JP2009280923A - Method and device for doubling nanofiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for doubling nanofibers, capable of stably producing a uniform yarn comprising the nanofibers produced by an electric charge-induced spinning method and having a high strength in good productivity at a low cost. <P>SOLUTION: Provided is the method for doubling the nanofibers, including the steps of feeding a core fiber 6 along a prescribed route, flowing out a raw material solution 20 comprising a polymer dissolved in a solvent from small holes 10 disposed around the core fiber 6 of a spinning head 3, forming an electric field between the small holes 10 and an electric field-producing electrode 4 disposed around the small holes 10 with the first high voltage-generating means 21 to charge an electric charge to the raw material solution 20 flowed out from the small holes 10, electrostatically exploding the raw material solution 20 flowed out from the small holes 10 to produce the nanofibers 2, and swirling and flowing the produced nanofibers 2 to a collection electrode 5 arranged at a prescribed position in the core fiber 6-moving direction or its opposite direction to entwine the core fiber 6 with the produced nanofibers 2, and then recovering the obtained yarn 8. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a nanofiber combination method and apparatus for producing nanofibers made of a polymer material and using them as yarns.

  Conventionally, a charge-induced spinning method (also referred to as an electrospinning method) is known as a method for producing a nanofiber having a submicron-scale diameter made of a polymer material. In the conventional charge-induced spinning method, a polymer solution is supplied to a needle-like nozzle to which a high voltage is applied, and the charge is charged to the polymer solution that flows out linearly from the needle-like nozzle. As the solvent in the charged linear polymer solution evaporates, the distance between the charged charges is reduced, the Coulomb force acting between the charged charges is increased, and the Coulomb force is linear polymer solution. When the surface tension of the linear polymer solution is overcome, a phenomenon occurs in which the linear polymer solution is stretched explosively, and this phenomenon called electrostatic explosion is repeated geometrically as primary, secondary, or even tertiary. As a result, a nanofiber made of a polymer having a submicron diameter is manufactured.

  In the conventional charge induction spinning method, only one to several nanofibers are produced from the tip of one nozzle, and thus there is a problem that productivity does not increase. Therefore, as a method for producing a large amount of nanofibers, a method using a plurality of nozzles has been proposed (see, for example, Patent Document 1). In this Patent Document 1, a polymer solution stored in a barrel is supplied to a number of needle-shaped nozzles charged by a pump and discharged to create a large amount of nanofibers, which have a different polarity from the nozzles. A technique for producing a highly porous polymer web having a very high porosity in which nanofibers are laminated in a three-dimensional network structure is disclosed by collecting and transporting them with a charged collector. Increased from an experimental level to a practical level.

Conventionally, nanofibers produced by the charge-induced spinning method have been manufactured as webs, and have been used in various ways such as artificial leather, filters, diapers, sanitary napkins, adhesive spinning agents, wiping cloths, artificial blood vessels, and bone fixation devices. It is difficult to obtain mechanical properties of 10 MPa or more, and there is a limit to the use in a wide range of applications. When trying to improve the mechanical properties by making the nanofiber web manufactured in this way into continuous yarns, It was pointed out that there was a problem that a short fiber was cut by cutting to a certain length and a separate spinning process was required to produce spun yarn from this short fiber. A technique for continuously producing yarn using a fiber web has been proposed (see, for example, Patent Document 2). In this Patent Document 2, nanofibers are spun on a static surface of water or an organic solvent in a collector charged in a polarity opposite to that of the nozzle from the nozzles charged in a row and deposited in a web. The web to be deposited is pulled up by a rotating roller rotating at a constant linear velocity from a point 1 cm or more away from one end side viewed in the row direction of the nozzles to form a continuous yarn, which is pressed, stretched, dried and wound. A continuous yarn is obtained by taking off. In addition, continuous yarn can be twisted.
JP 2002-201559 A JP-T-2006-507428

  However, the technique described in Patent Document 2 is generated from each nozzle due to the spread of the deposition area while generating nanofibers directly from each nozzle and statically depositing them at a position corresponding to the nozzle on the collector. Nanofibers are entangled with each other to form a narrow web, and the nanofibers are pulled out from one end of the web, and the continuous nanofibers are pulled out to the other end of the web and focused on a continuous yarn. Therefore, while the deposition of nanofibers spun from each nozzle is static and almost equivalent, the deposition is close to the pulling side because the pulling action tends to concentrate in the deposition area close to the pulling side. There may be a difference in the extraction amount of the nanofiber between the deposition area and the distant deposition area. There is a problem that a non stable difficult to properly control the thickness and mechanical properties of continuous yarn by being drawn in a state that caused the difference in. Further, there is a problem that it is necessary to suppress the drawing speed to make the drawing action evenly extend to the deposition area far from the drawing side, and it is difficult to manufacture in large quantities.

