzle and discharging the gas flow from the surrounding nozzles. A technique is described that can be promoted to obtain a nonwoven fabric of uniform quality.

Special table 2008-525669 gazette

  However, when nanofibers are manufactured using a two-fluid nozzle, when the raw material liquid flowing out from the nozzle is dispersed into fine raw material liquid particles, the shape of the raw material liquid particles varies, and the charge amount varies. There are concerns that arise. In some cases, there is a concern that particles of the raw material liquid having a size that cannot be sufficiently charged are generated. In such a state, the quality of the manufactured nanofiber is not stable.

  Therefore, as a result of diligent research and experiments, the inventor of the present application has developed a phenomenon in which the raw material liquid has a spindle-shaped shape downward from the nozzle tip, thereby forming a so-called tailored cone with a very small radius of curvature. As a result, electric charges are concentrated on the pointed portion of the raw material liquid, and the electrostatic stretching phenomenon has been found to be promoted. Furthermore, by maintaining the shape of this tailor cone, it has been found that the electric charge continuously concentrates on the pointed portion of the raw material liquid, and the substantially uniform charged state of the raw material liquid can be maintained. In other words, when the two-fluid nozzle is used, since the raw material liquid is dispersed without generating a tailor cone, the shape of the raw material liquid particles shredded due to the dispersion is not constant, and the curvature radius of the raw material liquid particles varies. Therefore, it is considered that the charged state fluctuates and the quality of the nanofiber is not stable.

  As a result of further experiments and researches, it was found that the degree of concentration of charges in the raw material liquid changes depending on the shape of the tailor cone.

  The present invention has been made on the basis of the above knowledge, and can actively form the shape of the raw material liquid that can be equated with the tailor cone, can stabilize the shape of the raw material liquid, and is manufactured. An object of the present invention is to provide a nanofiber manufacturing apparatus and a nanofiber manufacturing method capable of achieving both improvement and stabilization of fiber quality.

  In order to achieve the above object, a nanofiber manufacturing apparatus according to the present invention is a nanofiber manufacturing apparatus for manufacturing nanofibers by electrically stretching a raw material liquid in a space, A guide body provided with a guide surface portion to be guided, an end portion that is located at one end of the guide surface portion and allows the raw material liquid flowing along the guide surface portion to flow out into the space, and a raw material liquid on the guide surface portion of the guide body A supply body provided with a supply port for supplying gas, a first discharge body provided with a first discharge port for blowing out a gas flow that presses the raw material liquid flowing along the guide surface portion against the guide body, the guide body and a predetermined body It is characterized by comprising a charging electrode arranged at an interval, and a charging power source for applying a predetermined voltage between the guide body and the charging electrode.

  According to this, the raw material liquid flowing along the guide surface portion is pressed by the air flow discharged from the first discharge port, and the raw material liquid is thinly extended. And in the said state, since a raw material liquid flows out in space from an edge part, a raw material liquid becomes a film | membrane shape corresponding to the shape of an edge part. The film shape in this space becomes a so-called tailor cone, so that charges concentrate on the pointed portion of the raw material liquid, and the raw material liquid can have a high charge density. The film-shaped raw material liquid is decomposed into a plurality of string-shaped raw material liquids by an electrostatic stretching phenomenon, and nanostrands are manufactured by repeatedly generating the electrostatic stretching phenomenon in the string-shaped raw material liquids. When the film-shaped raw material liquid is thin, the string-shaped raw material liquid becomes thin, so that the manufactured nanofibers become thin. In addition, when the film-shaped raw material liquid is thin, charges are likely to concentrate, and the raw material liquid can be made to have a higher charge density. Therefore, the electrostatic stretching phenomenon repeatedly occurs, and the manufactured nanofibers become thin.

  As described above, according to the present invention, the raw material liquid can be made to have a high charge density in a stable state, and a thin nanofiber can be manufactured. In addition, since the film shape serving as a substitute for the tailor cone can be positively adjusted without accidentally leaving it like the tailor cone, it becomes possible to produce high quality nanofibers in a stable state over time. It is also possible to suppress spatial variations in the quality of the nanofiber.

