KR100696285B1 - Method of manufacturing continuous high strength filament composed of nanofibers and filaments manufactured thereby - Google Patents

Abstract

The present invention relates to a method for producing a continuous phase high-strength filament composed of nanofibers and a filament produced therefrom, wherein the method for producing a polymer spinning solution has a unit width (u) of 1 to 100 mm through a nozzle (5). Electrospinning on one or two or more band-shaped collectors 7 with a rotational speed of 5 m / sec or more to produce a ribbon-shaped nanofiber web 14a, followed by nanofibers produced by the concentrator 16 The twisting of the web 14a or the nanofibers constituting the nanofiber web 14a are entangled with each other to produce a continuous filament 14b made of nanofibers, and then wound.

The filament produced by the present invention is composed of nanofibers, the nanofibers are oriented less than 10 ° with respect to the fiber axis direction, the tensile strength is more than 100MPa.

The present invention can produce a high strength continuous phase filament (thread) composed of nanofibers by an electrospinning method in a simple and continuous process.

Nanofiber, filament, yarn, electrospinning, band collector, high strength.

Description

Method of manufacturing continuous high strength filaments composed of nanofibers and filaments produced therefrom {Method of manufacturing continuous high strength filament composed of nanofibers and filaments manufactured}

1 is a process schematic diagram of the present invention.

FIG. 2 is an enlarged schematic view of a portion of the band collector 7 in FIG. 1. FIG.

Fig. 3 is a schematic diagram showing a form in which the nozzles 5 are arranged in three rows on the nozzle block 4 in the rotation direction of the band collector 7.

Figure 4 is a process schematic diagram of the present invention for producing a nanofiber filament of the hybrid (Hybrid) form.

5 is a schematic view of the nozzle block 4 used in the bottom-up electrospinning method.

Figure 6 (a) is a cross-sectional view of the spinning solution drop device 3 used in the bottom-up electrospinning method.

Figure 6 (b) is a perspective view of the spinning solution drop device 3 used in the bottom-up electrospinning method.

Figure 7 is an electron microscope photograph of the surface of the nanofiber filament prepared in Example 1.

※ Explanation of main parts in drawings

1: Spinning solution main tank 2: Metering pump 3: Spinning solution drop device

3a: filter of spinning solution drop device 3b: gas inlet pipe 3c: spinning solution induction pipe

3d: spinning solution discharge pipe 4: nozzle block 4b: nozzle outer diameter hole

4c: insulator plate 4d: spinning solution temporary supply plate 4e: nozzle plate

4f: Spinning solution main supply plate 4g: Heating device 4h: Conductor plate

5: nozzle 6: nanofiber 7: band type collector

7b: non-conductive barrier

8a, 8b: collector rotary roller

9: voltage generator

10: nozzle block left and right reciprocating device 11a: motor for the stirrer 11c

11b: non-conductive insulation rod 11c: agitator 12: spinning solution discharge device

13: transfer tube 14a: web composed of nanofibers

14b: filaments composed of nanofibers

15a, 15b: feed roller 16: focusing device

17: filament winding roller

u: unit width of the band collector 7

θ: angle formed between the center line of the nozzle and the horizontal direction of the band collector (nozzle angle)

The present invention relates to a method for producing a continuous phase high-strength filament or yarn (hereinafter referred to as "filament") composed of nanofibers, and a filament produced therefrom, and more specifically, a continuous phase filament using an electrospinning method It relates to a method for producing the in a continuous process.

In the present invention, the nanofiber means a fiber having a fiber diameter of 1,000 nm or less, more preferably 500 nm or less.

Non-woven fabrics composed of nanofibers can be used in various ways such as artificial leather, filters, diapers, sanitary napkins, sutures, anti-adhesion agents, wiping cloths, artificial blood vessels, bone fixing devices, etc. useful.

Conventional techniques for producing ultrafine fibers or nanofibers suitable for the manufacture of artificial leather and the like are known as island-in-the-sea composite spinning, split composite spinning and blend spinning.

However, in the case of island-in-the-sea composite spinning or blend spinning, one of the two polymer components constituting the fibers must be eluted and removed for the finer fibers. In order to manufacture, there has been a problem of undergoing complex processes such as melt spinning, fiber manufacturing, nonwoven fabric production, urethane impregnation, and one component elution. Nevertheless, the two methods could not produce fibers with a diameter of 1,000 nm or less.

On the other hand, in the split type composite spinning method, two polymer components having different dyeing characteristics (for example, polyester and polyamide) coexist in the fiber, so that a dyeing band appears, and the artificial leather manufacturing process has a complicated problem. In addition, it was difficult to produce fibers with a diameter of 2,000 nm or less by the above method.