  Therefore, in order to solve such a problem, a nanofiber spinning device 41 as shown in FIG. 5 has been considered. In FIG. 6, the nanofiber spinning device 41 includes a nanofiber generating unit 42, a collecting electrode 43, a core yarn supplying unit 44, and a collecting unit 45. The nanofiber generating means 42 is rotatably supported around a vertical axis, and has a cylindrical container 46 in which a large number of small holes 47 are formed on the peripheral surface, and a polymer solution supply for supplying the polymer solution into the cylindrical container 46. Means (not shown), first high voltage generating means 48 for applying a high voltage to the cylindrical container 46, rotational driving means (not shown) for rotationally driving the cylindrical container 46 in the direction of arrow a, and cylindrical container 46 and a second high voltage generating means 50 for applying a high voltage of the same polarity as the cylindrical container 46 to the reflective electrode 49, and flows out from the small hole 47 of the cylindrical container 46. The polymer solution is stretched by centrifugal force and electrostatic explosion to generate nanofibers 51, and the generated nanofibers 51 are made to flow while turning toward the lower side of the cylindrical container 46 by the reflecting electrode 49. Has been.

  The collecting electrode 43 has a disk shape, is coaxially and rotatably disposed below the cylindrical container 46, and has a through-hole 52 through which the nanofiber 51 converged at the center thereof passes. The third high voltage generating means 53 is configured to apply a high voltage having a polarity opposite to that of the cylindrical container 46 and the reflective electrode 49, and the collection electrode 43 is moved to the arrow by the rotation driving means (not shown). It is configured to be driven to rotate in the direction of arrow b opposite to the direction a. The core yarn supplying means 44 is disposed above the nanofiber generating means 42 and is configured to feed the core yarn 54 and supply it downward from directly above the axial center position of the cylindrical container 46. The collecting means 45 is a collecting electrode. The yarn 55 disposed below the wire 43 and twisted and converged is passed through the through-hole 52 of the collecting electrode 43 and collected.

  In the above configuration, when the cylindrical container 46 is rotationally driven at a high speed while supplying the polymer solution into the cylindrical container 46 of the nanofiber generating means 42, centrifugal force is applied to the charged polymer solution in the cylindrical container 46. Acting, flowing out from each small hole 47 and being stretched by the action of centrifugal force to produce a thin polymer linear body, and further being explosively stretched by an electrostatic explosion ranging from primary to tertiary, etc. The nanofibers 51 that are efficiently manufactured and generated flow while turning around the axis of the cylindrical container 46 toward the lower side of the cylindrical container 46 at the reflective electrode 49. Further, the nanofiber 51 that has flowed downward while swirling is strongly sucked toward the collection electrode 43 disposed below, and the collection electrode 43 is in a direction opposite to the swirl flow direction of the nanofiber 51. , The nanofibers 51 that are swirling and flowing are more strongly twisted and converged and combined, and a high-strength yarn 55 is efficiently formed. The formed yarn 55 passes through the through hole 52 at the center of the collecting electrode 43 and is collected by the collecting means 45 (see Japanese Patent Application No. 2007-141907).

  However, in the configuration as shown in FIG. 5, the large-area flat plate-like collecting electrode 43 is arranged so as to face the nanofiber generating means 42, and as shown in FIG. The electric lines of force 56 generated between the collecting electrodes 43 are formed so as to spread over the entire surface of the collecting electrode 43, and the nanofibers 51 try to flow along the electric lines of force 56. There is a problem in that the winding position is not constant, the thickness of the generated yarn 55 is not constant, and the thickness of the yarn 55 varies.

  Therefore, the generated nanofiber has a potential difference with respect to the charged nanofiber, has a through hole in the axial center, and has a maximum outer diameter of 1/10 or less of the distance from the spinning head. Electric force that is twisted by swirling and concentrating while sucking in, collecting the twisted nanofibers through the through hole of the collecting electrode, and converging from the spinning head to the circumference of the axial center of the collecting electrode A stable line is formed, and all the nanofibers that swirl and flow are caused to flow along the lines of electric force to be stably focused on the axial center of the collecting electrode, so that there is no variation in thickness. A method has been proposed in which stable yarns are combined with good productivity at low cost (see Japanese Patent Application No. 2007-234762).

  However, even in such a spinning method, the plurality of small holes through which the raw material liquid of the spinning head flows out do not face the collecting electrode, and nanofibers are generated between them by electrostatic explosion. Since it is necessary to take a relatively large distance, the electric charge is not sufficiently induced in the small hole, so that the electric charge cannot be sufficiently charged in the raw material liquid, and the production of nanofibers cannot be secured stably. There was a problem. Further, in order to solve this problem, when the high voltage of opposite polarity is applied to each of the spinning head and the collecting electrode, the insulation structure of the rotating container constituting the spinning head becomes complicated and There is a problem that it is difficult to prevent leakage of high voltage to the rotating mechanism. In addition, when the raw material liquid is caused to flow out of the small hole of the rotating container by centrifugal force, the raw material liquid spreads in an unstable manner without being restricted by the centrifugal force. In addition, there is a problem that the uniform yarn-binding action at the collecting electrode is not stable.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and is capable of stably producing a high-strength and homogeneous yarn composed of nanofibers produced by a charge-induced spinning method with high productivity and low cost. It is an object of the present invention to provide a fiber knitting method and apparatus.

  The nanofiber compounding method according to the present invention includes a step of supplying a core yarn, a raw material solution in which a polymer substance is dissolved in a solvent is discharged from a small hole disposed around the core yarn, and the nanofiber is disposed around the small hole. Raw material liquid outflow charging process that generates an electric field between the electrode and the small hole to charge the raw material liquid flowing out from the small hole, and the nanofiber generated by electrostatic explosion of the raw material liquid flowing out from the small hole moves the core yarn It has a nanofiber swirl flow process that swirls and flows toward a collecting electrode arranged in a direction or in a direction opposite to that, and a recovery process that collects the yarn in which the nanofiber is entangled with the core yarn.

