JP2008038312A - Polymer solution feed member, electrostatic spinning apparatus, and method for producing electrospun nonwoven fabric - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer solution feed member an electrostatic spinning apparatus, and a method for producing electrospun nonwoven fabrics, which are capable of producing nonwoven fabrics in high productivity using an electrostatic spinning apparatus. <P>SOLUTION: The polymer solution feed member is such as to be designed to feed a polymer solution used for an electrostatically spinning process into a spinning space. The feed member consists of a hollow pipe with a hollow space, and includes through-holes penetrating from the inner circumferential wall to the outer circumferential wall of the hollow space. The electrostatic spinning apparatus is such as to include the feed member. The method for producing the electrospun nonwoven fabrics uses the electrostatic spinning apparatus. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a polymer solution supply member, an electrospinning apparatus, and a method for producing an electrospun nonwoven fabric. More specifically, the present invention relates to a polymer solution supply member, an electrospinning apparatus, and a method for producing an electrospun nonwoven fabric that can produce an electrospun nonwoven fabric with high productivity.

  If the fiber diameter of the fibers that make up the nonwoven fabric is small, the fiber diameter of the fibers that make up the nonwoven fabric is excellent because it has excellent performance such as separation performance, liquid retention performance, wiping performance, concealment performance, insulation performance, or flexibility. Is preferably small. As a method for producing a nonwoven fabric composed of fibers having such a small fiber diameter, a polymer solution is supplied to the spinning space, and an electric field is applied to the supplied polymer solution to fiberize the polymer solution. A so-called electrospinning method is known in which a non-woven fabric is directly collected after forming.

  When manufacturing a nonwoven fabric by such an electrospinning method, it was common to use a metal nozzle having a tip such as an injection needle as a polymer solution supply member for supplying a polymer solution to a spinning space. Since such a polymer solution supply member preferably uses a plurality of nozzles of two or more in order to increase the productivity of the nonwoven fabric, the applicant of the present application circulates and moves a large number of nozzles in an oval shape, A method for improving the productivity of the nonwoven fabric was proposed (Patent Document 1). According to this method, although the productivity of the nonwoven fabric can be improved, it is necessary to replace the nozzle after a certain period of time or to clean the nozzle in order to ensure the stability of the quality. Replacing or cleaning them is a very complicated operation due to the large number of nozzles, and in this respect, the productivity of the nonwoven fabric is poor. In addition, since fibers may adhere to the tip of the nozzle during non-woven fabric production, that is, spinning, it is necessary to remove the adhered fibers in order to ensure the quality stability, but the nozzle circulates and moves. Therefore, it is difficult to remove the attached fibers, and stable production may be difficult. Furthermore, there is a method of increasing the supply amount of the polymer solution to the spinning space as one method for increasing the productivity of the nonwoven fabric. However, when a nozzle is used as the polymer solution supply member, the supply amount may be increased too much. However, it was difficult to increase productivity from this point.

JP 2006-112023 A (Claims etc.)

  The present invention has been made to solve the above problems, and provides a polymer solution supply member, an electrospinning apparatus, and a method for producing an electrospun nonwoven fabric capable of producing an electrospun nonwoven fabric with high productivity. For the purpose.

  The invention according to claim 1 of the present invention is “a polymer solution supply member for supplying a polymer solution to a spinning space, used in an electrospinning method, wherein the polymer solution supply member comprises a hollow tube having a hollow portion; A polymer solution supply member comprising a through-hole penetrating from the inner peripheral wall of the hollow portion to the outer peripheral wall. "

  The invention according to claim 2 of the present invention is “a polymer solution supply member characterized in that a portion through which the through hole of the outer peripheral wall passes is flat or recessed”.

  The invention according to claim 3 of the present invention is “an electrostatic spinning device including the polymer solution supply member according to claim 1 or 2”.

  The invention according to claim 4 of the present invention is “a method for producing an electrospun nonwoven fabric using the electrospinning apparatus according to claim 3”.

