JP2008540868A - Filament bundle nano-long fibers and method for producing the same - Google Patents

Abstract

  The present invention relates to a spinning solution produced by dissolving two or more kinds of polymer blends or copolymers in a solvent, or a spinning melt produced by melting the polymer. Electrospun as droplets from a nozzle, the droplets to be spun were produced by continuously collecting on a multiple collector consisting of a single shape or a combination of these selected from a plate shape and a roll shape, Disclosed is a filament bundle of nano-sized long fibers and a method for producing the same. The filament bundle-like nano-sized long fibers of the present invention are manufactured in the form of yarns in one step during the electrospinning process, thereby improving the mechanical properties compared to conventional nanofiber nonwoven fabrics. Can be expanded and applied.

Description

Detailed Description of the Invention

〔Technical field〕
The present invention relates to a filament bundle of nano-sized long fibers and a method for producing the same, and more specifically, a spinning solution produced by dissolving two or more polymer blends or copolymers in a solvent, or A spinning melt produced by melting the polymer is electrospun as a droplet from a spinning nozzle to which a critical voltage is applied, and the spun droplet is selected from a plate shape and a roll shape alone or The present invention relates to a filament bundle-like nano-sized long fiber that is continuously collected on a multi-collector having a shape of these combinations and is manufactured using an improved electrospinning method and a method for manufacturing the same.

[Background Technology]
Nanofibers are ultrafine fibers having a fiber diameter of 1 to 1000 nm and provide various physical properties that cannot be obtained with existing fibers. Nanofiber webs are porous separation membrane materials, such as various filters, wound dressings, artificial support biochemical weapon defense clothing, secondary battery separator membranes, nanocomposites, etc. It can be used very usefully in various fields.

  A known method for producing nanofibers is typically an electrospinning method in which a fiber raw material solution is spun in a charged state to produce fine-diameter fibers. Examples of producing nanofibers using the electrospinning method include Korean published patents 2000-11018, 2003-3925, 2003-77384, and US Pat. No. 6,183,670. Is known. However, nanofibers produced by a known electrospinning method are limited to a nonwoven fabric. In this regard, Doshi et al. Generally collect droplets of a polymer solution generated at the tip of a spinning nozzle in a conventional electrospinning method while being collected on a collector while bursting under high voltage application. In the process of producing nanofibers, nanofibers are accumulated in an anisotropic orientation rather than an isotropic orientation on the collector. [Doshi and Reneker, "Electrospinning Process and Application", Journal of Electrostatics, 1995, 35, 151-160].

  In addition, since such a non-woven nanofiber is made of a single fiber, a process in which a droplet generated at the tip of a spinning nozzle during electrospinning is spun toward a collector under a critical voltage (Vc). In addition, it is pointed out that the single fibers collide before reaching the collector, and as a result, they interfere with each other or combine to form agglomerates. For this reason, Korean Published Patent Publication No. 2002-50381 discloses that nanofibers are produced by a conventional electrospinning method using polyethylene terephthalate and a copolyester as a spinning solution instead of a single component. However, the nanofibers produced above do not deviate from the nonwoven fabric. The non-woven nanofibers are very weak in mechanical strength. Particularly when the non-woven nanofibers are twisted to produce yarns, separate connecting fibers for connecting the single fibers during the production. Is necessary, and the problem that the finally manufactured yarn is likely to be broken is induced, so that improvement is urgently required for application to various required fields.

  Therefore, as a result of efforts to obtain nanofibers that can be satisfied in a wider variety of fields, the present inventors have obtained a solution of the spinning solution generated at the tip of the spinning nozzle in the conventional electrospinning method. In the process of droplets being collected on a collector while bursting under high voltage application to produce nanofibers, the spinning solution is spouted onto one or more primary collectors to produce nanofibers Filament bundles having a diameter of 1 to 15 μm, which has better mechanical properties than conventional nanofibers, by collecting nanofibers collected on the primary collector and collecting them continuously on the secondary collector. The present inventors have found that the nanofibers can be continuously produced and have completed the present invention.

[Disclosure of the Invention]
[Technical issues]
An object of the present invention is to provide nano-sized long fibers in the form of bundles of filaments.

  Another object of the present invention is to electrospin a spinning solution or spinning melt as droplets from a spinning nozzle to which a critical voltage is applied, and to discharge the spun droplets onto one or more primary collectors. After the nanofibers are generated, the nanofibers collected on the primary collector are recollected on the secondary collector and continuously collected. At this time, at least one collector rotates. Another object of the present invention is to provide a method for producing the filament bundle-like nano-sized long fibers.

  Another object of the present invention is to design the molecular structure suitable for electrospinning, or to provide the optimum blending condition of the compound having the appropriate molecular structure, and the filament bundle-like nano-sized long fiber. It is in providing the manufacturing method of.

