JP4897579B2 - Nanofiber manufacturing apparatus, non-woven fabric manufacturing apparatus, and nanofiber manufacturing method - Google Patents

Description

  The present invention relates to an apparatus and a method for producing a nanofiber made of a polymer material. Moreover, it is related with the manufacturing apparatus of the nonwoven fabric comprised with a nanofiber.

  An electrospinning method is known as a method for producing a filamentous material (hereinafter referred to as “nanofiber”) made of a polymer material and having a submicron-scale diameter.

  This electrospinning method is a method in which a polymer solution in which a polymer substance is dispersed in a solvent is ejected (outflowed) from a needle-like nozzle to which a high voltage is applied to a collector (collecting electrode) toward the collector. This is a method for obtaining a nanofiber.

  More specifically, the charged polymer solution is injected into the space by setting the injection nozzle to a high voltage, and the charge density of the polymer solution flying in the space increases as the solvent evaporates. A phenomenon (electrostatic explosion) in which the polymer solution is explosively stretched linearly occurs when the repulsive Coulomb force generated in the polymer solution exceeds the surface tension of the polymer solution. This electrostatic explosion occurs one after another in the space, so that nanofibers made of a polymer having a submicron diameter are manufactured.

  In addition, by depositing nanofibers manufactured by the above-mentioned method on a substrate, a three-dimensional thin film having a three-dimensional network can be obtained, and by forming a thicker film, a high thickness having a submicron network can be obtained. A porous web (nonwoven fabric) can be produced.

  The web produced by employing the electrospinning method as described above is highly porous composed of nano-order pores and has a large surface area as a whole, so that it is a filter, battery separator, or fuel cell polymer electrolyte membrane. It is expected to obtain a high effect when applied to electrodes and electrodes.

  Conventionally, as a method for producing a large amount of nanofibers to produce a practical web made of nanofibers, an apparatus for producing a web by arranging a plurality of nozzles in parallel and depositing a large amount of nanofibers has been proposed. (For example, refer to Patent Document 1).

The apparatus applies a high voltage of 5 KV or more between the nozzle and the collector, and grounds the collector or applies a voltage having a polarity opposite to that of the nozzle to manufacture the nanofiber.
JP 2002-201559 A

  In the conventional nanofiber manufacturing apparatus, as described in Patent Document 1, a high DC voltage (for example, 5 KV or more) is applied to the nozzle. On the other hand, various devices and members such as a pipe for supplying the raw material of the nanofiber, a tank for storing the raw material, and a pump for pumping the raw material to the nozzle are attached to the nozzle.

  Therefore, in order to maintain the nozzle at a high voltage, a high-voltage insulation is provided between members and devices existing around the nozzle, and the entire nozzle that is at a high voltage is enclosed and covered for safety reasons. Measures such as are taken.

  However, these various insulated members are charged to a high voltage, and abnormal discharge such as corona discharge occurs from these members, or ion wind is generated, affecting the human body, Problems such as adverse effects on manufacturing have occurred.

  For example, dust and debris charged at a high voltage generated by the ion wind adhere to peripheral devices, destroying components and semiconductor elements used in the peripheral devices, and making the device unusable. In some cases. Further, when a high voltage is applied to the tip of the nozzle, electric lines of force are generated from the nozzle toward a booth that covers the nanofiber manufacturing apparatus, and the generated charged dust or dirt is generated. Move to the booth along the lines of electric force and attach to the booth. In this way, charged dust and debris attached to peripheral devices and incidental equipment maintain a high voltage, and have a great influence on the nanofiber itself charged to the same polarity generated from the nozzle. It will lead to hindrance to collection and decrease in collection rate.

  In particular, when a flammable substance is used as a raw material for the nanofiber, there is a risk of ignition or explosion due to abnormal discharge from the member.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a nanofiber manufacturing apparatus and the like that can prevent charging of members such as nozzles in the vicinity of injection means.

  In order to achieve the above object, a nanofiber manufacturing apparatus according to the present invention includes an injection means having an injection hole for injecting a raw material liquid for producing nanofibers, and a collection for collecting and manufacturing nanofibers injected from the injection hole. A nanofiber manufacturing apparatus comprising an electrode, wherein a first power source that applies a voltage selected from a range of 10 KV or more and 200 KV or less between the collection electrode and the jetting unit, and 5 V or more and 1000 V to the jetting unit And an AC power supply for applying an AC voltage selected from the following range in a superimposed manner. The first power supply applies a potential selected from the range of −200 KV or more and −10 KV or less, or +10 KV or more and +200 KV or less to the collecting electrode, and the AC power supply supplies the ejection unit with 5 V or more and 1000 V. It is preferable to apply an alternating voltage selected from the following range.