  The invention according to claim 1 of the present invention can be easily carried out regardless of whether it is replaced or washed because the polymer solution supply member comprises a hollow tube. Further, even if fibers adhere during spinning, they do not protrude like a nozzle, so it is easy to remove the adhered fibers. Furthermore, since the polymer solution supply member comprises a hollow tube, surface tension is likely to act on the polymer solution, and the polymer solution is easily held on the outer peripheral wall of the polymer solution supply member, so the amount of supply of the polymer solution to the spinning space can be reduced. Can do a lot. As a result, an electrospun nonwoven fabric can be produced stably and with high productivity.

  In the invention according to claim 2 of the present invention, the portion of the outer peripheral wall through which the through-hole penetrates is flat or depressed, so that the surface tension is more likely to act on the polymer solution, and the polymer solution is applied to the outer peripheral wall of the polymer solution supply member. Therefore, the amount of the polymer solution supplied to the spinning space can be further increased, and the electrospun nonwoven fabric can be produced with higher productivity.

  Since the invention according to claim 3 of the present invention is provided with the polymer solution supply member according to claim 1 or 2, it is an apparatus capable of producing an electrospun nonwoven fabric stably and with high productivity.

  Since the invention according to claim 4 of the present invention is a method using the electrospinning apparatus according to claim 3, it is a method capable of producing an electrospun nonwoven fabric stably and with high productivity.

  The polymer solution supply member of the present invention will be described with reference to FIGS. FIG. 1 is a schematic perspective view of a polymer solution supply member, and FIG. 2 is a cross-sectional view of the polymer solution supply member.

  The polymer solution supply member 1 of the present invention comprises a hollow tube 1 having a hollow portion 2 and is provided with a plurality of through holes 3 penetrating from the inner peripheral wall of the hollow portion 2 to the outer peripheral wall. Since the polymer solution supply member 1 of the present invention has such a configuration, the polymer solution is supplied from the polymer solution reservoir to the hollow portion 2 of the polymer solution supply member 1, and the supplied polymer solution is passed through the through hole 3. Supplied to the spinning space. As can be seen from FIG. 1, the polymer solution supply member 1 of the present invention can be replaced by replacing the polymer solution supply member 1. When cleaning, the outer peripheral wall surface of the polymer solution supply member 1 is smooth. It is easy to clean. Further, even if fibers adhere during spinning, the outer peripheral wall surface is smooth, so that it is easy to remove the adhered fibers. Further, since the surface tension is easily applied to the polymer solution supplied from the polymer solution supply member 1 (hollow tube 1) and the polymer solution is easily held on the outer peripheral wall of the polymer solution supply member 1, the spinning space of the polymer solution is reduced. The amount of supply to can be increased. Therefore, the polymer solution supply member 1 of the present invention can produce an electrospun nonwoven fabric stably and with high productivity.

  The hollow tube as the polymer solution supply member of the present invention may have any shape as long as the polymer solution can be supplied to the spinning space. Another shape of the polymer solution supply member will be described with reference to FIGS. In FIG. 3, the cross-sectional shape is a semicircular shape, and the through hole 3 penetrates from the inner peripheral wall of the hollow portion 2 to the curved outer peripheral wall. Thus, the polymer solution supply member 1 need not have a circular cross-sectional shape. In FIG. 3, only one through-hole 3 is drawn, but only one is drawn because it is arranged in a straight line. The same applies to the following figures.