[Technical Solution]
In order to achieve the above object, the present invention provides a spinning solution produced by dissolving two or more polymer blends or copolymers in a solvent, or a spinning melt produced by melting the polymer. Electrospun as droplets from a spinning nozzle to which a critical voltage is applied, and the spun droplets are continuously formed on a multiple collector composed of a single shape or a combination thereof selected from a plate shape and a roll shape. The present invention provides nanofibers in the form of filament bundles that are collected and manufactured.

  In this case, the polymer is composed of a combination of two or more selected from the group consisting of polyimide, polyamide, polyethylene, polypropylene, polyester, vinylidene fluoride resin, polyacrylonitrile, polysulfone and polyethylene oxide, more preferably monoamine, It contains one or more amine groups selected from the group consisting of diamines, triamines and tetraamines. The most preferred polymer in the present invention is a polyamide-polyimide copolymer.

  As a preferable solvent, any one selected from the group consisting of N-methyl-2-pyrrolidone, γ-butyrolactone, 2-butoxyethanol, dimethylacetamide and dimethylformamide is used.

  The present invention also provides a filament yarn made of continuous fibers having a nano size of 1 to 1000 nm manufactured into a continuous yarn bundle.

  The present invention provides a method for producing a long fiber having a nanosize of 1 to 1000 nm. More specifically, in the production method of the present invention, 1) a spinning solution produced by dissolving 10 to 50% by weight of two or more polymer blends or copolymers in a solvent, or the polymer at a melting temperature A spinning melt produced by heating and melting as described above is prepared, 2) the spinning solution or spinning melt is electrospun as droplets from a spinning nozzle to which a critical voltage is applied, and 3) the spinning is performed. The nanofibers are ejected onto the primary collector to form nanofibers, and then the nanofibers collected on the primary collector are collected again on the secondary collector and continuously collected. The at least one collector rotates. In addition to the primary collector and the secondary collector, one or more collectors may be further provided.

  The primary collector is made of an electrically conductive metal plate or metal mesh and is preferably plate-shaped and can be fixed or rotated at 1-1000 rpm. The secondary collector is a tube or rod made of glass or plastic made of a material capable of generating static electricity, or a tube or rod coated with the material. The secondary collector is preferably in the form of a roll that rotates at 1 to 100 rpm.

  In the production method of the present invention, during electrospinning, the distance between the spinning nozzle and the primary collector is preferably 1 to 50 cm, and the distance between the primary collector and the secondary collector is preferably 1 to 50 cm.

[Advantageous effects]
As described above, the filament bundle-like nano-sized long fibers produced by the improved electrospinning method according to the present invention have improved mechanical properties compared to conventional nanofiber nonwoven fabrics, and the conventional micron-diameter fibers are Alternative use is possible in all utilized fields. For example, the fiber of the present invention is useful firstly as a medical filter for kidney dialysis and blood purification and various membrane reinforcing materials for gene separation, and secondly, in the electrical and electronic field, an ultra-thin reinforcing plate and It is useful for manufacturing an ultra-thin PCB substrate, and thirdly, it can be applied to an ultra-compact ultralight aircraft or an unmanned adjustment flying robot, and fourthly, it is useful as a reinforcing material for optical cables in the optical communication field.

[Best Mode for Carrying Out the Invention]
Hereinafter, the present invention will be described in detail.

  The present invention relates to a spinning solution produced by dissolving two or more kinds of polymer blends or copolymers in a solvent, or a spinning melt produced by melting the polymer. Electrospun as droplets from a nozzle, the droplets to be spun were produced by continuously collecting on a multiple collector consisting of a single shape or a combination of these selected from a plate shape and a roll shape, To provide nano-sized long fibers in the form of filament bundles.

  More specifically, at the time of the electrospinning, droplets to be spun are discharged onto the primary collector to generate nanofibers, and then the nanofibers accumulated on the primary collector are placed on the secondary collector. Recollecting and continuously collecting, at this time, at least one collector rotates. Thereby, it is possible to provide a filament bundle yarn having a filament size that is manufactured as a continuous yarn bundle and has a nano-size twist of 1 to 1000 nm (FIGS. 2, 5, 7, 9, and 9). 11 and FIG. 13).

  On the other hand, the nanofiber manufactured using the conventional electrospinning method is manufactured in the form of a net-like nonwoven fabric (FIGS. 15 and 16). When the manufactured short fiber is manufactured as a continuous yarn, since the short fiber is connected and manufactured, there is a conventional problem that yarn breakage is likely to occur. On the other hand, the present invention is continuous by a continuous process. Since it is produced into yarn, nanofibers in which yarn breakage is not found can be produced in one step.

1. Production of Spinning Solution or Spinning Melt The nanofiber of the present invention can be realized by designing a molecular structure suitable for electrospinning or by providing optimum compounding conditions for a compound having an appropriate molecular structure.