  The raw material liquid includes various synthetic resin materials, and high-molecular substances such as biopolymers such as nucleic acids and proteins (in the present invention, not only general high-molecular substances having a molecular weight of 10,000 or more, but a molecular weight of 1000 to A solution in which a quasi-polymer substance of 10,000 is also dissolved in a solvent is preferably applied. The polymer substance is not limited to a single substance, and may be a mixture of various polymer substances.

  According to the above configuration, since the small hole and the electrode are substantially opposed to each other, and it is not necessary to take a large distance necessary for generating the nanofibers between them, the small hole and the electrode are extremely small. Even if a high voltage is not applied to them, a sufficiently high electric field can be generated between them to reliably induce sufficient charges in the small holes, and the flowing out raw material liquid can be sufficiently charged. Electrostatic explosion is surely generated in the outflowing raw material liquid, and nanofibers are generated. The generated nanofibers are swirled toward the collecting electrode, so that they are entangled with the core yarn, and the core yarn is entangled with the nanofiber. By collecting the strands, high-strength and homogeneous yarns can be stably combined, and high-strength and homogeneous yarns composed of nanofibers can be produced with high productivity and at low cost. .

  In the raw material liquid outflow charging step, the raw material liquid is flowed out by centrifugal force by rotating a small hole around the core yarn, and when the generated nanofiber is swung around the core yarn, the charged material is charged Not only does the liquid flow out toward the electrode by the action of an electric field, but it also flows out by the action of centrifugal force, so that the raw material liquid that has flowed linearly from the small hole can be stretched even by centrifugal force, making it more efficient A fiber can be produced, and the nanofiber is strongly swirled and flowed by the rotation of the small hole, so that the core yarn is strongly twisted and entangled, and a higher strength yarn can be manufactured.

  Further, in the nanofiber swirling flow process, the swirling gas flow that blows the gas flow swirling from the small hole side toward the collecting electrode side, sucks the gas flow near the collecting electrode, and focuses near the formed collecting electrode. When the nanofibers generated in step 1 are entangled with the core yarn, the generated nanofibers swirl on the swirling gas flow, and the swirling gas flow is sucked in the vicinity of the collecting electrode, so that the swirling radius Since the diameter becomes smaller and the swirl flow becomes stronger, the nanofiber is twisted more strongly and entangled with the core yarn, so that a higher-strength yarn can be manufactured. In this case, the nanofibers can be swirled and entangled with the core yarn without rotating the small hole around the core yarn and the collecting electrode not rotating about its axis. By using the rotation around the core yarn of the small hole and the rotation around the core yarn of the collecting electrode, a higher-strength yarn can be manufactured.

  Also, in the nanofiber swirl flow process, if the nanofiber generated in the wind tunnel surrounding the core yarn is entangled with the core yarn, the swirl range of the nanofiber that is generated and swirled is surely regulated by the wind tunnel. Thus, the nanofiber can be stably entangled with the core yarn, and the yarn can be manufactured stably. In addition, the configuration in which the wind tunnel is provided is particularly effective when a swirling gas flow that converges in the vicinity of the collecting electrode is formed by blowing and sucking the swirling gas flow in the vicinity of the collecting electrode as described above. It is.

  Further, in the nanofiber swirl flow process, when the core yarn is moved through the through hole formed in the axial center portion of the collecting electrode and the generated nanofiber is focused near the through hole of the collecting electrode, the nanofiber becomes the collecting electrode. It is possible to reliably entangle the core yarn in the vicinity of the shaft center and to collect the yarn thus produced as it is through the through hole.

  The nanofiber combination device of the present invention includes a core yarn supplying means for moving a core yarn along a predetermined path, and a raw material obtained by dissolving a polymer substance in a solvent from a plurality of small holes arranged around the predetermined path. A spinning head for flowing the liquid, an electrode arranged around the spinning head, an electric field generating means for generating an electric field between the spinning head and the electrode and charging the raw material liquid flowing out from the small hole, and the core yarn passes therethrough. A collecting electrode that has a through-hole and that is applied with a voltage of the opposite polarity to the charged charge of the raw material liquid or is grounded, and a nanofiber generated by electrostatic explosion of the raw material liquid that has flowed out of the small hole toward the collecting electrode It comprises nanofiber swirl flow means for causing the nanofibers to entangle with the core yarn while flowing while swirling, and recovery means for collecting the yarn in which the nanofibers are entangled with the core yarn.

  According to this configuration, it is possible to stably combine high-strength and homogeneous yarns by carrying out the above-mentioned nanofiber spinning method, and to produce high-strength and homogeneous yarns composed of nanofibers with low productivity. It can be manufactured at cost.

  In addition, the spinning head has a through-hole through which a predetermined path passes in the shaft center part, a rotating container having a plurality of small holes on the peripheral surface, a rotation driving means for rotating the rotating container around the axis, And a raw material liquid supply means for supplying the raw material liquid to the substrate, it is possible to cause the raw material liquid to flow out from the small hole on the peripheral surface by centrifugal force by rotating the rotating container with the rotation driving means, and from the small hole to the linear shape The raw material liquid that has flowed out of the core can be stretched even by centrifugal force, so that nanofibers can be generated more efficiently, and the nanofibers are strongly swirled by the rotation of the small holes, so that the core yarn is strongly twisted and entangled, Higher strength yarn can be produced.

