KR20060071530A - Apparatus of melt electrospinning of pitch and spinning method thereby - Google Patents

Abstract

The present invention relates to a molten electrospinning apparatus and a spinning method of the pitch, and more particularly to a reaction tank having a spin hole of 0.1 to 3mm diameter in order to melt and spin the pitch, a heater for heating the reactor, spun fibers Pitch of roller consisting of focusing roller and roller driving device for focusing, high voltage generator for applying high voltage, high voltage transformer for shielding power part of reactor heater and heater applying high voltage, temperature controller, inert gas supply equipment, etc. Provided are a melt electrospinning apparatus and a melt electrospinning method using the same.

By using the apparatus of the present invention, it is possible to produce fine fibers by electrospinning the pitch directly in the molten state without using a solvent, so that all kinds of pitch including the high softening point pitch are used as raw materials, compared to conventional molten spinning fibers. It can be applied to the production of pitch fibers having a fine diameter, it is possible to produce a variety of functional fibrous carbon material by further heat treatment of the fine pitch fibers prepared as described above.

Pitch, melt electrospinning, spinning device, carbon fiber

Description

Pitch melt electrospinning apparatus and its spinning method {APPARATUS OF MELT ELECTROSPINNING OF PITCH AND SPINNING METHOD THEREBY}

1 shows a preferred pitch melt electrospinning device in accordance with the present invention;

* Description of the symbols for the main parts of the drawings *

1: AC power supply 2: temperature controller

3: high voltage transformer 4: temperature indicator

5: manometer 6: burner

7: pitch reactor 8: inert gas

9: high voltage generator 10: winding machine

The present invention relates to a molten electrospinning apparatus for pitch and a spinning method thereof, and more particularly, a reactor having a spin hole of 0.1 to 3mm diameter to melt and spin the pitch, a heater for heating the reactor, spun fiber Winding machine consisting of concentrating roller and roller driving device for condensing, high voltage generator for applying high voltage, high voltage transformer for shielding the power supply of reactor heater and heater that apply high voltage, temperature controller, inert gas supply equipment There is provided a molten electrospinning apparatus of pitch, and the like, and relates to a manufacturing method for producing pitch fibers having a finer fiber diameter than the conventional melt spinning method of the pitch by such a molten electrospinning apparatus.

The pitch is generally spun by melt spinning, melt blowing, centrifugal spinning, and the like, and the diameter of the fiber produced is 10 μm or less.

However, in order to be used as a raw material of various functional carbon materials, pitch fibers having a smaller diameter are required. For this purpose, an electrospinning method, which is generally used for the electrospinning method of polymers, has been attempted to be applied to the production of pitch fibers.

Korean Patent Application No. 2003-0002759 discloses a method for producing a pitch-based nanocarbon fiber by such an electrospinning method and discloses a method of spinning by applying a high voltage after dissolving the pitch by a solvent.

In addition, 2003-0018056 discloses a method of electrospinning a pitch in which carbon nanofibers are dispersed. In addition, as in 2003-0002759, a method of applying a high voltage after dissolving a pitch by a solvent is disclosed.

However, in the case of using pitch as a raw material of carbonaceous material, in the existing patent, the pitch is dissolved in a solvent such as tetrahydrofuran (THF) to volatilize the solvent by electrospinning. It does not dissolve in solvents, and when only the dissolved part is extracted and spun, the spun fibers have a low softening point, and thus their use is very limited.

In addition, in the case of anisotropic mesophase pitch, electrospinning is impossible by the above method because it is not dissolved in the strongest solvent such as quinoline or pyridine.

Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to propose a method for spinning by applying a high voltage directly in the molten state to enable the production of fine fibers, further All kinds of pitches including high softening point pitch are used as raw materials, so that they can be applied to the production of pitch fibers having a finer diameter than conventional molten spinning fibers. It is possible to manufacture a functional fibrous carbon material.

In order to achieve the above object, a pitch molten electrospinning apparatus provided by the present invention comprises a pitch reactor having a radial hole and a nozzle of a predetermined diameter; and a heater for heating the pitch reactor; and the temperature of the heater A temperature controller for adjusting; and a focusing roller for focusing the fibers radiated through the nozzle;

A high voltage generator for applying a direct current having a predetermined voltage level to the pitch reactor and the focusing roller; And a high voltage transformer disposed between the regulator and the heater of the heater to shield the high voltage applied to the pitch reactor from being transmitted to the regulator of the heater.

Preferably, the pitch reaction tank is provided with a non-contact temperature measuring sensor or a temperature measuring sensor which is not influenced by a high voltage DC voltage, and configured to measure the temperature of the molten pitch, and supplies an inert gas to supply the inert gas to the pitch reaction tank. Further equipment is provided to control the amount of pitch discharged by maintaining an appropriate pressure while preventing the viscosity from being oxidized while the pitch is molten.