  More specifically, the polymer for producing the spinning solution of the present invention is not particularly limited as long as it is excellent in miscibility with a solvent and excellent in mechanical strength. More preferably, it is polyimide, polyamide. A combination of two or more selected from the group consisting of polyethylene, polypropylene, polyester, vinylidene fluoride resin, polyacrylonitrile, polysulfone and polyethylene oxide is used. More preferably, the polymer of the present invention contains one or more amine groups selected from the group consisting of monoamines, diamines, triamines, and tetraamines. Examples of the diamine include phenylenediamine, oxyferrenine diamine, and Selected from the group consisting of alkylphenylenediamines.

  Most preferably, the polymer is a polyamide-polyimide copolymer composed of a compound represented by Chemical Formula 1 and a compound represented by Chemical Formula 2.

  In the chemical formula, m is preferably 10 to 50 mol%. At this time, if m is less than 10 mol%, there is a problem that crystallization is small and becomes very flexible, and if m is 50 mol% or more, There is a disadvantage that crystallization is large and impact resistance is low. The n is preferably 50 to 90 mol%, and if it is less than 50 mol%, the crystallization is large and impact resistance is low, and if it exceeds 90 mol%, the crystallization is small and becomes very flexible. It is not preferable.

  The polyamide-polyimide copolymer (m + n) has a number average molecular weight of about 500 to 1,000,000. At this time, when the number average molecular weight is less than 500, the molecular weight is low and the viscosity and mechanical strength are low, and when the number average molecular weight exceeds 1,000,000, the viscosity increases as the molecular weight increases. There is a drawback that it becomes too large and difficult to process.

  The polymer used for conventional electrospinning is composed of a one-component phase, whereas the polymer selected in the present invention is a blend or copolymer composed of a two-component phase. Therefore, when the cone generated at the tip of the spinning nozzle is spun toward the collector under the critical voltage (Vc) during conventional electrospinning, the single fibers collide before reaching the collector. However, by interfering with or bonding to each other, agglomerates are formed to obtain non-woven fine fibers, whereas the two-component polymer blend or copolymer of the present invention has interference between single fibers or By preventing bonding, a continuous yarn can be produced.

  A preferable solvent capable of dissolving the polymer is not particularly limited as long as it can sufficiently dissolve the polymer. More preferably, N-methyl-2-pyrrolidone, γ-butyrolactone is used. Any one selected from the group consisting of 2-butoxyethanol, dimethylacetamide, and dimethylformamide is used, and N-methyl-2-pyrrolidone is more preferably used.

  The inherent critical voltage (Vc) differs depending on the viscosity of the polymer solution even if the same polymer is used, and the difference in frictional force on the polymer solution occurs depending on the diameter and material of the spinning nozzle. The arrival speed of the polymer solution to the lowest end and the shape of the cone of the droplet generated thereafter are different. However, the diameter and material of the spinning nozzle indirectly affect the formation of the droplet cone during electrospinning, but the concentration of the polymer solution acts as the most important factor. Therefore, during electrospinning, the discharge rate (mL / min) of the polymer solution and the degree of droplet formation at the tip of the spinning nozzle differ depending on the concentration of the polymer solution. Therefore, the polymer solution of the present invention preferably contains 10 to 50% by weight of the polymer with respect to the solvent. At this time, if it is less than 10% by weight, it shows a yarn breakage phenomenon in which the spun fiber is cut, and if it exceeds 50% by weight, the viscosity greatly increases, so that the shape of the cone generated at the tip of the nozzle is not good. The problem of becoming stable occurs.

  Accordingly, in a preferred embodiment of the present invention, when electrospinning is performed using a stainless steel tube having a spinning nozzle diameter of 0.42 mm, the spinning solution of the present invention contains polyamide-polyimide in a solvent of N-methyl-2-pyrrolidone. Preferably, the copolymer is prepared by dissolving 25% by weight of the copolymer. At this time, the discharge rate is 0.3 mL / min.

  In addition to the spinning solution produced by dissolving two or more kinds of blends or copolymers in a solvent, a spinning melt produced by melting the polymer at a melting temperature or higher can be applied to electrospinning. . The nanofiber of the present invention is an improvement of the conventional electrospinning method by introducing multiple collectors at the time of electrospinning, and any material that can be used in the conventional method can be similarly applied. For example, ceramic melt, metal melt, organic-inorganic hybrid melt, metal-organic composite melt, carbon melt, and sol-gel solution can be used. Can be obtained by heating to a temperature above the phase transition temperature.