  In addition, when the nanofiber swirling flow means has a rotating means for rotating around one or both of the spinning head and the collecting electrode around a predetermined path, the electric field between the spinning head and the collecting electrode is swung to be charged. The nanofiber can be swirled and reliably entangled with the core yarn that moves along a predetermined path.

  Also, the nanofiber swirl flow means has both a spinning head and a collecting electrode having respective rotating means. When both rotating means rotate in the same direction or in the opposite direction around a predetermined path, both the spinning head and the collecting electrode rotate. By doing so, it is possible to produce a yarn having a desired property by adjusting the entanglement of the produced nanofibers with respect to the core yarn.

  In addition, when the nanofiber swirling flow means has a blowing means for generating a gas flow that flows from the spinning head side toward the collection electrode side, the generated nanofibers are placed on the gas flow to the collection electrode side. It is possible to smoothly and surely deflect and flow toward.

  Further, when the nanofiber swirling flow means has swirling air flow blowing means for generating a swirling gas flow that swirls and flows from the spinning head side toward the collecting electrode side, the generated nanofibers are swirled by the swirling gas flow. Can be swirled and flowed toward the collecting electrode, and a nanofiber can be more strongly entangled with the core yarn to produce a high-strength yarn.

  In addition, if the nanofiber swirl flow means has a wind tunnel surrounding the space between the electrode and the collection electrode, the nanofiber swirl range is reliably regulated by the wind tunnel to stabilize the nanofiber. Thus, the yarn can be entangled with the core yarn and the yarn can be manufactured stably.

  In addition, when the wind tunnel has an opening in the vicinity of the periphery of the collection electrode and a suction means for sucking the gas flow from the opening is provided, the generated nanofiber swirls and flows on the swirling gas flow, Furthermore, since the swirling gas flow is sucked in the vicinity of the collecting electrode, the swirl radius becomes smaller, resulting in a stronger swirling flow, so that the nanofibers are twisted more strongly and entangled with the core yarn, resulting in higher strength Can be manufactured.

  According to the nanofiber spinning method and apparatus of the present invention, since the small hole and the electrode are substantially opposed to each other without providing a large gap, a sufficiently high electric field can be easily generated between them, and sufficient charge is induced in the small hole. The discharged raw material liquid can be sufficiently charged, and the discharged raw material liquid is surely subjected to electrostatic explosion and nanofibers are generated and swirled toward the collecting electrode and entangled with the core yarn. Therefore, by collecting the yarn in which the nanofiber is entangled with the core yarn, it is possible to stably produce a high-strength and homogeneous yarn with high productivity and low cost. Further, in a configuration provided with a wind tunnel, the same effect can be obtained even if a suction means for sucking a gas flow from the through hole of the collecting electrode is provided.

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

(First embodiment)
First, a first embodiment of the nanofiber spinning device of the present invention will be described with reference to FIGS.

  In FIG. 1, reference numeral 1 denotes a nanofiber spinning device, and an electric field is provided between a spinning head 3 that flows out the raw material liquid of the nanofiber 2 in a linear manner and the spinning head 3 around the spinning head 3. An electric field generating electrode 4 for generating the core, a collecting electrode 5 for collecting the generated nanofibers 2, and a core yarn supplying means for supplying the core yarn 6 through a predetermined path passing through the spinning head 3 and the axial center of the collecting electrode 5 7 and a collection means 9 for collecting the yarn 8 generated by entanglement of the nanofiber 2 with the core yarn 6.

  As shown in FIGS. 1 and 2, the spinning head 3 is rotatably supported around a vertical axis, and a large number of small holes 10 having a diameter of about 0.01 to 2 mm are formed on the peripheral surface at intervals of several mm. A rotating container 11 made of a cylindrical container is provided, and the rotating container 11 is rotationally driven in the direction of arrow a by the rotation driving means 12. As the rotation driving means 12, a DC motor disposed through an output shaft composed of a hollow shaft is suitably applied. One end of the rotating container 11 is closed by a closed wall 11a, and a support boss 13 having a large-diameter tapered fitting hole 13a and a small-diameter through hole 13b is provided at the axial center of the inner surface of the closed wall 11a. Yes. A large-diameter mounting portion 15 that is taper-fitted to the taper fitting hole 13a of the support boss 13 is provided at the tip of the output shaft of the rotation driving means 12 or the hollow rotary shaft 14 that is connected to the same axis. Yes. Thus, the rotating container 11 is arranged so as to cover the tip of the hollow rotary shaft 14, and the closing wall 11 a and the mounting portion 15 are attached by the mounting bolt 16 in a state where the taper fitting hole 13 a is fitted to the mounting portion 15. The rotary container 11 is attached to the hollow rotary shaft 14 by fastening and fixing.

  An annular weir 17 is provided on the inner periphery of the other end of the rotating container 11, and a layer of the raw material liquid 20 having a predetermined thickness is formed on the outer periphery of the rotating container 11 by centrifugal force while the rotating container 11 is rotating. Is formed. The raw material liquid 20 stored in the storage container 19 is supplied at a predetermined flow rate into the rotary container 11 by the raw material liquid supply means 18 including the supply pump 18a and the supply pipe 18b, and the raw material supplied excessively. The liquid 20 flows out through the weir 17 and is recovered by the raw material liquid recovery means (not shown) and returned to the storage container 19.