  As a result, since the AC voltage is applied to the ejecting means, charging of the members existing in the vicinity of the ejecting means can be suppressed, and abnormal discharge and ion wind generated from these members can be prevented. Nanofibers can be manufactured safely.

  Moreover, if it is a nonwoven fabric manufacturing apparatus provided with the said nanofiber manufacturing apparatus, it will become possible to manufacture the nonwoven fabric which consists of high quality nanofiber, enjoying the said effect | action and effect.

  According to the present invention, it is possible to provide a nanofiber manufacturing apparatus that can stabilize the productivity of nanofibers and ensure high safety.

  Next, an embodiment of a nonwoven fabric manufacturing apparatus including the nanofiber manufacturing apparatus according to the present invention will be described.

FIG. 1 is a perspective view schematically showing a non-woven fabric manufacturing apparatus according to the present invention.
As shown in the figure, the nonwoven fabric manufacturing apparatus 100 includes a nanofiber manufacturing apparatus 180 composed of an injection unit 110 and a collecting electrode 120, and a sheet 160 as a deposition target. In addition, since the raw material liquid to be injected and the nanofiber being manufactured cannot be clearly distinguished, the reference numeral 200 is assigned to each, and the manufactured nonwoven fabric is assigned 210.

  The injection means 110 is an apparatus having an injection hole for injecting (outflowing) a raw material liquid for producing nanofibers. The injection means 110 is connected to the earth 101 via the grounding means 102 or via the second power supply 151. Connected to ground 101. Further, in either case, the AC power supply 190 is connected and the AC voltage is superimposed.

  In the figure, it is described that the connection to the second power supply 151 or the connection to the ground can be selected, but the present invention is not particularly limited to this. A pipe 111 connected to a tank (not shown) for storing the raw material liquid is connected to the injection means 110 so that the raw material liquid is supplied at a predetermined pressure.

  The collection electrode 120 is connected to a power source 150 as a first power source so that a predetermined voltage is applied to the ejection unit 110 and is a device for collecting the manufactured nanofibers 200.

  The power source 150 generates a voltage between the ground 101 and the collecting electrode 120. When the ejecting unit 110 is directly connected to the ground 101, a predetermined voltage is applied to the ejecting unit 110. Will be applied.

  The sheet 160 is a member on which the nanofibers 200 manufactured in the space are to be deposited, and is a thin and flexible long sheet made of a material that can be easily separated from the deposited nanofibers 200. . The sheet 160 is supplied in a state of being wound in a roll shape, and slowly moves in the direction of the arrow in the drawing by the moving means 170 through the portion where the nanofibers 200 are deposited. And it rolls around with the nonwoven fabric 210 manufactured on the sheet | seat 160 again in roll shape.

  The moving means 170 is a device capable of feeding the sheet 160 in one direction while maintaining a predetermined tension, and moves the sheet 160 by rotating a roller shown in the drawing by driving a motor (not shown) or the like. Is.

  The AC power supply 190 is connected between the ground 101 and the ejection unit 110 and is a power supply capable of applying an AC voltage having an amplitude selected from a range of 5 V or more and 1000 V or less with the ground potential as a center.

FIG. 2 is a diagram illustrating a specific example of the ejection unit and the collection electrode.
FIG. 3 is a cross-sectional view showing the rotary cylinder.

  Note that FIG. 2 shows the ejection means 110 larger in order to show the relationship between the ejection means 110 and the collection electrode 120, but in reality, the diameter of the collection electrode 120 is several meters, The diameter of the rotary cylinder 116 is about several centimeters to several tens of centimeters.

  The collecting electrode 120 has a cylindrical shape and can rotate with the movement of the sheet 160 or synchronously. The collecting electrode 120 has a rounded chamfer at the cylindrical edge portion so that the diameter gradually decreases toward the end surface of the collecting electrode 120.

  In this way, by making the peripheral edge of the collecting electrode 120 desired from the ejecting means 110 a curved surface that moves away from the ejecting means 110, the disturbance of the electric field due to the edge of the collecting electrode 120 is suppressed, and the deposition state of the nanofiber 200 is improved. It can be.