  In FIG. 4, the cross-sectional shape is a square shape (square shape), and the through hole 3 penetrates from the inner peripheral wall of the hollow portion 2 to the flat outer peripheral wall. As described above, when the portion through which the through-hole 3 passes is a flat outer peripheral wall, the polymer solution supplied from the through-hole 3 is easily held by the flat outer peripheral wall due to surface tension. The supply amount can be increased, and an electrospun nonwoven fabric can be produced with higher productivity. In FIG. 5, the cross-sectional shape is a semicircular shape, and the through hole 3 penetrates from the inner peripheral wall of the hollow portion 2 to the flat outer peripheral wall. In this case, similarly to the polymer solution supply member 1 of FIG. 4, the supply amount of the polymer solution to the spinning space can be increased, and the electrospun nonwoven fabric can be manufactured with higher productivity. FIG. 6 shows the polymer solution supply member 1 in which the flattening auxiliary material 4 is attached to the hollow tube 1 having a circular cross-sectional shape so that the portion through the through hole 3 is flat. Since this polymer solution supply member 1 also has a flat outer peripheral wall through the through hole 3, the amount of polymer solution supplied to the spinning space can be increased in the same manner as the polymer solution supply member 1 of FIG. Thus, the electrospun nonwoven fabric can be produced with higher productivity.

  7 has a circular cross-sectional shape and includes two rows of through holes 3a and 3b penetrating from the inner peripheral wall of the hollow portion 2 to the outer peripheral wall. When two or more rows of through-holes 3a and 3b are provided in this way, the amount of the polymer solution supplied to the spinning space can be increased accordingly, so that the electrospun nonwoven fabric can be produced with higher productivity. it can. In FIG. 8, the cross-sectional shape is a quadrangular shape (square shape), and two rows of through holes 3a and 3b penetrating from the inner peripheral wall of the hollow portion 2 to the flat outer peripheral wall are provided. Thus, in addition to the fact that surface tension is likely to be exerted by the through-holes 3a and 3b being flat outer peripheral walls, the through-holes 3a and 3b are arranged in two rows, thereby further entering the spinning space. Therefore, the electrospun nonwoven fabric can be produced with higher productivity.

  FIG. 9 shows an outer peripheral wall having a crescent-shaped cross section, and a portion in which the through hole 3 penetrates from the inner peripheral wall of the hollow portion 2 has a dent curved toward the hollow portion. By having such a recessed outer peripheral wall, surface tension is likely to act, and the amount of polymer solution retained increases, so the amount of polymer solution supplied to the spinning space can be increased, and electrostatic spinning with high productivity. Nonwoven fabrics can be manufactured. FIG. 10 shows an outer peripheral wall having a substantially quadrangular cross-sectional shape, and a portion in which two rows of through holes 3a and 3b penetrate from the inner peripheral wall of the hollow portion 2 has depressions curved toward the hollow portion. Thus, in addition to the fact that the through-holes 3a and 3b penetrate through the recesses in the outer peripheral wall, surface tension is likely to act, and the through-holes 3a and 3b are arranged in two rows, so Since the supply amount of the polymer solution can be increased, the electrospun nonwoven fabric can be produced with higher productivity.

  In these drawings, the flat portion or the recess extends continuously in the length direction of the polymer solution supply member. However, the polymer solution supply member of the present invention is not limited to such an embodiment, and is penetrated. It may be an outer peripheral wall having a partially flat portion or depression, such as having a flat portion or depression only around or on both sides of the hole. In these drawings, the hollow portion 2 of the polymer solution supply member (hollow tube) is substantially similar to the shape of the outer peripheral wall, but need not be similar. That is, the thickness of the peripheral wall of the hollow tube does not need to be constant. The number of rows of through holes is not particularly limited, and may be three or more. Furthermore, although the polymer solution supply member of FIG. 1 is illustrated with respect to a rod-shaped embodiment, it is not necessary to have a rod shape, and may be a circular ring shape or an oval ring shape. In the case of a circular ring shape or an oval ring shape and the hollow tube is made of a flexible material, a non-woven fabric with uniform basis weight is manufactured by moving the polymer solution supply member into a circular shape or an oval shape. be able to. Such a flexible hollow tube constituent material is not particularly limited as long as it is not affected by the solvent constituting the polymer solution. For example, perfluoroalkoxy resin, polytetrafluoroethylene, fluoride Fluorine resins such as ethylene propylene and fluoro rubber, polyolefin resins such as polyethylene, polypropylene and copolymer polypropylene, polyamide resins such as 6 nylon and copolymer nylon, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, etc. These resins can be used alone or in combination with a two-layer structure or the like.