  Further, the guide surface portion and the end edge portion may be ring-shaped.

  According to this, the film-shaped raw material liquid formed in the space can be brought into an endless state with no end in the direction intersecting the outflow direction. That is, the raw material liquid flowing out from the end edge portion has a thin cylindrical shape. Therefore, there is no specific part in the raw material liquid that is decomposed in a string shape in the direction crossing the outflow direction, and it becomes possible to manufacture nanofibers having no variation in quality.

  Furthermore, you may provide the 2nd discharge body provided with the 2nd discharge port which blows off the gas flow which adjusts the shape of the raw material liquid immediately after flowing into the space from the said guide body.

  According to this, it is possible to prevent the film-form raw material liquid from spreading along the shape of the edge portion in the direction intersecting with the guide surface portion, and increase the thickness of the film-form raw material liquid.

  Moreover, the shape provided with the sharp ridgeline part may be sufficient as the said edge part.

  According to this, since the raw material liquid can flow out from the ridgeline, it is possible to suppress the raw material liquid from spreading by the edge portion and increasing the thickness of the film-shaped raw material liquid.

  In order to achieve the above object, a nanofiber manufacturing method according to the present invention is a nanofiber manufacturing method for manufacturing a nanofiber by electrically stretching a raw material liquid in a space, and is provided in a supply body. The raw material liquid supplied from the supply port is guided along the guide surface portion provided in the guide body, and flows along the guide surface portion by the gas flow discharged from the first discharge port provided in the first discharge body. The raw material liquid is pressed against the guide body, and the raw material liquid flowing along the guide surface portion from the edge located at one end of the guide surface portion is allowed to flow into the space, and is arranged at a predetermined interval from the guide body. The raw material liquid is charged by a charging electrode that is charged and a charging power source that applies a predetermined voltage between the guide body and the charging electrode.

  According to this, the raw material liquid flowing along the guide surface portion is pressed by the air flow discharged from the first discharge port, and the raw material liquid is thinly extended. And in the said state, since a raw material liquid flows out in space from an edge part, a raw material liquid becomes a film | membrane shape corresponding to the shape of an edge part. The film shape in this space becomes a so-called tailor cone, so that charges concentrate on the raw material liquid, and the raw material liquid can be made to have a high charge density. The film-shaped raw material liquid is decomposed into a plurality of string-shaped raw material liquids by an electrostatic stretching phenomenon, and nanostrands are manufactured by repeatedly generating the electrostatic stretching phenomenon in the string-shaped raw material liquids. When the film-shaped raw material liquid is thin, the string-shaped raw material liquid becomes thin, so that the manufactured nanofibers become thin. Further, if the film-shaped raw material liquid is thin, charges are likely to concentrate, and the raw material liquid can be made to have a high charge density. Therefore, the electrostatic stretching phenomenon occurs repeatedly, and the manufactured nanofibers become thin.

  As described above, according to the present invention, the raw material liquid can be made to have a high charge density in a stable state, and a thin nanofiber can be manufactured. In addition, since the film shape serving as a substitute for the tailor cone can be positively adjusted without accidentally leaving it like the tailor cone, it becomes possible to produce high quality nanofibers in a stable state over time. It is also possible to suppress spatial variations in the quality of the nanofiber.

  According to the present invention, the raw material liquid can be formed in a thin film shape, and the shape can be controlled to some extent. Therefore, high-quality nanofibers can be manufactured stably in space and time.

It is a perspective view which shows a nanofiber manufacturing apparatus. It is a top view which shows a discharge | release means in a cross section. It is a perspective view which cuts out and shows a part of discharge | release means which removed the 1st discharge body. It is a figure which shows the relationship between the discharge | release means, charging means, and attracting means when there is no 2nd discharge body. It is a perspective view which shows another aspect of the discharge | release means. It is a perspective view which shows the nanofiber manufacturing apparatus concerning other embodiment. It is a perspective view which shows the front-end | tip part of the discharge | release means concerning other embodiment in a cross section. It is a perspective view which shows another aspect of the discharge | release means.