2. Electrospinning Using Multiple Collectors The nanofiber production method of the present invention is an improvement over conventional electrospinning methods by introducing multiple collectors during electrospinning. More specifically, in the method for producing nanofibers of the present invention, 1) a spinning solution produced by dissolving 10 to 50% by weight of two or more blends or copolymers in a solvent, or the melting temperature of the polymer A spinning melt produced by heating and melting as described above is prepared, 2) the spinning solution or spinning melt is electrospun as droplets from a spinning nozzle to which a critical voltage is applied, and 3) the spinning is performed. The nanofibers are ejected onto the primary collector to form nanofibers, and then the nanofibers collected on the primary collector are collected again on the secondary collector and continuously collected. The at least one collector rotates.

  The manufacturing method may further include one or more collectors in addition to the primary collector and the secondary collector.

  The primary collector is made of a material of an electrically conductive metal plate or a metal mesh, and the shape thereof is not particularly limited, but a circular plate or a rectangular plate is a preferred plate-type collector. The size of the plate-like collector varies depending on the viscosity of the polymer solution and the critical voltage Vc thereby, but it may be larger than the collection area of the nanofibers produced by spinning from the spinning nozzle. The distance between the spinning nozzle and the primary collector is preferably 1 to 50 cm. At this time, if the distance between the spinning nozzle and the primary collector is less than 1 cm, particles are formed and fibers are not stably formed. If the distance exceeds 50 cm, the spun nanofibers are out of the collector region. So it is inefficient.

  The primary collector may be positioned vertically or horizontally with respect to the spinning nozzle and may comprise one or more and may be fixed to the bottom surface or rotated at a constant speed. When the primary collector rotates, the preferred rotation speed can be changed depending on the degree of twist of the nanofiber to be obtained, but is in the range of 1-1000 rpm. At this time, if the rotation speed is 1 rpm or less, the rotation speed is slow and is concentrated in a specific part, and if it rotates at a speed as high as 1000 rpm or more, nanofibers are not sufficiently generated from the spinning nozzle, and the yarn There is a problem that the cutting phenomenon occurs and the yield of nanofibers is lowered.

  The secondary collector is a material capable of generating static electricity, and a glass or plastic tube or rod, or a tube or rod coated with the material can be used. The secondary collector is a roll-type collector that rotates at 1 to 100 rpm. At this time, the distance between the primary collector and the secondary collector and the rotational speed of each collector can be determined by the diameter of the nanofiber to be obtained and the degree to which the fiber is not cut. The distance between the primary collector and the secondary collector is preferably 1 to 50 cm. At this time, if the length is less than 1 cm, there is a problem that the fibers are entangled, and if it exceeds 50 cm, the fibers may be cut.

  The process of re-collecting nanofibers collected on the primary collector on the secondary collector is guided in the direction of the secondary collector using a separate charged bar on the primary collector on which nanofibers are accumulated. Or a step of moving a secondary collector after a secondary collector made of a material that generates static electricity is brought close to the primary collector and a part of the accumulated nanofibers is guided to the secondary collector. be able to.

  FIG. 1 shows a first preferred embodiment of the present invention. First, when a spinning solution is injected into the spinning solution injection section 102 and the spinning solution is supplied to the spinning nozzle 103 at a constant discharge speed, the tip of the spinning nozzle is shown. A droplet is generated. At this time, when a voltage is applied from the high voltage generator 101 set to a constant voltage, the primary disk-shaped collector 104 that rotates in a position perpendicular to the spinning nozzle 103 while the droplet bursts. Nanofibers are collected in Thereafter, using a separate charged bar, the spun nanofibers 105 accumulated on the primary disk-shaped collector 104 are guided so as to be continuously accumulated on the rotating secondary roll-shaped collector, and the nano A long fiber 106 having a size is manufactured (FIGS. 2 and 3).

  FIG. 4 shows a second preferred embodiment of the electrospinning method using the multi-collector of the present invention, in which nanofibers are placed on a primary disk-shaped collector 104 that rotates in a horizontal position with respect to the spinning nozzle 103. Accumulated. When the secondary roll collector 106 is continuously brought close to the primary disk collector 104, a part of the spun nanofiber 105 collected by the primary disk collector 104 is formed into a secondary roll. Guidance for accumulation on collector 106 (108). Thereafter, while the secondary roll collector 106 is separated from the primary disk collector 104 at a distance that does not break the spun nanofiber 105, the secondary roll collector 106 is rotated at 1 to 100 rpm. The nanofiber 107 is manufactured by extruding to the XY axis (FIG. 5).

  FIG. 6 shows a third preferred embodiment of the electrospinning method using the multiple collector according to the present invention, and a primary plate collector 104a fixed in the vertical direction with respect to the spinning nozzle 103 installed at the upper end, and A secondary plate collector 104b is disposed at an angle of 90 ° with respect to the primary plate collector 104a. At this time, the primary plate collector 104a is charged, and the secondary plate collector 104b is not charged. Droplets are continuously collected on the collector to produce nano-sized long fibers 107 (FIG. 7).