  The raw material liquid 20 is obtained by dissolving a polymer substance in a solvent. Examples of the polymer substance include polypropylene, polyethylene, polystyrene, polyethylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and 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, nylon, aramid, polycaprolactone, polylactic acid, polyglycolic acid, collagen, polyhydroxybutyric acid, poly Vinyl acid, can be exemplified a polypeptide such as a suitable, and even can be exemplified such as biopolymers such as nucleic acids or proteins, at least one selected from these are used, but the invention is not particularly limited thereto.

  Examples of the solvent that can be used include methanol, ethanol, 1-propanol, 2-propanol, hexafluoroisopropanol, tetraethylene glycol, triethylene glycol, dibenzyl alcohol, 1,3-dioxolane, 1,4-dioxane, methyl ethyl ketone, Methyl isobutyl ketone, methyl n-hexyl ketone, methyl n-propyl ketone, diisopropyl ketone, diisobutyl ketone, acetone, hexafluoroacetone, phenol, formic acid, methyl formate, ethyl formate, propyl formate, methyl benzoate, ethyl benzoate , Propyl benzoate, methyl acetate, ethyl acetate, propyl acetate, dimethyl phthalate, diethyl phthalate, dipropyl phthalate, methyl chloride, ethyl chloride, methylene chloride, chloroform, o Chlorotoluene, p-chlorotoluene, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, trichloroethane, dichloropropane, dibromoethane, dibromopropane, methyl bromide, ethyl bromide, propyl bromide, acetic acid, benzene , Toluene, hexane, cyclohexane, cyclohexanone, cyclopentane, o-xylene, p-xylene, m-xylene, acetonitrile, tetrahydrofuran, N, N-dimethylformamide, pyridine, water, etc., and at least one selected from these Although used, it is not particularly limited to these. The mixing ratio of the solvent and the polymer material varies depending on the solvent and the polymer material, but the amount of the solvent is preferably about 60% to 98%.

  The raw material liquid 20 can be mixed with an inorganic solid material in addition to the polymer substance and the solvent. Examples of the inorganic solid material include oxides, carbides, nitrides, borides, silicides, fluorides, sulfides, etc. From the viewpoint of heat resistance and workability, oxides are used. preferable. The oxides include Al2O3, SiO2, TiO2, Li2O, Na2O, MgO, CaO, SrO, BaO, B2O3, P2O5, SnO2, ZrO2, K2O, Cs2O, ZnO, Sb2O3, As2O3, CeO2, V2O3, Cr2O3, Cr2O3, Cr2O3 , CoO, NiO, Y 2 O 3, Lu 2 O 3, Yb 2 O 3, HfO 2, Nb 2 O 5 and the like can be exemplified, and at least one selected from these can be used, but is not particularly limited thereto.

  The electric field generating electrode 4 is arranged in a ring shape with a predetermined interval from the peripheral surface of the rotating container 11 constituting the spinning head 3, and a high potential difference is applied between the rotating container 11 and the electric field generating electrode 4. . In the present embodiment, at least the peripheral surface of the rotating container 11 or the vicinity of the small hole 10 has conductivity and is set to the ground potential, and is generated by the first high voltage generating means 21 with respect to the electric field generating electrode 4. A high voltage of the negative electrode is applied. Thus, an electric field is generated between at least the vicinity of the small hole 10 of the rotating container 11 and the electric field generating electrode 4, and a positive charge is induced in the small hole 10, and the charge is charged to the raw material liquid 20 flowing out from the small hole 10. As the solvent in the raw material liquid 20 evaporates, an electrostatic explosion of the first to third order, or even higher order, occurs and the nanofiber 2 is generated. Note that the first high voltage generating means 21 may apply a positive or negative high voltage to the rotating container 11 to set the electric field generating electrode 4 to the ground potential, but the rotating container 11 connected to the rotation driving means 12 may be used. Since the high voltage is not applied to the peripheral devices such as the rotation driving means 12 connected to the rotating container 11, it is preferable that their insulation configuration is simplified.

  On the upper side of the rotation driving means 12 opposite to the rotating container 11, a blowing means 22 is disposed as a deflection flow means for deflecting and flowing the generated nanofibers 2 toward the collecting electrode 5. The gas flow 23 is blown toward the space between the peripheral surface of the electrode and the electric field generating electrode 4. As the deflecting flow means, a reflective electrode to which a high voltage having the same polarity as the charging polarity of the nanofiber 2 is applied may be provided in place of the air blowing means 23 or in combination with the air blowing means 23. The deflecting flow means is not limited to this, and instead of the air blowing means 22, the nanofiber produced by providing the air blowing means or the suction means below the collecting electrode 5 below the rotating container 11. 2 may be deflected toward the collecting electrode 5.

  The core yarn supply means 7 is disposed further above the air blowing means 22. The core yarn supply means 7 includes a core yarn supply roll 7 a wound around the core yarn 6 so that the core yarn 6 can be fed out, and a guide roller 7 b that guides the fed core yarn 6 so as to be supplied to the axial center position of the rotary container 11. ing. The core yarn 6 fed out from the core yarn supply means 7 has a through hole 22a formed at the axial center position of the blower means 22, the hollow output shaft of the rotation drive means 12, the hollow portion of the hollow rotary shaft 14, and the rotary container. 11 is supplied toward the axial center position of the collection electrode 5 through the through hole 13b of the support boss 13.