As another conventional technique for manufacturing nanofibers, US Patent No. 4,323,525 et al. Proposes an electrospinning method. The conventional electrospinning method continuously supplies the polymer spinning liquid in the spinning liquid main tank into a plurality of nozzles to which a high voltage is applied through a metering pump, and continuously supplies the spinning liquid supplied to the nozzle to a high 5 kV or more through the nozzle. A fiber web is manufactured by spinning and focusing on an endless belt type focusing device under voltage. The fiber web thus prepared is needle punched in the following process to produce a nonwoven fabric composed of nanofibers.

As described above, the conventional electrospinning method may produce only a web (WEB) and a nonwoven fabric made of nanofibers of 1,000 nm or less. Therefore, in order to manufacture a continuous filament by the conventional electrospinning method, the prepared nanofiber web is cut to a predetermined length to produce short fibers, and the surface is mixed again to undergo a separate spinning process, thereby causing a complicated process.

In the case of nonwoven fabric composed of nanofibers, due to the inherent limitations in the properties of the nonwoven fabric, there was a limitation in applying it to various applications such as artificial leather. For reference, in the case of a nonwoven fabric composed of nanofibers, it is difficult to achieve physical properties of 10 MPa or more.

The present invention provides a method of continuously producing high strength filaments (threads) using an electrospun nanofiber web without a separate spinning process, and intends to manufacture a continuous filament made of nanofibers in a simple process. The present invention improves the properties of the continuous filament by electrospinning the polymer spinning solution on the band-shaped collector 7 rotating at a speed of 5 m / sec or more so that the electrospun nanofibers are oriented at 10 ° or less in the fiber axis direction. We want to provide a way to do this.

The method for producing a continuous phase high strength filament composed of the nanofibers of the present invention for achieving the above problems, the polymer spinning solution through the nozzle (5) unit width (u) of 1 ~ 100mm and a rotational speed of 5m / sec Electrospinning on one or more band-shaped collectors 7 or more to produce ribbon-shaped nanofiber webs 14a, and then twisting the nanofiber webs 14a produced by the focusing device 16 It is characterized in that the nanofibers constituting the nanofiber web (14a) or by interlacing each other to produce a continuous filament (14b) consisting of nanofibers, and then wound it do.

In addition, the continuous high-strength filament of the present invention produced by the above method is composed of nanofibers, characterized in that the nanofibers are oriented less than 10 ° with respect to the fiber axis direction.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, the present invention is a polymer spinning solution as shown in Figure 1 and 2 through the nozzle (5) unit width (u) of 1 ~ 100mm and the rotation speed of one or two or more band type of 5m / sec or more Electrospinning to the collector 7 of the to form a ribbon-shaped nanofiber web (14a). 1 is a process schematic diagram of the present invention. When the unit width u of the band-type collector 7 exceeds 100 mm, the width of the manufactured nanofiber web 14a is very large, making it difficult to form a filament form, and the band-type collector 7 at high speed. It is very difficult to rotate. On the other hand, when the unit width u of the band-shaped collector 7 is less than 1 mm, the amount of the electrospun nanofibers is very small, making it difficult to manufacture the filament at high speed. More preferably, the unit width u of the band collector 7 is 5 to 60 mm.

In the present invention, only one band-type collector 7 may be used or two or more of them may be used in combination.

When the band-type collector 7 is used in combination, a non-conductive blocking film 7b is provided between the band-type collectors 7 as shown in FIG. 2 to distinguish them.

Fig. 2 is an enlarged schematic view of a portion of the band-shaped collector 7 showing that the band-shaped collectors 7 are combined and used in a state separated by the non-conductive blocking film 7b.

Further, the nozzles 5 and the nozzle blocks 4 are located at the bottom of the band-shaped collector 7 as shown in Fig. 1, which is advantageous for arranging the nozzles more in the traveling direction of the nanofiber web 14a. Do.

In general, when electrospinning with a polymer solution, the distance between the nozzle and the collector (radiation distance) is very short (less than 30 cm). Therefore, it is very difficult to install the stretching roller between this nozzle and the collector. In addition, general electrospun webs or filaments are not arranged in the direction of the fiber axis has very low physical properties. In order to orient the nanofibers electrospun in the fiber axis direction, the only method using centrifugal force or air or the like is used. Accordingly, in the present invention, the nanofibers are oriented in the fiber axis direction by using the centrifugal force of the rotating collector 7 and the flow of air generated at this time.