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

(Embodiment 1)
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 a discharge means 101, an attraction means 104, and a collection device. Means 128, raw material supply means 107, gas flow generation means 108, and charging means 102 are provided.

  FIG. 2 is a plan view showing the discharge means in cross section.

  FIG. 3 is a perspective view in which a part of the discharge means from which the first discharge body has been removed is cut away.

  As shown in these drawings, the discharge means 101 is a device that charges the raw material liquid 300 and discharges the charged raw material liquid 300 into the space, and includes a supply body 115, a guide body 111, and a first discharge. A body 131 and a second discharge body 132 are provided.

  As shown in FIG. 1, the supply body 115 is a member that is connected to the raw material supply means 107 and supplies the raw material liquid 300 supplied from the raw material supply means 107 to the guide body 111. A mouth 151 is provided.

  In the case of the present embodiment, the supply body 115 has a hollow cylindrical shape with a triangular cross section, and includes a storage tank 114 that stores the raw material liquid therein. Further, the supply body 115 is provided with an elongated slit-shaped supply port 151 at the lower portion, and stores the raw material liquid 300 supplied from the raw material supply means 107 in a storage tank 114 formed therein, The raw material liquid 300 is supplied to the guide body 111 by pressure (which may include gravity).

  The raw material supply means 107 can be exemplified by a device comprising a tank for storing the raw material liquid 300, a pump capable of conveying the raw material liquid 300, and a guide tube for guiding the raw material liquid 300. .

  The guide body 111 includes a guide surface portion 112 that guides the raw material liquid 300 along, and an edge portion 113 that is positioned at one end of the guide surface portion 112 and allows the raw material liquid 300 flowing along the guide surface portion 112 to flow out into the space. I have. The guide body 111 is a member for resisting the force by which the raw material liquid 300 is pressed by the gas flow discharged from the first discharge port 133. In the present embodiment, the guide body 111 is a rod-shaped member having a triangular cross section, and a portion corresponding to one surface of the outer peripheral surface of the member functions as the guide surface portion 112. Therefore, the guide surface portion 112 has an elongated rectangular plate shape. Moreover, the edge part 113 is a part applicable to the vertex of the cross section of the triangle in the guide body 111, and is provided with the sharp ridgeline part.

  Thus, by providing the edge portion 113 with the sharp edge portion, it is possible to suppress the phenomenon that the raw material liquid 300 flowing along the guide surface portion 112 spreads along the edge portion 113 due to its viscosity. It is possible to reduce the thickness of the film-like raw material liquid 300 flowing out into the water.

  Moreover, the guide body 111 also functions as an electrode for supplying electric charge to the flowing out raw material liquid 300, and at least a part of a portion in contact with the raw material liquid 300 is formed of a conductive member. In the case of the present embodiment, the guide body 111 is formed integrally with the supply body 115, and the entire guide body 111 and the supply body 115 are made of metal. In addition, if the kind of metal is provided with electroconductivity, it will not specifically limit, Arbitrary materials, such as brass and stainless steel, can be selected.

  As shown in FIG. 1, the first discharge body 131 is a member that is connected to the gas flow generation means 108 and discharges a gas flow supplied from the gas flow generation means 108, and the raw material liquid that flows along the guide surface portion 112. This is a member provided with a first discharge port 133 that blows out a gas flow that presses 300 against the guide body 111.

  In the case of the present embodiment, the first discharge body 131 discharges a gas flow that presses against the guide body 111 over the whole of the raw material liquid 300 flowing along the elongated plate-shaped guide surface section 112, and thus the first discharge body 131 is long along the guide surface section 112. It has a shape. The first discharge port 133 has an elongated slit shape having the same length as the supply port 151. A part of the supply body 115 functions as the first discharge body 131, and the first discharge port 133 is formed so as to be surrounded by the supply body 115 and the first discharge body 131. Accordingly, it is possible to discharge a gas flow so as to press the raw material liquid 300 against the guide body 111 from an oblique direction along the shape of the supply body 115 having a triangular cross section.