  The collecting electrode 5 is arranged in the same axial center as the rotational axis of the rotary container 11 at a position separated from the rotary container 11 of the spinning head 3 by an appropriate distance in the axial direction. The distance between the rotating container 11 and the collecting electrode 5 is that the first to third or higher order electrostatic explosion occurs in the raw material liquid 20 flowing out from the small hole 10 of the rotating container 11 to generate the nanofiber 2. This is the required distance required to As shown in FIGS. 1 and 3, the collecting electrode 5 has a shaft body 24 having a substantially hemispherical enlarged head 24a at one end on the spinning head 3 side and a through hole 24b in the axial center. Has been. The collecting electrode 5 only needs to have conductivity on the outer surface of the enlarged head 24a, and the other portions do not necessarily have conductivity.

  The collecting electrode 5 is connected to the rotation driving means 27 through a hollow shaft joint 26 whose other end portion of the shaft body 24 is supported by a bearing 25 so as to be rotatable around its axis and whose other end is made of an insulating material. Then, the rotary container 11 is rotationally driven in the direction of arrow b opposite to the rotational direction a. As this rotation driving means 27, a DC motor arranged through an output shaft made of a hollow shaft is suitably applied. The yarn 8 in which the nanofibers 2 are converged and combined by the collecting electrode 5 is directed to the collecting means 9 through the through hole 24b of the collecting electrode 5, the hollow shaft joint 26, and the hollow output shaft portion of the rotation driving means 27. Moved and collected.

  At least the enlarged head 24a of the collecting electrode 5 is connected to the second high voltage generating means 28 for generating a positive or negative (negative in the illustrated example) high voltage of 1 kV to 100 kV, preferably 10 kV to 100 kV, and the rotating container. 11, an electric field is generated between at least the vicinity of the small hole 10 and the collecting electrode 5. The fiber deflection path 29 formed by the electric field between at least the small hole 10 of the rotating container 11 and the collecting electrode 5 is formed from the vicinity of the small hole 10 of the rotating container 11 to the electric field generating electrode 4 as shown in FIG. After heading, it is deflected toward the enlarged head 24a of the collecting electrode 5 and converges around the through hole 24b of the enlarged head 24a. Thus, the positive charge charged in the vicinity of the small hole 10 of the rotating container 11 is charged to the raw material liquid 20 flowing out from the small hole 10, and the charged raw material liquid 20 is directed to the electric field generating electrode 4 along the deflection path 29 of the fiber. Then, it is deflected and flows toward the collecting electrode 5, and electrostatic explosion occurs between them to generate the nanofiber 2.

  In the above configuration, the rotary container 11 is rotationally driven while supplying the raw material liquid 20 into the rotary container 11 of the spinning head 3. Then, the raw material liquid 20 in the rotating container 11 is charged with electric charge in each small hole 10, and the raw material liquid 20 is reliably directed toward the electric field generation electrode 4 by the action of the electric field between the electric field generation electrode 4 and the action of centrifugal force. It flows out linearly and is stretched by the action of centrifugal force. Thereafter, the solvent in the raw material liquid 20 flowing out linearly evaporates, and the diameter of the linear body is reduced. As a result, the charged charges are concentrated, and the Coulomb force reduces the surface tension of the raw material liquid 20. When exceeded, a primary electrostatic explosion occurs and the film is stretched explosively.After that, the solvent further evaporates, and similarly a secondary electrostatic explosion occurs and the film is stretched explosively. The nanofiber 2 made of a polymer material having a submicron diameter is efficiently produced by being generated and stretched.

  The nanofiber 2 that is being generated or generated is directed from the outer periphery of the rotating container 11 toward the collecting electrode 5 by the gas flow 23 blown by the blowing means 22, and the axis of the rotating container 11 by the rotation of the rotating container 11. It will flow while turning around. In addition, when the gas flow 23 is made into warm air, since evaporation of a solvent is accelerated | stimulated, the production | generation of the nanofiber 2 can be accelerated | stimulated and it is preferable. The nanofiber 2 that flows while swirling on the gas flow 23 is strongly sucked by the collecting electrode 5, and the collecting electrode 5 rotates in the direction opposite to the swirling flow direction of the nanofiber 2. The nanofibers 2 that are swirling and flowing are more strongly twisted and converged and combined. Here, since the electric lines of force from the rotating container 11 toward the collecting electrode 5 are stably formed so as to converge around the axial center of the collecting electrode 5, the nanofibers 2 that have swirled and flowed Flows along the lines of electric force and is stably focused on the axial center of the collecting electrode 5 and reliably entangled with the core yarn 6 to be focused at once, thus the nanofibers 2 are uniformly twisted. A homogeneous yarn 8 entangled with the core yarn 6 and having no variation in thickness is generated, and the high-strength yarn 8 is stably formed with good productivity. The formed yarn 8 passes through the through hole 24 b of the collecting electrode 5 and is collected by the collecting means 9.