In the present invention, the nanofibers electrospun in the machine direction (rotation direction) of the band-shaped collector 7 rotating at high speed are arranged side by side. In the nozzle block 4, the nozzles 5 are arranged in one row or more.

Figure 3 is a schematic diagram showing that the nozzles are arranged in the rotation direction of the band collector in three rows in the nozzle block. The row of nozzles located in the middle are arranged in the vertical direction of the band-type collector, and the two nozzles located on both sides show that the horizontal direction of the band-type collector and the central axis of the nozzle are arranged at an angle of θ. In order to increase the amount of nanofibers electrospun in unit time, it is advantageous to use a nozzle block in which nozzles are arranged in a plurality of rows.

On the other hand, in order to easily separate the nanofiber web 14a formed on the surface of the band-shaped collector 7 of the present invention from the band-type collector 7, the solution for separating the nanofiber web on the band-type collector 7 is continuously Or coating or spraying discontinuously.

The nanofiber web separation solution is water, an organic solvent, a cationic surfactant, an anionic surfactant, an amphoteric (cationic-anionic) surfactant or a neutral surfactant. Ethanol, methanol, benzene, methylene chloride, toluene and the like are used as the organic solvent.

The bottom-up spinning apparatus shown in FIG. 1 is combined with a spinning solution main tank 1 for storing spinning solution, a metering pump 2 for metering spinning solution, and a nozzle 5 composed of a plurality of pins in a block form. And a bottom-up nozzle block 4 for discharging the spinning liquid into a fiber, a band-shaped collector 7 for accumulating short fibers disposed on the nozzle block, a voltage generator 19a for generating a high voltage, and a nozzle block. And a spinning solution discharge device 12 connected to the top.

As shown in FIG. 5, the nozzle block 4 includes a nozzle plate 4e in which the nozzle [5] is arranged, [ii] an nozzle outer diameter hole 4b surrounding the nozzle 5, and a nozzle outer diameter hole. (4b) and [9] the insulator plate (4c) and [ⅴ] nozzles provided at the upper end of the spinning solution temporary supply plate (4d) and [i] the spinning solution temporary supply plate (4d). In the same manner as the arrangement, the pins are arranged and the conductive plate 4h is located directly below the nozzle plate 4e, and the radiant solution main supply plate 4f is located directly below the conductive plate 4h. And a heating device 4g located directly below the spinning solution main supply plate 4f, and an agitator 11c provided inside the spinning solution main supply plate 4f.

The nozzles 5 in the nozzle block 4 are arranged in the nozzle plate 4e, and the nozzle outer diameter holes 4b surrounding the nozzles 5 are provided on the outside of the nozzle 5.

The nozzle outer diameter hole (4b) is installed to prevent the droplet (droplet) phenomenon generated when all the spinning solution formed in excess at the nozzle (5) can not be fiberized and to recover the overflow spinning solution, nozzle exit Collects the spinning solution that has not been fiberized in and serves to transfer it to the spinning solution temporary supply pipe (4d) located directly on the top of the nozzle plate (4e).

The nozzle outer diameter hole 4b is, of course, larger in diameter than the nozzle 5 and is preferably composed of an insulator.

The spinning solution temporary supply plate 4d is made of an insulator and temporarily stores the remaining spinning solution flowing through the nozzle outer diameter hole 4b and then transfers it to the spinning solution main supply plate 4f.

An insulator plate 4c is installed at the upper end of the spinning solution temporary supply plate 4d to protect the top of the nozzle so that radiation can be smoothly only at the nozzle area.

Directly below the nozzle plate 4e, a conductor plate 4h in which pins are arranged in the same manner as the nozzle array is provided, and a spinning solution main supply plate 4f including the conductor plate 4h is provided.

In addition, an indirect heating type heating device 4g is installed directly below the spinning solution main supply plate 4f.

The conductor plate 4h serves to apply a high voltage to the nozzle 5, and the spinning solution main supply plate 4f stores the spinning solution flowing into the spinning block 4 from the spinning drop device 3 and then nozzles. We play role to supply in (5). At this time, the spinning solution main supply pipe (4f) is preferably made of a minimum space to minimize the storage of the spinning solution.

On the other hand, the spinning solution drop device (3) is designed to have a closed cylindrical shape as shown in Figure 6 (a) and Figure 6 (b) as a whole flowing continuously from the spinning solution main tank (1) It serves to supply the spinning solution to the nozzle block (4) in the form of a drop.