  The gas flow generation means 108 can be exemplified by a device composed of a compressor for compressing a gas such as air and a pressure feed pipe for pressure feeding the gas.

  The second discharge body 132 is a member provided with a second discharge port 134 that blows out a gas flow that adjusts the shape of the raw material liquid 300 immediately after flowing out of the guide body 111 into the space. It is a member for discharging a gas flow that is arranged on the side opposite to the body 131 and adjusts the shape of the raw material liquid 300 flowing out from the guide body 111 into the space.

  In the case of the present embodiment, the second discharge body 132 is a film-form raw material together with the gas flow discharged from the first discharge port 133 over the entire raw material liquid 300 flowing out from the end edge portion 113 of the elongated plate-shaped guide surface portion 112. In order to discharge a gas flow that keeps the shape of the liquid 300 in a thin state, it has a long shape along the guide body 111, and the second discharge port 134 has an elongated slit shape having the same length as the first discharge port 133. It has become. The second discharge body 132 is in communication with the first discharge body 131, and the gas flow supplied from the gas flow generation means 108 is supplied via the first discharge body 131. Further, a part of the supply body 115 and a part of the guide body 111 also function as the second discharge body 132, and the second discharge port 134 is surrounded by the guide body 111 and the second discharge body 132. Is formed. As a result, a gas flow flows along the shape of the supply body 115 (the guide body 111 formed obliquely) having a triangular cross section so as to support the raw material liquid 300 that has passed through the edge 113 from the oblique direction. . That is, the gas flow that supports and supports from the opposite side flows so that the raw material liquid 300 that has passed through the end edge portion 113 flows out onto the extension line of the guide surface portion 112 even if pressed against the gas flow discharged from the first discharge port 133. .

  The attracting means 104 is an apparatus for attracting the nanofiber 301 manufactured in the space to the collecting means 128. The attracting means 104 uses a gas flow to attract the nanofiber 301 to a predetermined position (gas flow method) or the fact that the nanofiber 301 flying in the space is charged, A method (electric field method) of generating and attracting the nanofiber 301 to a predetermined position can be adopted, and a gas flow method and an electric field method may be used together.

  In the case of the present embodiment, as shown in FIG. 1, the attracting means 104 includes an attracting electrode 143 that is longer than the ejecting means 101 at a position away from the ejecting means 101 by a predetermined distance. The attracting electrode 143 is a conductive member connected to the attracting power source 141 and applied with a predetermined potential, and attracts the nanofiber 301 by an electric field generated from the attracting electrode 143. The attracting unit 104 includes a suction unit 142. The suction means 142 is a device that sucks gas from a large number of through holes provided in the thickness direction of the attracting electrode 143 to generate a gas flow, and attracts the nanofiber 301 to a predetermined position.

  The collecting means 128 is a device that collects the nanofibers 301 manufactured in the space. In the case of the present embodiment, the collection means 128 includes a member to be deposited 126 and a transfer means 129.

  The member 126 to be deposited is a member that deposits and collects nanofibers 301 in which the raw material liquid 300 discharged from the discharge means 101 has changed due to the electrostatic stretching phenomenon.

  In the case of the present embodiment, the member 126 to be deposited is a net-like sheet through which the gas flow generated by the attracting means 104 passes, and the surface of the Teflon (on the surface so that the nanofibers 301 deposited from the member 126 to be deposited can be easily peeled off. (Registered trademark) coat is given.

  The transfer unit 129 is a device that relatively moves the discharge unit 101 and the deposition target member 126. In the case of the present embodiment, the supply body 115 is fixed, and only the member to be deposited 126 is moved. Specifically, the transfer means 129 is capable of moving the deposition member 126 together with the nanofibers 301 that are pulled out from the roll 127 while winding up the elongated deposition member 126.