  FIG. 8 shows a fourth preferred embodiment of the electrospinning method using the multi-collector of the present invention. The primary roll collector 106a is positioned on the bottom surface in a direction perpendicular to the spinning nozzle 103 installed at the upper end. The secondary roll collector 106b is provided with a height difference of 5 to 10 cm from the primary collector 106a, and the primary roll collector 106a and the secondary roll collector 106b rotate at the same speed. Thereafter, the nanofibers spun on the primary collector 106a from the spinning nozzle 103 are collected again on the secondary collector 106b to produce the nanofiber 107 (FIG. 9).

  FIG. 10 shows a fifth preferred embodiment of the electrospinning method using the multiple collector of the present invention, in which a spinning nozzle 103 is installed at the upper end, and a primary plate-like collector 104a made of metal is fixedly installed at the lower end. A secondary plate collector 104b positioned at an angle of 90 ° with respect to the plate collector 104a is installed. The primary plate collector 104a and the secondary plate collector 104b are L-shaped double collectors composed of two plate collectors. The primary plate collector 104a and the secondary plate collector 104b are connected to each other, and an intermediate layer 109 is further provided at the lower end of the secondary plate collector 104b. The intermediate layer 109 uses a non-conductive material to charge the primary collector and the secondary collector independently. Droplets are continuously collected on the double collector to produce nanofibers 107 (FIG. 11).

  FIG. 12 shows a sixth preferred embodiment of the electrospinning method using the multiple collector according to the present invention, in which a spinning nozzle 103 is installed at the upper end, and a primary disk-shaped collector is horizontally arranged with respect to the spinning nozzle 103. A conveyor belt-like secondary roll collector 106c that can be pulled in an endless track in a direction perpendicular to the primary disk-like collector 104 is installed. Thereafter, the nanofiber 107 is manufactured while continuously passing through multiple collectors (FIG. 13).

[Mode for Carrying Out the Invention]
Hereinafter, the present invention will be described in more detail with reference to examples.

  These examples are for explaining the present invention more specifically, and do not limit the scope of the present invention.

<Production Example 1> Production of spinning solution 1
A polymer copolymer consisting of 30 mol% of an average molecular weight polyamide polymer and 70 mol% of an average molecular weight polyimide polymer is added to an N-methyl-2-pyrrolidine solvent, and 20 at room temperature using an ultrasonic device. Dissolve well for ~ 30 minutes. At this time, a spinning solution containing 25% by weight of a polyamide-polyimide copolymer having a number average molecular weight of 1000 with respect to the solvent was produced.

<Production example 2> Production of spinning solution 2
After mixing polyethylene terephthalate having an intrinsic viscosity of 0.64 and a copolymer polyester having an intrinsic viscosity of 0.60 containing 30 mol% of isophthalic acid and 15 mol% of diethylene glycol in a weight ratio of 75:25, this was mixed with trifluoroacetic acid. And a methylene glycol mixed solvent (50:50) to prepare a spinning solution having a solid content of 15% by weight.

<Production Example 3> Manufacture of spinning melt A mixed composition comprising 30 mol% of a polyamide polymer having an average molecular weight and 70 mol% of a polyimide polymer having an average molecular weight is melted at 350 ° C using an electric furnace, and is melted by spinning. The body was manufactured.

<Example 1> Production of nano-sized long fibers 1
As shown in FIG. 1, a spinning solution containing 25% by weight of the polyamide-polyimide copolymer produced in Production Example 1 is injected into the spinning solution injection unit 102, and the spinning solution is discharged at 0.3 mL / min. When supplied to the spinning nozzle 103 at a speed, droplets are generated at the tip of the spinning nozzle having a diameter of 0.42 mm. At this time, when a voltage is applied from the high voltage generator 101 whose critical voltage is set to 1.5 Kv / cm, the liquid droplet is ruptured and rotates at 40 rpm while being perpendicular to the spinning nozzle 103. The nanofibers are collected on the primary disk-shaped collector 104, and then the spinning nanofibers 105 collected on the primary disk-shaped collector 104 are rotated at 20 rpm using a separate charged bar. It was induced to continuously accumulate on a roll collector. At this time, the distance between the spinning nozzle 103 and the primary plate collector 104 was set to 10 cm, and the distance between the primary disc collector 104 and the secondary roll collector 106 was set to 10 cm. When the formed nanofibers were magnified 300 times and 20,000 times with a scanning microscope, it was confirmed that long fibers having an average diameter of 0.4 μm were produced (FIGS. 2 and 3).