The spinning solution drop device 3 has a cylindrical shape as a whole, as shown in Figs. 6 (a) to 6 (b). Figure 6 (a) is a cross-sectional view of the spinning solution drop device, Figure 6 (b) is a perspective view of the spinning solution drop device. On the upper end of the spinning solution dropping device 3, a spinning solution induction pipe 3c and a gas inlet pipe 3b for guiding the spinning solution toward the nozzle block are arranged side by side. At this time, it is preferable to form the spinning solution induction pipe (3c) slightly longer than the gas inlet pipe (3b).

Gas is introduced from the lower end of the gas inlet pipe, the first gas is introduced portion is connected to the filter (3d). At the lower end of the spinning solution dropping device 3, a spinning solution discharge pipe 3d for guiding the dropped spinning solution to the nozzle block 4 is formed. The middle portion of the spinning solution drop device 3 is formed in a hollow state so that the spinning solution can be dropped at the distal end of the spinning solution induction pipe 3c.

The spinning solution introduced into the spinning solution drop device 3 flows down along the spinning solution induction tube 3c and is dropped at its distal end to block the flow of the spinning solution more than once.

Looking at the principle that the spinning solution is dropped in detail, when the gas enters the upper end of the sealed spinning solution drop device 3 along the filter 3d and the gas inlet pipe 3b, the spinning solution is induced by gas vortex, etc. The pressure in the tube 3c becomes naturally irregular, and the spinning solution drops due to the pressure difference generated at this time.

As the gas introduced in the present invention, an inert gas such as air or nitrogen may be used.

The entire nozzle block 4 reciprocates left and right in a direction perpendicular to the traveling direction of the nanofibers electrospun by the nozzle block left and right reciprocating device 10 in order to uniformize the distribution of the electrospun nanofibers.

Further, inside the nozzle block 4, more specifically, inside the spinning solution main supply plate 4f, the spinning solution is stored in the nozzle block 4 to prevent gelation of the spinning solution in the nozzle block 4. The stirrer 11c which stirs a spinning solution is provided.

The stirrer 11c is connected to the stirrer motor 11a by a non-conductive insulating rod 11b.

Installing the stirrer 11c in the nozzle block 4 effectively prevents gelation of the spinning solution in the nozzle block 4 when electrospinning a solution containing an inorganic metal or electrospinning a spinning solution dissolved using a mixed solvent for a long time. can do.

In addition, the top of the nozzle block 4 is connected to the spinning solution discharge device 12 for forcibly transferring the spinning solution over-supplied to the nozzle block to the spinning solution main tank (1).

The spinning solution discharge device 12 forcibly transfers the spinning solution oversupplied into the nozzle block to the spinning solution main tank 1 by suction air or the like.

In addition, the collector 7 of the present invention may be provided (attached) a heating device (not shown) of the direct heating method or the indirect heating method.

The nozzles 5 located on the nozzle block 4 are arranged diagonally or in a straight line.

Next, the nanofiber web 14a is twisted or the nanofiber web 14a is continuously passed through the ribbon-shaped nanofiber web 14a formed on the band-shaped collector 7 as described above. The nanofibers constituting the 14a are entangled with each other to produce a continuous filament 14b composed of nanofibers, and then wound up in a winder 17.

The focusing device 16 is an air twist device, an air entanglement device or a disk type entrainment device.

The continuous filament 14b composed of nanofibers may be stretched before being wound, heat treated, or heat treated after stretching.

Meanwhile, two or more band-shaped collectors 7 are electrospun with polymer spinning solutions having different polymer types or concentrations, thereby producing two or more ribbon-shaped nanofiber webs 14a different from each other, and then all of them are one focused. Hybrid filaments may also be produced by passing into the device 16.

Also, as shown in FIG. 4, two or more different types of polymer spinning solutions A and B are supplied to each nozzle block by using two or more nozzle blocks and two or more collectors 7. The ribbon-like nanofiber webs 14a may be made, and then all of them may be passed into one concentrator 16 to produce a hybrid filament.

Figure 4 is a schematic view of the manufacturing process of the present invention for producing a hybrid filament, the reference numerals are omitted in the figure.

When the nanofiber filament is a hybrid (Hybrid) form, there is an advantage that can give a variety of physical properties to the filament.

The continuous high-strength filament manufactured by the manufacturing method of the present invention described above is composed of nanofibers, the nanofibers are oriented at 10 ° or less or 5 ° or less with respect to the fiber axis direction, and the tensile strength is 100 MPa or more. .

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited by the following examples.