  As shown in FIG. 2, the injection means 110 is a device that injects (flows out) the raw material liquid by centrifugal force, and serves as a rotary shaft that also serves as the rotary cylinder 116 and the pipe 111 for supplying the raw material liquid 200. A shaft 117, a motor 118, a base body 119, a belt 115, and a pulley 114 are provided.

  The rotary cylinder 116 is radially provided with a plurality of nozzles 113 each having an injection hole 112 on a cylindrical peripheral wall sealed at one end. A shaft 117 is attached to the central portion of the other end of the rotary cylinder 116. The rotary cylinder 116 is rotatably attached to the base body 119 via a shaft 117.

  The motor 118 and the pulley 114 fixed to the shaft 117 are connected by a belt 115, and the motor 118 is attached to the base 119. By rotating the motor 118, the rotary cylinder 116 can be rotated relative to the base body 119.

  Further, as shown in FIG. 3, the shaft 117 and the other end of the rotary cylinder 116 are connected so that liquid can be inserted. Further, both the shaft 117 and the rotary cylinder 116 are made of a conductor.

  The rotary cylinder 116 and the AC power source 190 are connected via a shaft 117 using a brush 203. Since the brush 203 is used, an alternating voltage can be applied even when the rotary cylinder 116 is in a rotating state.

  The rotary cylinder 116 is connected via a shaft 117 to a tank 202 in which the raw material liquid 200 is stored. A pump 201 is attached on the flow path of the raw material liquid 200 so that the raw material liquid 200 can be pumped toward the rotary cylinder 116.

  Next, a manufacturing method of the nanofiber 200 by the nanofiber manufacturing apparatus 180 configured by the ejection unit 110 and the collecting electrode 120 and a manufacturing method of the nonwoven fabric in which the manufactured nanofiber 200 is deposited to manufacture the nonwoven fabric will be described. .

  First, the raw material liquid 200 is pumped from the tank 202 of the raw material liquid 200 toward the rotary cylinder 116. In the case of the present embodiment, since the raw material liquid 200 is not injected by the pressure, the pressure of pressure feeding is relatively low.

  The raw material liquid 200 is injected into the rotary cylinder 116 through the shaft 117 (pipe 111). The rotary cylinder 116 is rotated by a motor 118, and the injected raw material liquid 200 also generates a centrifugal force due to the rotation. Then, the raw material liquid 200 is radially ejected to the outside of the rotary cylinder 116 by centrifugal force through holes formed in the peripheral wall of the rotary cylinder 116.

  Since the raw material liquid 200 is injected from the rotating injection holes 112, even if there is some variation in the shape of each injection hole 112, the raw material liquid 200 is injected in an equal amount when the entire space is combined. If the injection means 110 as described above is employed, a relatively large amount of nanofibers 200 can be manufactured at once and homogeneously, and the nonwoven fabric 210 in which the manufactured nanofibers are evenly distributed can be manufactured. It becomes possible.

  On the other hand, a voltage selected from the range of +10 KV or higher and +200 KV or lower, or −10 KV or lower and −200 KV or higher is applied to the collecting electrode 120 by the power supply 150. Inductive charges corresponding to the voltage of the collection electrode are generated in the rotary cylinder 116 disposed opposite to the collection electrode 120 so as to be superimposed on the AC voltage, and an electric field is generated between the rotary cylinder 116 and the collection electrode 120. (Electric field lines) are generated.

  In the above state, since the raw material liquid 200 is injected from the rotary cylinder 116, the raw material liquid 200 is given an electric charge necessary for electrostatic explosion and is also supplied along the electric field (electric lines of force). The nanofibers 200 are manufactured by repeating electrostatic explosions.

  Since the manufactured nanofiber 200 is deposited on the sheet 160 and the sheet 160 gradually moves, a long nonwoven fabric is manufactured on the sheet 160.

  As described above, the motor 118, the base 119, the pipe 111 constituting the path for supplying the raw material liquid 200, the raw material liquid tank 202, the pump 201, and the like have an AC voltage with an amplitude of 5 V or more and 1000 V or less around the ground potential. Since it is given, it becomes possible to prevent the member arranged in the vicinity of the ejection unit 110 from being charged. Therefore, abnormal discharge generated from these members can be suppressed as much as possible, safety is high, and the quality of the manufactured nanofiber can be stabilized.