<Example 2> Production of nano-sized long fibers 2
A spinning solution containing 25% by weight of the polyamide-polyimide copolymer produced in Production Example 1 is injected into the spinning solution injection unit 102, and the spinning solution is supplied to the spinning nozzle 103 at a discharge rate of 0.3 mL / min. Then, a droplet is generated at the tip of a spinning nozzle having a diameter of 0.42 mm. At this time, when a voltage is applied from the high voltage generator 101 whose critical voltage is set to 1.3 Kv / cm, the droplet is ruptured and rotates horizontally at 40 rpm with respect to the spinning nozzle 103. Nanofibers are collected on the primary disk-shaped collector 104. Next, when the secondary roll-shaped collector 106 is brought close to the primary disk-shaped collector 104 at a distance of about 4 cm, one of the spun nanofibers 105 collected by the primary disk-shaped collector 104 is collected. The parts are collected on the secondary roll collector 106. Thereafter, while the secondary roll collector 106 is separated from the primary disk collector 104 at a distance that does not break the spun nanofiber 105, the secondary roll collector 106 is rotated at 20 to 60 rpm. The nanofiber was manufactured by extruding to the XY axis. At this time, the distance between the spinning nozzle 103 and the primary disk-shaped collector 104 is 4 cm, and the distance between the primary plate-shaped collector 104 and the secondary roll-shaped collector 106 is 10 cm (FIG. 4). When the formed nanofiber was magnified 3000 times with a scanning microscope, it was confirmed that the nanofiber was a long fiber with a mean diameter of 0.8 μm (FIG. 5).

<Example 3> Production of nano-sized long fibers 3
A spinning solution containing 25% by weight of the polyamide-polyimide copolymer produced in Production Example 1 is injected into the spinning solution injection unit 102, and the spinning solution is supplied to the spinning nozzle 103 at a discharge rate of 0.3 mL / min. Then, a droplet is generated at the tip of a spinning nozzle having a diameter of 0.42 mm. Thereafter, electrospinning was performed under the same conditions as in Example 1 except that the treatment as shown in FIG. 6 was performed. A primary plate-like collector 104a made of a metal plate fixed in a vertical direction with respect to the spinning nozzle installed at the upper end, and positioned at an angle of 90 ° with respect to the primary plate-like collector 104a; A separate secondary plate collector 104b separated and fixed at a distance is provided. At this time, the spinning nozzle is charged “+”, the primary plate collector 104a is charged “−”, and the secondary plate collector 104b is not charged. Thereby, the spun nanofiber 105 is collected.

  FIG. 7 shows the result of observing the surface of the nanofiber produced in Example 3 with a scanning microscope, magnified 300 times, and is a nano-sized long fiber with a mean diameter of 1.4 μm and a twist. It was confirmed.

<Example 4> Production of nano-sized long fibers 4
A spinning solution containing 25% by weight of the polyamide-polyimide copolymer produced in Production Example 1 is injected into the spinning solution injection unit 102, and the spinning solution is supplied to the spinning nozzle 103 at a discharge rate of 0.3 mL / min. Then, a droplet is generated at the tip of a spinning nozzle having a diameter of 0.42 mm. Thereafter, electrospinning was performed under the same conditions as in Example 1 except that the treatment as shown in FIG. 8 was performed. A spinning nozzle 103 having a diameter of 0.42 mm was installed at the upper end, and two roll-shaped collectors 106a and 106b were installed at the lower end. The primary collector 106a on which the nanofibers to be spun are accumulated first is in the form of a metallic roll and rotates at 40 rpm. A secondary roll collector 106b that rotates at the same rotational speed as the primary roll collector while maintaining a height difference of 5 to 10 m with respect to the primary roll collector 106a is provided. The secondary roll collector 106b is made of glass that can generate static electricity. At this time, the spinning nozzle 103 was charged to “+”, and the primary roll collector 106a located at the lowermost end was charged to “−”.

  FIG. 9 shows the result of observing the surface of the nanofiber produced in Example 4 with a scanning microscope by magnifying it 50 times, and is a nanosized long fiber with a mean diameter of 5.1 μm and a twist. It was confirmed.

<Example 5> Production of nano-sized long fibers 5
A spinning solution containing 25% by weight of the polyamide-polyimide copolymer produced in Production Example 1 is injected into the spinning solution injection unit 102, and the spinning solution is supplied to the spinning nozzle 103 at a discharge rate of 0.3 mL / min. Then, a droplet is generated at the tip of a spinning nozzle having a diameter of 0.42 mm. Thereafter, electrospinning was performed under the same conditions as in Example 1 except that the treatment as shown in FIG. 10 was performed. A spinning nozzle 103 having a diameter of 0.42 mm is installed at the upper end, and a metallic primary plate collector 104a is fixedly installed at the lower end. The secondary plate collector 104b is at an angle of 90 ° with respect to the plate collector 104a. Was installed. The primary plate collector 104a and the secondary plate collector 104b are L-shaped double collectors made of the same material. The primary plate collector 104a and the secondary plate collector 104b are L-shaped double collectors composed of two plate collectors. The primary plate collector 104a and the secondary plate collector 104b are connected to each other, and an intermediate layer 109 is further provided at the lower end of the secondary plate collector 104b. The intermediate layer 109 uses a non-conductive material to charge the primary collector and the secondary collector independently. At this time, the spinning nozzle 103 was charged to “+”, and the L-shaped double collectors 104a and 104b were charged to “−”.