  In the illustrated examples of FIGS. 1 and 2, an example in which the rotating container 11 having the small holes 10 formed on the peripheral surface is applied is shown. However, a large number of short nozzles are provided on the peripheral surface of the rotating container 11 at appropriate pitch intervals. It is good also as a structure which has arrange | positioned a member and made the nozzle hole currently formed in the nozzle member function as the small hole 10. FIG.

  In the present embodiment, an example is shown in which the rotating container 11 of the spinning head 2 is rotated in the direction of arrow a, and the collecting electrode 5 is rotated in the direction of arrow b opposite to the direction a. 2 may rotate only the collecting electrode 5 side without rotating, or conversely, only the spinning head 2 side may rotate without rotating the collecting electrode 5. In this embodiment, the rotation direction of the rotating container 11 and the rotation direction of the collecting electrode 5 are opposite to each other. However, the same effect can be obtained even if the rotation directions are different from each other in the same direction. It is done.

(Second Embodiment)
Next, a second embodiment of the nanofiber spinning device of the present invention will be described with reference to FIG. In the description of this embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only differences are mainly described.

  In this embodiment, the wind tunnel 30 made of an insulating material surrounding the space between the electric field generating electrode 4 and the collecting electrode 5 is disposed. The wind tunnel 30 includes a cylindrical portion 30a extending from a lower edge of the electric field generating electrode 4 to a height position of a lower edge of the enlarged head 24a of the collecting electrode 5, and an end plate 30b that closes a lower end opening thereof. The shaft body 24 of the collecting electrode 5 passes through the shaft center portion of the collecting electrode 5 in a rotatable manner, and a plurality of exhaust ports 31 are annularly disposed around the enlarged head 24 a of the collecting electrode 5. An annular suction header 32 is disposed on the lower surface of the end plate 30 b so that the plurality of exhaust ports 31 face each other. The suction header 32 is connected to a suction fan 33 via a suction pipe 34.

  According to the configuration of the present embodiment, when the generated nanofibers 2 swirl on the gas flow 23, the swirl range is reliably regulated by the wind tunnel 30, so that the nanofibers 2 can be reliably cored. The yarn 8 can be entangled with the yarn 6 and the yarn 8 can be manufactured more stably. In particular, the wind tunnel 30 of the present embodiment has the exhaust port 31 in the vicinity of the periphery of the collecting electrode 5, and the gas flow 23 is sucked by the suction fan 33 through the exhaust port 31, so that it is generated. The nanofibers 2 swirl on the gas flow 23, and the gas flow 23 is sucked in the vicinity of the collecting electrode 5, so that the swirl radius is reduced and the nanofibers 2 are twisted more strongly. Thus, the yarn 8 entangled with the core yarn 6 and having higher strength can be manufactured.

  Further, in the above description, the air blowing means 22 has been described as air blowing substantially parallel to the axial direction of the spinning head 3, but the air blowing means 22 is swung from the spinning head 3 side toward the collecting electrode 5 side to flow. In this case, the generated nanofiber 2 can be placed on the swirling gas flow and swirled toward the collecting electrode 5, and the swirling gas flow Since the swirl radius of the swirling gas flow is reduced by being sucked through the exhaust port 31 at a position in the vicinity of the periphery of the collecting electrode 5, the swirling gas flow is swirled and flows. The nanofiber 2 can be more strongly entangled with the core yarn 6 to produce a yarn 8 having high strength. Accordingly, in the case where the wind tunnel 30 is provided in this way and the swirling gas flow is blown by the blowing means 22 and sucked at a position near the periphery of the collecting electrode 5, either the spinning head 3 or the collecting electrode 5 is used. Alternatively, in both cases, the yarn 8 can be manufactured by entwining the nanofiber 2 with the core yarn 6 without rotating.

  In the above embodiment, the spinning head 3 is grounded, and a high voltage is applied to the electric field generating electrode 4 and the collecting electrode 5 so as to be between the spinning head 3 and the electric field generating electrode 4 and between the spinning head 3 and the collecting electrode 5. Although an example in which an electric field is generated between them is shown, a high voltage is applied to the spinning head 3 to bring the electric field generating electrode 4 and the collecting electrode 5 to the ground potential, or the spinning head 3 and the electric field generating electrode 4 and the collecting electrode 5 may be applied with high voltages having opposite polarities or the same polarity. In short, a high potential difference is applied between the spinning head 3 and the electric field generating electrode 4 or the collecting electrode 5 to generate an electric field therebetween. What is necessary is just to comprise so.

  In the second embodiment, the gas flow 23 is sucked through the exhaust port 31. However, the present invention is not limited to this, and suction may be performed from the through hole 24 b of the collecting electrode 5. Further, when the through hole 24b is large enough to stably suck the gas flow 23, the gas flow 23 may be sucked only from the through hole 24b of the collecting electrode 5 instead of the exhaust port 31. Good.

  According to the nanofiber spinning method and apparatus of the present invention, since the small hole and the electrode are substantially opposed to each other, a sufficiently high electric field can be easily generated between them, and the raw material liquid that is sufficiently induced in the small hole and flows out. Can be sufficiently charged, and an electrostatic explosion occurs reliably in the raw material liquid that has flowed out, and nanofibers are generated and swirled toward the collection electrode and entangled with the core yarn. By collecting the entangled core yarn, a high-strength and homogeneous yarn can be manufactured stably and with good productivity at low cost, making it suitable for producing high-strength yarn made of nanofibers. Can be used.