In addition, the molten electrospinning method of the pitch according to the present invention, the step of maintaining the pitch in the pitch reaction tank at a temperature higher by 0 ~ 70 ℃ than the softening point; and,

Melt electrospinning of the pitch is achieved by maintaining a distance between the spinneret of the pitch reactor and the focusing roller that focuses the spun fibers by a predetermined distance to spin in a state where a predetermined voltage is applied. The distance between the nozzle and the focusing roller is preferably spaced apart by 2 to 40 cm, and the predetermined voltage is preferably provided with a DC voltage of 5 to 100 kV.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, and in the following description of the present invention, specific descriptions of related well-known functions or configurations may unnecessarily obscure the subject matter of the present invention. If so, the detailed description thereof will be omitted.

According to FIG. 1 showing a preferred pitch melt electrospinning device according to the present invention, the pitch reactor 7 of reference numeral 7 is a pitch reactor 7 having a spin hole of 0.1 to 3 mm in diameter to melt and spin the pitch. It should be able to be adjusted up to 70 ℃ higher than the softening point of pitch, and if necessary, a device such as a stirrer may be added.The material is made of metal in terms of convenience in manufacturing or various aspects, but it is advantageous at the required temperature. As long as it is not deformed, it can be used regardless of ceramic products or other materials.

However, when using a material that does not have electrical conductivity in the pitch reactor (7) should be configured to contact one electrode for applying a high voltage direct current in the pitch.

If the size of the spinning hole is 0.1mm or less, it is difficult to discharge the pitch, and if it is 3mm or more, the pitch is leaked by itself even if the viscosity is low.

The heater 6 of FIG. 6 is a heater for heating the reaction tank, but a conventional heater may be used. However, when the pitch reaction tank 7 is made of an electrically conductive material such as metal, the energization part of the heater and the pitch reaction tank 7 ) Shall be shielded using a method of embedding in an insulating material appropriately so as not to be in direct contact.

Reference numeral 10 is a focusing roller 10 for focusing the spun fiber, it is possible to use a conductive metal or metal plated roller, and if necessary, if the rotational speed of the roller can be adjusted can be adjusted the diameter of the fiber produced Therefore, it is more preferable.

The other pole of the high voltage DC current should be continuously applied to the focusing roller 10 by means of a brush or a bearing. However, it is necessary to use such a rotating roller to manufacture a nonwoven fabric pitch fiber. If necessary, radiation can also be achieved by laminating a thin layer of insulator on the surface of a metal plate applied to one pole of voltage, a conductive material of a particular shape, or a conductive material applied to voltage.

Reference numeral 9 is a high voltage generator (9) of direct current for applying a high voltage, and may be made to apply a direct current of up to 100 kV between the pitch reaction tank (7) or the pitch and the focusing roller (10), the fiber of In order to adjust the characteristics, it is desirable to be manufactured to adjust the voltage.

In the high voltage transformer 3 of FIG. 3, when a high voltage is applied to the pitch reactor 7, a high voltage is induced even in a heater 6 located close to the heater 6, but the regulator 2 of the heater As a high voltage transformer for shielding the transfer of high voltage between power supply parts, it is preferable that the voltages of the primary side and the secondary side are the same, and when the voltage is changed at a specific ratio, the controller can be used by configuring the controller to be suitable for this.

The high voltage DC current applied to the pitch reactor 7 or induced by the heater 6 is not flowed back to the regulator by this apparatus, so that the temperature of the heater 6 can be smoothly controlled.

In addition, reference numerals 2 and 4 of FIG. 1 are a temperature controller 2 and a temperature measuring sensor 4, respectively. The temperature controller 2 may be a conventional one, but in the case of the temperature measuring sensor 4, a high voltage DC voltage is induced. Therefore, it is preferable to use a temperature measuring sensor that is not affected by high voltage or to use an infrared type non-contact temperature sensor as shown in FIG. 4-1.

Reference numeral 8 is a facility for supplying an inert gas to prevent the oxidized while the pitch is melted to increase the viscosity and to control the amount of pitch discharged by maintaining an appropriate pressure.

The method of spinning fine pitch fibers using the molten electrospinning apparatus 100 of the pitch is as follows.

The pitch temperature of the pitch is maintained at a temperature higher by 0 to 70 ℃ than the softening point, and the pitch between the nozzle 11 and the focusing roller 10 is applied to a DC voltage of 5 to 100 kV in a range of 2 to 40 cm to produce pitch fibers. .