  FIG. 11 shows the result of enlarging the surface of the nanofiber produced in Example 5 300 times using a scanning microscope, and confirmed that the nanofiber was a nanosized long fiber with a mean diameter of 2.5 μm and a twist. .

<Example 6> Production of nano-sized long fibers 6
A spinning solution containing 25% by weight of the polyamide-polyimide copolymer produced in Production Example 1 is injected into the spinning solution injection unit 102, and the spinning solution is supplied to the spinning nozzle 103 at a discharge rate of 0.3 mL / min. Then, a droplet is generated at the tip of a spinning nozzle having a diameter of 0.42 mm. Thereafter, electrospinning was performed as shown in FIG. A spinning nozzle 103 having a diameter of 0.42 mm is installed at the upper end, and a primary disk-shaped collector 104 is installed in the horizontal direction with respect to the spinning nozzle 103 and rotates at 50 rpm, with respect to the primary disk-shaped collector 104. In the vertical direction, a conveyor belt-like secondary roll collector 106c that can be pulled in an endless track is installed. At this time, the distance between the spinning nozzle 103 and the primary disc-shaped collector 104 is set to 4 cm, the critical voltage is set to 1.3 Kv / cm, the spinning nozzle 103 is charged to “+”, and the primary disc-shaped collector 104 is charged. Electrospun under conditions charged to "-". As a result, fibers were continuously produced.

  FIG. 13 shows the result of enlarging the surface of the nanofiber produced in Example 6 300 times using a scanning microscope, and confirmed that the nanofiber is a nanosized long fiber with a mean diameter of 4.5 μm and a twist. .

<Comparative Example 1> Production of nanofiber A spinning solution containing 25% by weight of the polyamide-polyimide copolymer produced in Production Example 1 was injected into the spinning solution injection part 202, and the critical voltage was set to 1 Kv / cm. When a voltage is applied from the high voltage generator 201, the spinning solution is generated as a droplet at the end of the spinning nozzle 203 and spun. Thereafter, the spun spinning solution was accumulated on a metal mesh plate collector 204 positioned in a direction perpendicular to the spinning nozzle (FIG. 14). When the nanofiber web 207 accumulated on the collector 204 was observed with a scanning microscope by magnifying 300 times, it was found that the nanofiber web 207 was manufactured in the nonwoven fabric shape of FIG. Moreover, when it expanded and observed 20,000 times, it turned out that it comprised from the nanoweb of the average diameter of 0.5 micrometer (FIG. 15). At this time, the nozzle diameter, the distance between the spinning nozzle and the metal collector at the lower end, and the critical voltage were the same as those in Example 1.

  Table 1 shows average diameters and diameter ranges of the nanofibers manufactured in Examples 1 to 6 and the nanofiber manufactured in Comparative Example 1.

  As shown in Table 1, it was confirmed that the fibers produced in Examples 1 to 6 and Comparative Example 1 were nanofibers having a nano-sized diameter range. In particular, it can be seen that the nanofibers manufactured in Examples 1 to 6 can adjust the diameter of the nanofiber according to the critical voltage and the discharge speed at which the spinning solution or the melt is moved to the spinning nozzle. Moreover, although the nanofiber manufactured by the comparative example 1 is a nonwoven fabric form (FIGS. 15 and 16), on the other hand, the nanofiber manufactured by Examples 1-6 is FIG.2, FIG.5, FIG.7, From the results of the scanning microscopes of FIGS. 9, 11 and 13, it was confirmed that the filaments were filament-like (twisted) long fibers.

[Industrial applicability]
As described above, according to the present invention, a filament bundle-like nano-sized long fiber manufactured by an improved electrospinning method has a mechanical property improved compared to a conventional nanofiber nonwoven fabric and has a conventional micron diameter. Alternative use is possible in all fields using fiber. For example, the fiber of the present invention is useful firstly as a medical filter for kidney dialysis and blood purification and various membrane reinforcing materials for gene separation, and secondly, in the electrical and electronic field, an ultra-thin reinforcing plate and It is useful for manufacturing an ultra-thin PCB substrate, and thirdly, it can be applied to an ultra-compact ultralight aircraft or an unmanned adjustment flying robot, and fourthly, it is useful as a reinforcing material for optical cables in the optical communication field.