  Since the electrospinning apparatus of the present invention includes the polymer solution supply member of the present invention as described above, the polymer solution supply member can be easily replaced or washed, and even if fibers are attached during spinning, it can be easily removed. In addition, since the supply amount of the polymer solution to the spinning space can be increased, the electrospun nonwoven fabric can be manufactured stably and with high productivity.

  The electrospinning apparatus of the present invention is exactly the same except that the polymer solution supply member of the present invention as described above is used in place of a conventional polymer solution supply member (for example, a nozzle). For example, a polymer solution supply device that can supply a polymer solution to a polymer solution supply member, a polymer solution supply member of the present invention that can supply a polymer solution to a spinning space, a trap that collects fibers supplied to the spinning space and drawn by an electric field. And an electric field forming device capable of forming an electric field between the polymer solution supplied to the collecting body and the spinning space and the collecting body. Preferably, in order to prevent dispersion of the solvent of the polymer solution, a spinning container that can store the polymer solution supply member and the collector, a gas supply device that can supply a gas having a predetermined relative humidity to the spinning container so that the fiber diameter can be easily aligned, Alternatively, an exhaust device capable of exhausting the gas in the spinning container is provided. Conventionally, since a metal nozzle was used, it was possible to apply a voltage to the nozzle. However, when the polymer solution supply member of the present invention is made of a nonmetal, the polymer solution supply device and the polymer A polymer solution supply pipe between the solution supply member and / or a metal wire or the like can be installed in the polymer solution supply member to form an electric field between the polymer solution and the collector.

  In addition, the polymer solution supply member has a rod-shaped member as shown in FIG. 1 arranged in one or more rows in the width direction of the collection body (perpendicular to the traveling direction) and fixed, or of the collection body. The polymer solution can be supplied to the spinning space while reciprocating in the width direction, and the polymer solution can also be supplied to the spinning space while circulating the circular ring-shaped or oval ring-shaped polymer solution supply member. In the case of an oval ring-shaped polymer solution supply member, it is preferable to circulate and move the major axis so as to coincide with the width direction of the collector. By doing in this way, the nonwoven fabric with the same fabric weight can be manufactured.

  Since the method for producing an electrospun nonwoven fabric of the present invention is a method of producing using an electrospinning apparatus as described above, it can be produced with high productivity. In addition, since the fiber which comprises an electrospun nonwoven fabric changes with uses of an electrospun nonwoven fabric, by changing the polymer solution to spin, the kind of fiber can be changed and it can be adapted to a use. Examples of polymers constituting the polymer solution include polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene copolymer, polyacrylonitrile (PAN), polyacrylonitrile-methacrylate copolymer, polymethyl methacrylate, polyvinyl chloride. , Polyvinylidene chloride-acrylate copolymers, nylons such as polyethylene, polypropylene, nylon 12, nylon-4,6, aramid, polybenzimidazole, polyvinyl alcohol, cellulose, cellulose acetate, cellulose acetate butyrate, polyvinylpyrrolidone-acetic acid Vinyl, poly (bis- (2- (2-methoxy-ethoxyethoxy)) phosphazene) (poly (bis- (2- (2-methoxy-ethyoxy))) ph sphazene); MEEP), polypropylene oxide, polyethylene imide (PEI), polysuccinic acid ethylene (poly (ethylenesuccinate)), polyaniline, polyethylene sulfide, polyoxymethylene-oligo-oxyethylene (poly (oxymethylene-oligo-oxyethylene)), SBS copolymer, polyhydroxybutyric acid, polyvinyl acetate, polyvinyl alcohol (PVA), polyethylene terephthalate, polyethylene oxide, collagen, polylactic acid, polyglycolic acid, poly D, L-lactic acid-glycolic acid copolymer, polyarylate, High biodegradability such as polypropylene fumarate (polypropylene fumarates) and polycaprolactone Various polymers that can be melted or dissolved in an appropriate solvent, such as biopolymers such as polymers, polypeptides, proteins, etc., pitch systems such as coal tar pitch, petroleum pitch, etc. are applicable, and their copolymers and mixtures are also used Is possible. A spinnable sol solution obtained by hydrolyzing a metal alkoxide can also be used. The polymer solution may be mixed with an emulsion such as a synthetic resin or an organic or inorganic powder.