Example 1

A polymer spinning solution was prepared by dissolving a nylon 6 resin having a relative viscosity of 3.2 in 96% sulfuric acid at a concentration of 15% by weight in formic acid. The surface tension of the polymer spinning solution was 49 mN / m, the solution viscosity was 1150 centipoise at room temperature, and the electrical conductivity was 420 mS / m.

The polymer spinning solution is rotated at a speed of 10 mm / sec with a unit width u of 15 mm through a nozzle block 4 in which nozzles having a diameter of 1 mm are arranged in a line through a metering pump 2 as shown in FIG. 1. It was electrospun with four band-type collectors 7. Four band-type collectors 7 were used in combination with each other by the Teflon blocking films 7b.

The band collector 7 is installed above the nozzle block 4. In the nozzle block 4, nozzles were arranged in three rows as shown in FIG. The center row was arranged in the vertical direction of the band collector, and the two rows of nozzles located on both sides were arranged so that the angle θ formed between the center axis of the nozzle and the horizontal axis of the band collector was 45 °. The nozzles in the nozzle block were arranged with 500 nozzles in each row and electrospinning using a total of 1,500 nozzles.

In addition, the voltage at the time of electrospinning was 30 kV, and the radiation distance was 15 cm.

Subsequently, the air twist device (concentrator 16) having an air pressure of 3 kg / cm 2 while transferring the nanofiber web 14a manufactured as described above to the web feed rollers 15a and 15b having a linear linear speed of 600 m / min. After imparting twist to the nanofiber web, it was wound up in the winder 17.

The nanofiber filaments prepared as described above had a fineness of 27 denier, a strength of 150 MPa, an elongation of 27%, and an orientation angle of the nanofibers with respect to the fiber axis was 1.4 °.

In addition, an electron micrograph of the surface of the prepared nanofiber filament is as shown in FIG.

The present invention can produce a continuous phase high-strength filament composed of nanofibers in a simpler continuous process. Continuous filament filaments produced by the present invention is the nanofibers constituting the oriented nanofibers are oriented less than 10 ° with respect to the fiber axis direction is greatly improved physical properties. Therefore, the continuous high-strength filament of the present invention can be used in various industries such as artificial leather, air cleaning filters, wiping cloth, golf gloves, wigs, as well as artificial dialysis filters, artificial blood vessels, antiadhesion agents, artificial bones, and the like. Useful as a field material.

Claims (11)

A ribbon-shaped nanofiber web is electrospun through the nozzle 5 with a unit width (u) of 1 to 100 mm and a rotational speed of 5 m / sec or more on one or two band collectors (7). (14a), and then a continuous phase composed of nanofibers by twisting the nanofiber webs 14a produced by the focusing device 16 or by intertwining the nanofibers constituting the nanofiber webs 14a with each other. Method for producing a continuous phase high-strength filament consisting of nanofibers, characterized in that after producing the filament (14b). The method for producing a continuous phase high strength filament made of nanofibers according to claim 1, wherein the continuous phase filaments (14b) composed of nanofibers are stretched before being wound, heat treated, or heat treated after stretching. 2. A method according to claim 1, characterized in that the two or more band-type collectors (7) are separated by a barrier film (7b) which is a non-conductor. The method of manufacturing a continuous phase high-strength filament made of nanofibers according to claim 1, wherein the band-shaped collector (7) has a unit width (u) of 5 to 60 mm. Method according to claim 1, characterized in that the nozzle (5) is located below the band-shaped collector (7). The method of claim 1, wherein the nanofibers are continuously or discontinuously coated or sprayed with a solution for separating nanofiber webs on the band-shaped collector 7 to be electrospun. Way. The continuous phase solid composition of nanofibers according to claim 6, wherein the solution for separating the nanofiber web is water, an organic solvent, a cationic surfactant, an anionic surfactant, an amphoteric (cationic-anionic) surfactant or a neutral surfactant. Method for producing strong filaments. 2. The two or more band-shaped collectors 7 are electrospun with different polymer spinning solutions to produce two or more different ribbon-like nanofiber webs 14a, and then all of them are one focusing device. (16) A method for producing a continuous phase high strength filament composed of nanofibers, characterized by passing through. A continuous phase high strength filament made of the method of any one of claims 1 to 8, comprising nanofibers, wherein the nanofibers are oriented at 10 ° or less with respect to the fiber axis direction. A continuous high strength filament manufactured by the method of claim 1, wherein the nanofibers are oriented at 5 ° or less with respect to the fiber axis direction. The continuous phase high strength filament manufactured by the method of claim 1, wherein the tensile strength of the continuous phase high strength filament is 100 MPa or more.

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