1 is a first preferred embodiment of an electrospinning method using a multiple collector of the present invention. It is the result of having expanded the surface of the nanofiber manufactured by suitable 1st Embodiment of this invention 300 times using the scanning microscope. It is the result of having expanded the surface of the nanofiber manufactured by suitable 1st Embodiment of this invention 20,000 times using the scanning microscope. It is a second preferred embodiment of the electrospinning method using the multiple collector of the present invention. It is the result of having expanded the surface of the nanofiber manufactured by suitable 2nd Embodiment of this invention 3000 times using the scanning microscope. It is a preferred third embodiment of the electrospinning method using the multiple collector of the present invention. It is the result of having expanded the surface of the nanofiber manufactured by suitable 3rd Embodiment of this invention 300 times using the scanning microscope. It is a preferred fourth embodiment of the electrospinning method using the multiple collector of the present invention. It is the result of enlarging 50 times the surface of the nanofiber manufactured by suitable 4th Embodiment of this invention using the scanning microscope. It is a preferred fifth embodiment of the electrospinning method using the multiple collector of the present invention. It is the result of having magnified 300 times the surface of the nanofiber manufactured by suitable 5th Embodiment of this invention using the scanning microscope. It is a preferred sixth embodiment of the electrospinning method using the multiple collector of the present invention. It is the result of enlarging 300 times the surface of the nanofiber manufactured by suitable 6th Embodiment of this invention using the scanning microscope. It is embodiment of the electrospinning method using the conventional single collector. It is the result of enlarging 300 times the surface of the nanofiber manufactured by the electrospinning method using the conventional single collector using the scanning microscope. It is the result of having magnified the surface of the nanofiber manufactured by the electrospinning method using the conventional single collector 20,000 times using the scanning microscope.

Claims (14)

  A spinning solution produced by dissolving two or more polymer blends or copolymers in a solvent, or a spinning melt produced by melting the polymer is dropped from a spinning nozzle to which a critical voltage is applied. And the spun droplets are continuously collected and produced on a multi-collector having a single shape selected from a plate shape and a roll shape, or a combination thereof. , Nano-sized long fibers in a bundle of filaments.   2. The polymer is a combination of two or more selected from the group consisting of polyimide, polyamide, polyethylene, polypropylene, polyester, vinylidene fluoride resin, polyacrylonitrile, polysulfone, and polyethylene oxide. 2. Filament bundle-like nano-sized long fibers.   2. The filament bundle-like nano-sized long fiber according to claim 1, wherein the polymer includes one or more amine groups selected from the group consisting of monoamine, diamine, triamine, and tetraamine. The polymer is a polyamide-polyimide copolymer composed of a compound represented by the following chemical formula 1 in which m is 10 to 50 mol% and a compound represented by the following chemical formula 2 in which n is 50 to 90 mol%. The filament bundle-like nano-sized long fiber according to claim 1, wherein

  The filament-like nano-sized long fiber according to claim 4, wherein the polyamide-polyimide copolymer has a number average molecular weight of 500 to 1,000,000.   2. The solvent according to claim 1, wherein the solvent is any one selected from the group consisting of N-methyl-2-pyrrolidone, γ-butyrolactone, 2-butoxyethanol, dimethylacetamide, and dimethylformamide. Filament bundle of nano-sized long fibers.   The filament bundle-shaped nano-sized long fiber according to claim 1, wherein the filament bundle-shaped nano fiber is composed of a long fiber having a nano-size having a diameter of 1 to 1000 nm. 1) A spinning solution produced by dissolving 10 to 50% by weight of two or more polymer blends or copolymers in a solvent, or a spinning melt produced by melting the polymer at a temperature higher than the melting temperature. Prepare the body
2) Electrospinning the spinning solution or the spinning melt as droplets from a spinning nozzle to which a critical voltage is applied,
3) After discharging the spun droplets onto the primary collector to form nanofibers, the nanofibers collected on the primary collector are collected again on the secondary collector and continuously accumulated. However, at this time, at least one of the collectors rotates, and the method for producing filament bundles of nano-sized long fibers.   The method for producing filament bundle nano-sized long fibers according to claim 8, further comprising one or more collectors in addition to the primary collector and the secondary collector.   [9] The filament bundle of nano-sized filament bundle according to claim 8, wherein the primary collector is a metal plate or metal mesh made of an electrically conductive material, and is fixed or rotated at 1 to 1000 rpm. A method for producing long fibers.   [9] The filament bundle according to claim 8, wherein the secondary collector is a glass or plastic tube or rod made of a material capable of generating static electricity, or a tube or rod coated with the material. A method for producing nano-sized long fibers.   The method for producing filament bundle-shaped nano-sized long fibers according to claim 8, wherein the secondary collector has a roll shape rotating at 1 to 100 rpm.   The method for producing a filament bundle-shaped nano-sized long fiber according to claim 8, wherein a distance between the spinning nozzle and the primary collector is 1 to 50 cm.   The method for producing filament bundle-shaped nano-sized long fibers according to claim 8, wherein a distance between the primary collector and the secondary collector is 1 to 50 cm.

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