  The transfer means 129 may not only move the deposition member 126 but also move the discharge means 101 with respect to the deposition member 126. The transfer means 129 moves the deposition member 126 in a certain direction. Arbitrary operation states such as reciprocating the discharge means 101 can be adopted.

  The charging unit 102 is a device that charges the raw material liquid 300 by applying an electric charge so that an electrostatic stretching phenomenon occurs. In the case of the present embodiment, the charging unit 102 includes a charging electrode 121 and a charging power source 122.

  As shown in FIG. 2, the charging electrode 121 is arranged at a predetermined interval from the guide body 111, and induces an electric charge to the guide body 111 by itself becoming a high voltage or a low voltage with respect to the guide body 111. It is a member provided with the electroconductivity for this. In the case of the present embodiment, the leading edge of the first ejection body 131 functions as the charging electrode 121 and is disposed in parallel with the guide surface portion 112 of the guide body 111. The charging electrode 121 is grounded. When a positive voltage is applied to the guide body 111, a negative charge is induced in the charging electrode 121, and when a negative voltage is applied to the guide body 111, the charging electrode 121 is charged. In this case, a positive charge is induced.

  As in the present embodiment, the guide body 111 and the charging electrode 121 are arranged at positions relatively close to each other, so that the voltage between the guide body 111 and the charging electrode 121 is changed. Can be sufficiently charged even if they are set lower than the case where they are arranged close to each other. Further, the charged raw material liquid 300 is attracted in the direction of the charging electrode 121 and tries to fly toward the charging electrode 121, but the gas flow that flows between the guide body 111 and the charging electrode 121 (first discharge body 131). Since the flight direction is changed, the raw material liquid 300 can be prevented from adhering to the charging electrode 121.

  The charging power source 122 is a power source that can apply a high voltage to the guide body 111. In general, the charging power source 122 is preferably a DC power source. In particular, when the charged polarity of the nanofiber 301 is not affected, the charged nanofiber 301 is used to attract the nanofiber 301 with an electrode to which a reverse polarity potential is applied. Is preferably a DC power supply.

  If one electrode of the charging power source 122 is set to the ground potential and the charging electrode 121 is grounded as in the present embodiment, the relatively large charging electrode 121 can be set to the ground state, which improves safety. It becomes possible to contribute to.

  Alternatively, a power source may be connected to the charging electrode 121 to maintain the charging electrode 121 at a high voltage, and the guide body 111 may be grounded to apply a charge to the raw material liquid 300. Further, the charging electrode 121 and the guide body 111 may be in a connection state in which neither of them is grounded.

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

  First, the raw material liquid 300 is supplied to the supply body 115 by the raw material supply means 107. As described above, the raw material liquid 300 is filled in the storage tank 114 of the supply body 115.

  Here, the resin constituting the nanofiber 301, and the solute dissolved or dispersed in the raw material liquid 300 is 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 Coalesce, polycarbonate, polyarylate, polyester carbonate, polyamide, aramid, polyimide, polycaprolactone, polylactic acid, polyglycolic acid Collagen, polyhydroxybutyric acid, 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 for the raw material liquid 300 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 300 used for this invention is not limited to employ | adopting the said solvent.

Furthermore, an inorganic solid material may be added to the raw material liquid 300. Examples of the inorganic solid material include oxides, carbides, nitrides, borides, silicides, fluorides, sulfides, and the like. It is preferable to use an oxide. Examples of the oxide include Al ₂ O ₃ , SiO ₂ , TiO ₂ , Li ₂ O, Na ₂ O, MgO, CaO, SrO, BaO, B ₂ O ₃ , P ₂ O ₅ , SnO ₂ , ZrO ₂ , K. ₂ O, Cs ₂ O, ZnO, Sb ₂ O ₃ , As ₂ O ₃ , CeO ₂ , V ₂ O ₅ , Cr ₂ O ₃ , MnO, Fe ₂ O ₃ , CoO, NiO, Y ₂ O ₃ , Lu ₂ 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 300 of this invention is not limited to the said additive.

  The mixing ratio of the solvent and the solute in the raw material liquid 300 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%. Preferably the solute is 5-30%.