  Further, it is not necessary to provide a high degree of insulation for maintaining the injection unit 110 itself at a high voltage. Therefore, as in the present embodiment, the injection unit 110 can simply include a mechanism for injecting the raw material liquid 200 by rotation. Moreover, it is not necessary to attach the motor 118 and the sensor connected to the tank of the raw material liquid 200 in an insulated state. Therefore, the entire configuration of the ejection unit 110 can be simplified. In other words, the injection means 110 having a simple structure can easily obtain high durability and reliability, and has a high degree of freedom in design. Moreover, it can contribute to reduction of manufacturing cost and maintenance cost.

  Examples of polymer materials for producing nanofibers include polypropylene, polyethylene, polystyrene, polyethylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, poly-m-phenylene terephthalate, poly-p-phenylene isophthalate, polyvinylidene fluoride, Polyvinylidene fluoride-hexafluoropropylene copolymer, polyvinyl chloride, polyvinylidene chloride-acrylate copolymer, polyacrylonitrile, polyacrylonitrile-methacrylate copolymer, polycarbonate, polyarylate, polyester carbonate, nylon, aramid, polycaprolactone, Examples include polylactic acid, polyglycolic acid, collagen, polyhydroxybutyric acid, polyvinyl acetate, and polypeptide. . Further, the polymer material used for the nanofiber production is not limited to one type, and any plurality of types may be selected from the exemplified polymer materials.

  Moreover, as a solvent used in order to manufacture the raw material liquid, methanol, ethanol, 1-propanol, 2-propanol, hexafluoroisopropanol, tetraethylene glycol, triethylene glycol, dibenzyl alcohol, 1,3-dioxolane, , 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, methyl chloride , Chloroform, o-chlorotoluene, p-chlorotoluene, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, trichloroethane, dichloropropane, dibromoethane, dibromopropane, methyl bromide, ethyl bromide, odor Propyl chloride, acetic acid, benzene, toluene, hexane, cyclohexane, cyclohexanone, cyclopentane, o-xylene, p-xylene, m-xylene, acetonitrile, tetrahydrofuran, N, N-dimethylformamide, pyridine, water, etc. it can. Moreover, the solvent used for the nanofiber production is not limited to one type, and any plurality of types may be selected from the above exemplified solvents and mixed and used.

  Moreover, you may mix an inorganic solid material in a raw material liquid. These inorganic solid materials function as an aggregate of the nanofiber to be manufactured, or function as a catalyst or the like supported on the nanofiber. Examples of the inorganic solid material include oxides, carbides, nitrides, borides, silicides, fluorides, and sulfides. Moreover, it is preferable to use an oxide from the viewpoints of heat resistance, workability, and the like.

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 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.

  Further, the resin material forming the nanofibers may be not only the above-mentioned polymer substance but also a low-molecular substance. Even in the case of a low molecular weight substance, the content of the raw material liquid is not different from that of the high molecular weight substance. In this case, the nanofibers are not in a continuous state for a long time, but are produced in the form of fine particles. As an application example of such fine-particle nanofibers, there can be considered a case where a pigment of an organic EL or a liquid crystal color filter is dissolved in a solvent to refine the pigment itself.

  In the present embodiment, an AC voltage based on the ground potential is applied to the ejection unit 110, but it is not necessary to use the ground potential as a reference. For example, a voltage selected from a range of 10 KV or more and 200 KV or less is applied between the ejection unit 110 and the collecting electrode 120 and an AC voltage selected from a range of 5 V or more and 1000 V or less is superimposed on the ejection unit 110. What is applied may be used. For example, the second power source 151 may be connected to the ejection unit 110, a voltage may be applied in the range of −1 KV to +1 KV, and an AC voltage of 5 V or more and 1000 V or less may be applied in a superimposed manner. Although the relationship with the ground potential is not particularly limited, the effect of applying the AC voltage can be stably exhibited by applying a relatively low voltage to the ejection unit 110.

  Note that the ejection unit 110 is not limited to the structure described in the above embodiment. For example, as shown in FIGS. 4A and 4B, a rotary cylinder that rotates on an axis parallel to the collection electrode 120 may be provided. The rotary cylinder 116 shown in the figure is connected to a second power source 151 and an AC power source 190, and a voltage is applied in the range of -1KV to + 1KV and an AC voltage of 5V to 1000V is applied in a superimposed manner. Is done. Alternatively, the setting of the second power supply 151 may be set to 0 V, and only the AC voltage with respect to the ground potential may be applied to the rotary cylinder 116.

  Further, as shown in FIG. 5, the nozzle 113 may be fixedly disposed with respect to the collecting electrode 120. In this case, by disposing the plurality of nozzles 113 obliquely with respect to the moving direction of the sheet 160, the interval between the nozzles 113 can be widened, and the nanofibers 200 are uniformly deposited on the sheet 160. Is possible.