The spinning temperature of the pitch is 0 ~ 70 ℃ higher than the softening point, but if it is lower than the softening point, it is impossible to spin because the viscosity is too high. If it is maintained at a temperature above 70 ℃ above the softening point, It is impossible to radiate into the furnace, it is sprayed in the form of beads, and there is a risk of softening point or coking while waiting in the reactor, and volatiles are generated to increase the pressure in the reactor, making it difficult to control the discharge amount. do.

In addition, it is preferable to maintain the distance between the nozzle 11 and the focusing roller 10 in the range of 2 to 40 cm. If the distance is kept below 2 cm, arc discharge may occur between the electrodes. In this case, even if a high voltage of 100 kV or more is applied, the electrostatic attraction is too low, making radiation difficult.

The applied DC voltage is preferably in the range of 5 ~ 100kV. In case of 5kV or less, electrostatic attraction is too low, so radiation is not achieved. It is desirable to derive the most appropriate conditions in the above range because the configuration is more difficult and there is less change in the characteristics of the manufactured product compared to the difficulty of applying high voltage.

Hereinafter, preferred examples are provided to aid in understanding the present invention. However, the following examples are provided only to more easily understand the present invention, and the present invention is not limited to the following examples.

(Example 1)

The petroleum-based isotropic pitch of softening point 260 ° C. constitutes the device 100 of FIG. 1 as described above, and maintains the distance between the nozzle 11 and the focusing roller 10 at 15 cm at 300 ° C. and applies a DC voltage of 40 kV. Spinning.

At this time, the diameter of the spinning nozzle was 0.4mm. As a result, a pitch fiber having a diameter of 2 ~ 10㎛ was prepared.

(Example 2)

The same isotropic pitch as in Example 1 was used to maintain 15 cm at 300 ° C. in a device having a nozzle diameter of 0.4 mm as shown in FIG. 1, and radiated by applying a DC voltage of 60 kV. As a result, a pitch fiber having a diameter of 2 ~ 5㎛ was prepared.

(Example 3)

By using the same isotropic pitch as in Example 1 in the apparatus having a nozzle diameter of 0.4mm as shown in Figure 1 was maintained at 290 ℃ 12cm and radiated by applying a direct current voltage of 50kV. As a result, a pitch fiber having a diameter of about 3㎛ was prepared and the diameter of the finest fiber was about 1㎛.

(Comparative Example 1)

Using the same isotropic pitch as in Example 1, 12cm was maintained at 340 ° C. in a device having a nozzle diameter of 0.4 mm as shown in FIG. 1 and radiated by applying a direct current voltage of 50 kV. As a result, a fine disk-shaped pitch was obtained, and no fibrous form was found.

Although the preferred embodiment of the present invention has been described in detail as described above, those skilled in the art will be able to modify or change the present invention as many as possible without departing from the spirit and scope of the present invention. It will be appreciated that the true technical protection scope of the present invention should be defined in the claims.

By using the molten electrospinning apparatus according to the present invention, it is possible to produce fine fibers by electrospinning the pitch directly without using a solvent, so that all kinds of pitches are used as raw materials, including high softening point pitch. Compared to the spinning fiber, there is an effect that can be applied to the production of pitch fibers having a fine diameter.

Then, by further heat treatment of the fine pitch fibers prepared as described above there is an effect that can be produced a variety of functional fibrous carbon material.

Claims (5)

A pitch reactor having a spinning hole and a nozzle having a predetermined diameter; A heater for heating the pitch reactor; A temperature controller for controlling the temperature of the heater; A focusing roller for focusing the fibers spun through the nozzle; A high voltage generator for applying a direct current having a predetermined voltage level to the pitch reactor and the focusing roller; And A molten electrospinning device of a pitch, comprising: a high voltage transformer disposed between the heater and the heater so as to shield the high voltage applied to the pitch reactor from being transferred to the heater of the heater. The method of claim 1, The pitch reaction tank is electroless electrospinning apparatus, characterized in that the non-contact temperature measuring sensor is provided. The method of claim 1, An inert gas supplying device for supplying an inert gas to the pitch reaction tank is further provided. The method of claim 1, A pitch-molded electrospinning apparatus using a material in which an insulator layer is laminated on a surface of a conductive material applied with one pole of voltage or a conductive material with one pole of voltage instead of the focusing roller. Maintaining the pitch in the pitch reactor at a temperature higher by 0 to 70 ° C. than the softening point; and, Pitch molten electrospinning method of maintaining the distance between the spinning nozzle of the pitch reactor and the focusing roller for focusing the spun fibers by 2 to 40cm to be spun in the state of 5 to 100kV DC voltage applied.

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