  Next, the raw material liquid 300 supplied from the supply port 151 provided in the supply body 115 is guided along the guide surface portion 112 provided in the guide body 111 (guide process).

  On the other hand, the raw material liquid 300 flowing along the guide surface portion 112 is pressed against the guide body 111 by the gas flow discharged from the first discharge port 133 provided in the first discharge body 131 (pressing step).

  As described above, the raw material liquid 300 is compressed by the guide body 111 and the gas flow, and becomes a thin film on the surface of the guide surface portion 112.

  Furthermore, the charging body 122 causes the guide body 111 to be set to a positive or negative high voltage via the supply body 115. As a result, charges are concentrated on the edge portion 113 of the guide body 111 facing the charging electrode 121, the charges are transferred to the raw material liquid 300 flowing along the guide surface portion 112, and the raw material liquid 300 is charged (charging process).

  Here, since the charge is imparted to the raw material liquid 300 that is formed into a thin film by the gas flow discharged from the guide body 111 and the first discharge port 133, the raw material liquid 300 can be charged with a high charge density. Become.

  Next, the raw material liquid 300 flowing along the guide surface portion 112 from the end edge portion 113 positioned at one end of the guide surface portion 112 is caused to flow out into the space (outflow process).

  In the present embodiment, the shape of the raw material liquid 300 immediately after flowing into the space by the gas flow discharged from the second discharge port 134 disposed on the opposite side of the first discharge port 133 with respect to the raw material liquid 300 is a thin film. As a result, the raw material liquid 300 can be maintained in a high charge density state.

  Here, the raw material liquid 300 flowing out from the edge portion 113 of the guide body 111 has a film shape that hangs down from the edge portion 113. This film-form raw material liquid 300 changes into a plurality of thin string-like (rope-like) raw material liquid 300 extending in the vertical direction due to a high charge density as it flies through the space. And the nanofiber 301 is manufactured when an electrostatic stretching phenomenon acts on each of the string-like raw material liquids 300 (nanofiber manufacturing process).

  Here, since the raw material liquid 300 changes from a thin film state to a string state, the raw material liquid 300 flies through the space in a very thin state. On the other hand, since the raw material liquid 300 flows out in a strong charged state (high charge density), electrostatic stretching occurs over many orders, and high-quality nanofibers 301 with a small wire diameter are manufactured in large quantities. The

  In this state, the nanofiber 301 is attracted to the deposited member 126 by the attracting means 104 arranged behind the deposited member 126 (attracting step).

  As described above, the nanofiber 301 is deposited on the deposition target member 126. Since the member 126 to be deposited is slowly transferred by the transfer means 129, the nanofiber 301 is also collected as a long belt-like member extending in the transfer direction (collecting step).

  By using the nanofiber manufacturing apparatus 100 configured as described above and performing the above nanofiber manufacturing method, high-quality nanofibers 301 are manufactured in a uniform and stable state without causing spatial unevenness. It becomes possible.

  The present invention is not limited to the above embodiment.

  For example, as shown in FIG. 4, the charging electrode 121 may be arranged at a position relatively far from the guide body 111. Further, in the case of the nanofiber manufacturing apparatus 100 having such an aspect, the charging electrode 121 also functions as the attracting electrode 143, and the charging power source 122 functions as the attracting power source 141. That is, the charging unit 102 and the electric field type attracting unit 104 may be realized by a single device.

  As shown in FIG. 5, the discharge means 101 includes a plate-shaped guide body 111 and a cylindrical supply body 115, and a supply body 115 arranged in a line in the length direction of the guide body 111. The first discharge body 131 including the elongated slit-shaped first discharge port 133 extending in the length direction of the guide body 111 may be used.

  Even in this case, the raw material liquid 300 discharged from the supply port 151 of the supply body 115 is supplied to the guide body 111 and flows along the guide surface portion 112. The gas flow blown out from the first discharge port 133 of the first discharge body 131 presses the raw material liquid 300 flowing along the guide surface portion 112 against the guide body 111. The raw material liquid 300 pressed into a film shape flows out from the end edge portion 113 of the guide body 111 into the space.