  Examples of the polymer solvent include (a) highly volatile acetone, chloroform, ethanol, isopropanol, methanol, toluene, tetrahydrofuran, water, benzene, benzyl alcohol, 1,4-dioxane, propanol, carbon tetrachloride, cyclohexane, (B) N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N, N-dimethylacetamide (DMAc) with relatively low volatility, such as cyclohexanone, methylene chloride, phenol, pyridine, trichloroethane, and acetic acid 1-methyl-2-pyrrolidone (NMP), ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), acetonitrile (AN), N-methylmorpholine-N-oxide, butylene Carbonate (BC), 1,4-butyrolactone (BL), diethyl carbonate (DEC), diethyl ether (DEE), 1,2-dimethoxyethane (DME), 1,3-dimethyl-2-imidazolidinone (DMI) 1,3-dioxolane (DOL), ethyl methyl carbonate (EMC), methyl formate (MF), 3-methyl oxazolidine-2-one (MO), methyl propionate (MP), 2-methyl tetrahydrofuran (MeTHF) ) And sulfolane (SL). The use of the highly volatile solvent or a mixed solvent in which a highly volatile solvent and a solvent having a relatively low volatility are used increases the volatility of the solvent or decreases the viscosity of the polymer solution. The discharge amount from the polymer solution supply member can be increased, and the productivity of the electrospun nonwoven fabric can be improved.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but these do not limit the scope of the present invention.

(Example 1)
(1) Preparation of spinning stock solution;
A polymer solution (viscosity: 1220 mP · s) in which polyacrylonitrile (registered trademark: Bonnell, manufactured by Mitsubishi Rayon Co., Ltd.) was dissolved in N, N-dimethylformamide to a concentration of 14 mass% was prepared.

(2) Preparation of manufacturing equipment;
A hollow tube made of perfluoroalkoxy resin having an inner diameter of 4 mm and an outer diameter of 6 mm (cross-sectional shape: the hollow part and the outer peripheral wall are both circular (same as in FIG. 2), length: 300 mm), and a through-hole having a diameter of 0.2 mm is provided. A polymer solution supply member was formed by forming 5 pieces in a row at a pitch of 60 mm.

  Next, a micropump (manufactured by Micropump; Micropump FC-513, pump head: 188 1 rpm = 0.17 mL type; controller unit: manufactured by Chuo Rika Co., Ltd., polymer solution supply device) is connected to a polyethylene flexible bag, A perfluoroalkoxy resin tube (with a 0.1 mm diameter stainless steel wire inserted) was connected, and this tube was connected to the polymer solution supply member described above.

  Next, a belt-like collector (width: 500 mm) made of a steel belt coated with conductive silicone rubber was grounded and placed below the polymer solution supply member. Next, a high voltage power source is connected to the gear pump head of the micropump, the through holes of the polymer solution supply member are directed toward the belt-shaped collector, and the arrangement direction of the through holes is the width direction of the belt-shaped collector ( The polymer solution supply member was arranged so as to coincide with the direction perpendicular to the moving direction. In addition, the distance of the through-hole edge part in an outer peripheral wall and the collection surface of a belt-shaped collection body was 100 mm.