  Further, the collecting electrode 120 is not limited to the structure described in the above embodiment. The collecting electrode 120 may be a simple flat plate shown in FIG. 4, or may be a member having a shape with a rounded edge as shown in FIG.

  In FIG. 1 and FIG. 2, the ejection unit 110 is fixed, but a moving unit is provided to periodically or in a predetermined operation pattern in a direction substantially perpendicular to the moving direction of the sheet 160. It may be moved. By doing so, even if the width of the sheet 160 is increased, the nanofibers 200 can be deposited over the entire width on the sheet 160.

  Further, as described above, even when the ejecting means 110 is moved using a motor or the like, it is not necessary to provide high-level insulation to these moving mechanisms and electronic parts for controlling the moving mechanism. It is possible to avoid the destruction of electronic parts and semiconductors used for the above.

  In FIGS. 1 and 2, only one injection unit 110 is shown. However, if a plurality of the injection units 110 are arranged side by side, when the width of the sheet 160 is increased or the thickness to be deposited is increased. Is an effective means.

  The present invention can be used for manufacturing nanofibers, and in particular, can be used for manufacturing spinning and nonwoven fabrics using nanofibers.

It is a perspective view showing roughly the nonwoven fabric manufacturing device concerning the present invention. It is a figure which shows the specific example of an injection means and a collection electrode. It is sectional drawing which shows a rotary cylinder. It is a figure which shows the other aspect of an injection means and a collection electrode, (a) is a perspective view, (b) is sectional drawing. It is a perspective view which shows the other aspect of an injection means and a collection electrode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Nonwoven fabric manufacturing apparatus 101 Ground 102 Grounding means 110 Injection means 111 Pipe 112 Injection hole 113 Nozzle 114 Pulley 115 Belt 116 Rotary cylinder 117 Shaft 118 Motor 119 Base 120 Collection electrode 150 Power supply 151 Second power supply 160 Sheet 170 Moving means 180 Nanofiber production Device 190 AC power source 200 Nanofiber, raw material liquid 201 Pump 202 Tank 203 Brush 210 Nonwoven fabric

Claims (5)

A nanofiber manufacturing apparatus comprising: an injection means having an injection hole for injecting a raw material liquid for producing nanofibers; and a collecting electrode for collecting nanofibers injected and manufactured from the injection holes,
A first power source for applying a voltage selected from a range of 10 KV or more and 200 KV or less between the collecting electrode and the ejection unit;
Nanofiber production apparatus comprising an AC power source for signs pressurizing the AC voltage is selected from 1000V below the range of 5V to the injection means. The first power supply applies a potential selected from a range of −200 KV or more and −10 KV or less, or +10 KV or more and +200 KV or less to the collection electrode,
2. The nanofiber manufacturing apparatus according to claim 1, wherein the AC power source applies an AC voltage selected from a range of 5 V to 1000 V to the ejection unit. A non-woven fabric manufacturing apparatus comprising an injection means having an injection hole for injecting a raw material liquid for producing nanofibers, and a collecting electrode for collecting nanofibers injected and manufactured from the injection holes,
A deposition means disposed on the injection hole side of the collecting electrode and holding the manufactured nanofibers in a deposited state;
Moving means for moving the deposition means in a predetermined direction;
A first power source for applying a voltage selected from a range of 10 KV or more and 200 KV or less between the collecting electrode and the ejection unit;
Nonwoven fabric manufacturing apparatus comprising an AC power source for signs pressurizing the AC voltage is selected from 1000V below the range of 5V to the injection means. The first power supply applies a potential selected from a range of −200 KV or more and −10 KV or less, or +10 KV or more and +200 KV or less to the collection electrode, and the AC power supply ranges from 5 V to 1000 V to the ejection unit. The nonwoven fabric manufacturing apparatus of Claim 3 which applies the alternating voltage selected from these. A nanofiber manufacturing method applied to a nanofiber manufacturing apparatus, comprising: an injection means having an injection hole for injecting a raw material liquid for producing nanofibers; and a collecting electrode for collecting the nanofibers injected and manufactured from the injection holes. And
A voltage selected from a range of 10 KV or more and 200 KV or less is applied between the collecting electrode and the ejection unit,
The AC voltage is selected from 1000V below the range of 5V to sign addition to the injection means,
A nanofiber manufacturing method for obtaining nanofibers by flying the raw material liquid in an electric field generated by the potential state.

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