  As described above, the same operational effects as described above can be obtained. Further, in this case, even if there is a variation in the amount of the raw material liquid 300 supplied from the plurality of supply bodies 115, since the raw material liquid 300 is thinned by the gas flow, these variations are suppressed to a negligible level. It becomes possible.

(Embodiment 2)
Next, another embodiment of the nanofiber manufacturing apparatus 100 according to the present invention will be described.

  FIG. 6 is a perspective view showing a nanofiber manufacturing apparatus according to another embodiment.

  As shown in the figure, a nanofiber manufacturing apparatus 100 is an apparatus that manufactures nanofibers 301 by electrically stretching a raw material liquid 300 in a space, and includes a discharge means 101, an attraction means 104, a raw material. A supply unit 107, a gas flow generation unit 108, and a charging unit 102 are provided.

  Since the configuration other than the discharge means 101 is the same as that in the above embodiment, a description thereof is omitted here.

  FIG. 7 is a perspective view showing the tip of the discharge means in section.

  As shown in the figure, the discharge means 101 is a device that charges the raw material liquid 300 and discharges the charged raw material liquid 300 in a cylindrical shape, and has a rod-like shape arranged along the central axis of the discharge means 101. A second discharge body 132, a double tubular supply body 115 arranged to surround the second discharge body 132 at a predetermined distance, and a guide body 111 extending to the inner pipe of the supply body 115; And a tubular first discharge body 131 disposed so as to surround the supply body 115 at a predetermined distance.

  The supply body 115 is a double tubular member that is connected to the raw material supply means 107 and supplies the raw material liquid 300 supplied from the raw material supply means 107 to the guide body 111. The raw material liquid 300 is supplied to the guide body 111. An annular supply port 151 is provided.

  The guide body 111 is positioned at one end of the guide surface portion 112 and the cylindrical guide surface portion 112 that guides the raw material solution 300 along, and an annular shape that allows the raw material solution 300 flowing along the guide surface portion 112 to flow into the space. And an end edge portion 113. The guide body 111 is a member that resists the force by which the raw material liquid 300 is pressed by a gas flow discharged in a cylindrical shape from the first discharge port 133.

  The first discharge body 131 is a cylindrical member surrounding the supply body 115, and discharges a cylindrical gas flow that presses the raw material liquid 300 flowing in a cylindrical shape along the cylindrical guide surface portion 112 against the guide body 111. The annular first discharge port 133 is provided.

  The second discharge body 132 is a member provided with an annular second discharge port 134 that blows out a gas flow that adjusts the shape of the cylindrical raw material liquid 300 immediately after flowing out of the guide body 111 into the space. 101 is a rod-shaped member disposed on the central axis of 101.

  As described above, the guide surface portion 112 has a cylindrical shape, and the raw material liquid 300 is supplied from the supply body 115 so as to surround the guide surface portion 112, and from the first discharge port 133 of the first discharge body 131 toward the guide surface portion 112. By spraying a gas flow so as to surround the guide surface portion 112, the raw material liquid 300 flows in a thin cylindrical shape and flows on the surface of the guide surface portion 112. Then, the raw material liquid 300 flows out from the annular end edge portion 113 into the space with the thin cylindrical shape. That is, the raw material liquid 300 flows into the space in an endless state with no end in the direction intersecting the outflow direction.

  On the other hand, a high voltage is applied between the guide body 111 and the charging electrode 121, and the raw material liquid 300 is charged with a high charge density.

  Therefore, the raw material liquid 300 is decomposed evenly in the circumferential direction into a string shape, and an electrostatic stretching phenomenon is efficiently generated, and nanofibers 301 with uniform quality in the circumferential direction are manufactured.