The partial cross section front view which shows the whole schematic structure of the nanofiber synthesizing | combining apparatus in the 1st Embodiment of this invention. Explanatory drawing which shows the generation | occurrence | production state of the deflection | deviation path | route of the fiber between the spinning head and the collection electrode in the embodiment. Sectional drawing which shows the structure of the spinning head in the embodiment. The perspective view which shows the whole schematic structure of the nanofiber spinning device in the 2nd Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an overall schematic configuration of a nanofiber spinning device that precedes the present invention. Explanatory drawing which shows the generation | occurrence | production state of the electric force line | wire between the spinning head and the collection electrode in the nanofiber spinning device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nanofiber spinning device 2 Nanofiber 3 Spinning head 4 Electric field generating electrode 5 Collection electrode 6 Core yarn 7 Core yarn supply means 8 Thread 9 Collection means 10 Small hole 11 Rotating container 12 Rotation drive means 18 Raw material liquid supply means 20 Raw material liquid 21 1st high voltage generation means (electric field generation means)
22 Blowing means 23 Gas flow 24b Through-hole 27 Rotation driving means 28 Second high voltage generating means 30 Wind tunnel 31 Exhaust port 33 Suction fan

Claims (14)

Supplying a core yarn;
A raw material solution in which a polymer substance is dissolved in a solvent is caused to flow out from a small hole arranged around the core yarn, and an electric field is generated between the electrode arranged around the small hole and the small hole, and flows out from the small hole. A raw material liquid outflow charging step of charging the raw material liquid
A nanofiber swirl flow step of swirling nanofibers generated by electrostatic explosion of the raw material liquid flowing out from the small holes toward a collecting electrode arranged in a predetermined position in the direction of movement of the core yarn or in the opposite direction thereof;
And a recovery step of recovering the yarn in which the nanofiber is entangled with the core yarn.   In the raw material liquid outflow charging step, by rotating the small hole around the core yarn, the raw material liquid is caused to flow out by centrifugal force, and the generated nanofibers are turned around the core yarn. Item 2. A method for combining nanofibers according to Item 1.   In the nanofiber swirling flow step, a gas flow swirling from the small hole side toward the collecting electrode side is blown, a gas flow is sucked near the collecting electrode, and focused near the formed collecting electrode. 3. The nanofiber synthesizing method according to claim 1, wherein the nanofiber generated by the swirling gas flow is entangled with the core yarn.   The nanofiber according to any one of claims 1 to 3, wherein in the nanofiber swirl flow step, the nanofiber generated in a wind tunnel surrounding the core yarn is entangled with the core yarn. Synthetic yarn method.   The nanofiber swirl flow step, wherein the core yarn is moved through a through hole formed in an axial center portion of the collection electrode, and the generated nanofiber is focused near the through hole of the collection electrode. The method for synthesizing nanofibers according to any one of 1 to 4. A core yarn supplying means for moving the core yarn along a predetermined path;
A spinning head for flowing out a raw material solution obtained by dissolving a polymer substance in a solvent from a plurality of small holes arranged around the predetermined path;
Electrodes arranged around the spinning head;
An electric field generating means for generating an electric field between the spinning head and the electrode to charge the raw material liquid flowing out of the small hole;
A collecting electrode having a through hole through which the core yarn passes and to which a voltage having a polarity opposite to the charged charge of the raw material liquid is applied or grounded;
Nanofiber swirling flow means for causing nanofibers generated by electrostatic explosion of the raw material liquid flowing out from the small holes to flow while swirling toward the collecting electrode, and entangle the nanofibers with the core yarn,
A nanofiber synthesizing apparatus comprising: a collecting means for collecting the yarn in which the nanofiber is entangled with the core yarn.   The spinning head has a through-hole through which a predetermined path passes in an axial center portion, a rotating container having a plurality of small holes on a peripheral surface, a rotation driving means for rotating the rotating container around the axis, and the rotating container 7. The nanofiber spinning device according to claim 6, further comprising a raw material liquid supply means for supplying the raw material liquid therein.   The nanofiber spinning yarn according to claim 6 or 7, wherein the nanofiber swirl flow means has a rotating means for rotating one or both of the spinning head and the collecting electrode around a predetermined path. apparatus.   7. The nanofiber swirl flow means has both the spinning head and the collecting electrode each having a rotating means, and both rotating means rotate in the same direction or in the opposite direction around a predetermined path. Or a nanofiber synthesizing device according to 7;   The nanofiber swirl flow means has a blower means for generating a gas flow that flows from the spinning head side toward the collecting electrode side, according to any one of claims 6 to 9. The nanofiber synthesizing apparatus as described.   The nanofiber swirl flow means has swirl airflow blowing means for generating a swirl gas flow swirling and flowing from the spinning head side toward the collecting electrode side. The nanofiber spinning device according to any one of the above.   The nanofiber spinning device according to claim 10 or 11, wherein the nanofiber swirl flow means includes a wind tunnel surrounding a space between the electrode and the collection electrode.   13. The nanofiber spinning device according to claim 12, wherein the wind tunnel has an opening in the vicinity of the periphery of the collecting electrode, and is provided with suction means for sucking a gas flow from the opening.   13. The nanofiber spinning device according to claim 12, wherein the wind tunnel is provided with suction means for sucking a gas flow from a through hole of the collecting electrode.

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