  Next, the polymer solution supply member and the belt-shaped collection body were disposed in the center of a vinyl chloride rectangular parallelepiped spinning container (width: 800 mm, height: 1300 mm, depth: 1800 mm). Inside the rectangular parallelepiped spinning vessel, a vinyl chloride punching plate is placed parallel to the upper wall surface at a position 500 mm below the upper wall surface, and a vinyl chloride punching plate is placed 100 mm above the lower wall surface at the lower wall surface. Placed in parallel. Moreover, the paper tube was arrange | positioned as the winding device at the moving direction end part of the belt-shaped collector. This paper tube was rotated by the movement of the belt-shaped collector, and could wind up the electrospun nonwoven fabric.

  And while connecting the blower (PAU-1400HDR, Apiste Co., Ltd., gas supply apparatus) provided with the temperature / humidity adjustment function to the upper wall surface of the rectangular parallelepiped spinning vessel, an exhaust fan was connected to the lower wall surface of the rectangular parallelepiped spinning vessel.

(3) Production of electrospun nonwoven fabric;
The polymer solution is put in a polyethylene flexible bag, the polymer solution is supplied to a polymer solution supply member using the micropump, and the supplied polymer solution is supplied from each through hole to a spinning space (amount supplied per one: 5 cc / hour), a voltage of +15 kV is applied to the polymer solution from the high-voltage power source, an electric field is applied to the supplied polymer solution to form fibers, and the fibers are accumulated on the belt-shaped collector, and the average fiber diameter An electrospun non-woven fabric (weight per unit area: 4.5 g / m ² ) composed of continuous fibers of 0.35 μm was produced. When producing an electrospun non-woven fabric, humidity control air at a temperature of 25 ° C. and a relative humidity of 25% is supplied from a gas supply device at 5 m ³ / min. Exhausted. In addition, when the polymer solution was supplied to the spinning space and spun, fibers sometimes adhered, but could be easily removed.

(Comparative Example 1)
A linear stainless steel tube (inner diameter: 4 mm, outer diameter: 6 mm, length: 300 mm), linearly, 5 nozzles at the same interval with a pitch of 60 mm (each stainless steel needle-shaped nozzle with an inner diameter of 0.4 mm) ) Are arranged in a row, and an electrospun non-woven fabric composed of continuous fibers having an average fiber diameter of 0.35 μm is the same as in Example 1 except that this polymer solution supply member was used. The basis weight was 4.5 g / m ² ). In this case, the supply amount of the polymer solution from the nozzle to the spinning space was 3 cc / hour per one, the supply amount was smaller than that in Example 1, and the productivity was inferior. Further, when the polymer solution was supplied to the spinning space and spun, the fibers sometimes adhered to the tip of the nozzle, but it was difficult to remove the fibers.

Schematic perspective view of polymer solution supply member Cross-sectional view of the polymer solution supply member of FIG. Cross section of another polymer solution supply member Cross-sectional view of still another polymer solution supply member Cross-sectional view of still another polymer solution supply member Cross-sectional view of still another polymer solution supply member Cross-sectional view of still another polymer solution supply member Cross-sectional view of still another polymer solution supply member Cross-sectional view of still another polymer solution supply member Cross-sectional view of still another polymer solution supply member

Explanation of symbols

1: Polymer solution supply member (hollow tube)
2: Hollow part 3, 3a, 3b: Through hole 4: Flattening auxiliary material

Claims (4)

A polymer solution supply member for supplying a polymer solution to a spinning space, which is used in an electrospinning method. The polymer solution supply member includes a hollow tube having a hollow portion, and penetrates from an inner peripheral wall of the hollow portion to an outer peripheral wall. A polymer solution supply member comprising a through hole. The polymer solution supply member, wherein a portion of the outer peripheral wall through which the through hole passes is flat or depressed. An electrospinning apparatus comprising the polymer solution supply member according to claim 1. A method for producing an electrospun nonwoven fabric using the electrospinning apparatus according to claim 3.

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