  In addition, this invention is not limited to the said embodiment. For example, the supply body 115 may be provided with a plurality of supply ports 151 that are separated by a partition as shown in FIG. 8 instead of the slit-shaped supply ports 151. In the case of the slit-shaped supply port 151, particularly when the length of the supply port 151 is increased, the force with which the raw material liquid 300 is pushed by the force of the gas flow is strong at the center in the length direction of the supply port 151, and at the end. A weakening phenomenon may occur. When such a phenomenon occurs, there is a possibility that the raw material liquid 300 moves to the left and right, and the thickness of the raw material liquid 300 flowing out into the space is different between the central portion and both ends of the supply port 151 in the length direction. There is. In the case of the slit-shaped supply port 151, the processing accuracy may not be sufficiently secured, and it becomes difficult to control the thickness of the raw material liquid 300 uniformly. Therefore, the supply port 151 of the supply body 115 is formed with a plurality of small openings, so that the supply amount of the raw material liquid 300 at the central portion and the end portion in the length direction of the supply body 115 is adjusted, and the raw material flowing out into the space The thickness of the liquid 300 can be made uniform.

  The shape of the supply port 151 is not limited to a semicircle, and may be a rectangle, a circle, or a triangle.

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

DESCRIPTION OF SYMBOLS 100 Nanofiber manufacturing apparatus 101 Discharge means 102 Charging means 104 Attraction means 107 Raw material supply means 108 Gas flow generation means 111 Guide body 112 Guide surface part 113 Edge part 114 Storage tank 115 Supply body 121 Charging electrode 122 Charging power source 126 Deposited member 127 Roll 128 Collecting means 129 Transfer means 131 First discharge body 132 Second discharge body 133 First discharge port 134 Second discharge port 141 Attracting power supply 142 Suction means 143 Attracting electrode 151 Supply port 300 Raw material liquid 301 Nanofiber

Claims (8)

A nanofiber manufacturing apparatus for manufacturing nanofibers by electrically stretching a raw material liquid in a space,
A guide body provided with a guide surface portion that guides the raw material liquid along, and an edge that is located at one end of the guide surface portion and allows the raw material liquid flowing along the guide surface portion to flow into the space;
A supply body provided with a supply port for supplying a raw material liquid to the guide surface portion of the guide body;
A first discharge body provided with a first discharge port for blowing out a gas flow that presses the raw material liquid flowing along the guide surface portion against the guide body;
A charging electrode disposed at a predetermined interval from the guide body;
A nanofiber manufacturing apparatus comprising: a charging power source that applies a predetermined voltage between the guide body and the charging electrode. The nanofiber manufacturing apparatus according to claim 1, wherein a part of the supply body functions as the first discharge body, and the first discharge port is formed by a part of the supply body and the first discharge body. further,
The nanofiber manufacturing apparatus according to claim 1, further comprising a second discharge body provided with a second discharge port for blowing out a gas flow for adjusting the shape of the raw material liquid immediately after flowing out of the guide body into the space. The nanofiber manufacturing apparatus according to claim 3, wherein a part of the supply body functions as the second discharge body, and the second discharge port is formed by a part of the supply body and the second discharge body. The nanofiber manufacturing apparatus according to any one of claims 1 to 4, wherein the guide surface part and the end edge part have an annular shape. The nanofiber manufacturing apparatus according to claim 1, wherein the end edge portion has a shape including a sharp ridge line portion. further,
A collection means for collecting nanofibers produced in space;
The nanofiber manufacturing apparatus according to claim 1, further comprising an attracting unit that attracts the nanofiber to the collecting unit. A nanofiber manufacturing method for manufacturing a nanofiber by electrically stretching a raw material liquid in a space,
Guide the raw material liquid supplied from the supply port provided in the supply body along the guide surface provided in the guide body,
While pressing the raw material liquid flowing along the guide surface portion against the guide body by the gas flow discharged from the first discharge port provided in the first discharge body,
Causing the raw material liquid flowing along the guide surface portion to flow out into the space from an edge located at one end of the guide surface portion;
A nanofiber manufacturing method in which a raw material liquid is charged by a charging electrode disposed at a predetermined interval from the guide body, and a charging power source that applies a predetermined voltage between the guide body and the charging electrode.

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