KR101424883B1 - Method for preparing electrically conductive hollow fiber and electrically conductive hollow fiber prepared thereby - Google Patents

Abstract

The present invention provides a method for preparing a thermoplastic polymer master batch, comprising: preparing a thermoplastic polymer master batch chip comprising 5 to 10% by weight of a fluidized-bed carbon nanotube; Radiating the thermoplastic polymer using a hollow spinning nozzle having a cross-sectional shape including an air layer; And cooling after spinning. According to the present invention, a conductive hollow fiber having excellent conductivity can be produced by a simple process.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method for producing a conductive hollow fiber, and a conductive hollow fiber produced by the method. BACKGROUND ART [0002]

The present invention relates to a method for producing a conductive hollow fiber and a conductive hollow fiber produced thereby, and more particularly, to a method for producing a conductive hollow fiber having excellent electrical conductivity and processability including a fluidized bed CNT, To a conductive hollow fiber produced.

BACKGROUND ART [0002] Various techniques have been proposed for conductive fibers that have excellent antistatic performance. For example, the surface of a fiber having no conductivity is plated with metal to give conductivity, or a resin in which a conductive carbon black is dispersed is coated on the fiber surface to form a conductive coating layer. However, they are not easily technically realized due to the complicated manufacturing process, or they are used for preparation for practical use of conductive fibers, for example, wear or repeated use in chemical treatment or yarn use in scouring for fibers There is a problem that the conductivity is easily deteriorated due to the external action and deviates from the practical range.

As other conductive fibers, metal fibers such as steel fibers are known to have excellent antistatic performance. However, since metal fibers are expensive and difficult to be fused with general organic materials, they are poor in flame retardancy, When the metal yarn is used as a conductive yarn, problems such as the stretchability of the fabric, the activity, the workability, and the stability of the fabric in application of the garment are likely to occur There is a limitation that the use thereof is limited.

As another type of conductive fiber, there has been proposed a method of forming a polymer in which a conductive carbon black is uniformly dispersed. However, since a large amount of conductive carbon black is contained in the conductive carbon black, There is a problem in that it is difficult to produce a fiber other than a special process because it is difficult to produce the fiber, the yield is low, the expensive filler is used too much, the cost is high, and the fiber properties are remarkably decreased.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the problems of the prior art described above and it is an object of the present invention to provide a method of manufacturing a master batch containing fluidized carbon nanotubes (CNTs) Disclosed is a method for producing a conductive hollow fiber having excellent electrical conductivity by solving the problem of nonuniform distribution of conductive particles and defective spinning by spinning using a hollow spinning nozzle.

Another object of the present invention is to provide a method for manufacturing a conductive hollow fiber of high quality at a low cost by reducing the cost and improving the processability and yield by using less expensive conductive filler.

According to one aspect of the present invention, there is provided a method of manufacturing a thermoplastic polymer master batch chip, comprising: preparing a thermoplastic polymer master batch chip comprising 5 to 10% by weight of a fluidized-bed carbon nanotube;

Radiating the thermoplastic polymer using a hollow spinning nozzle having a cross-sectional shape including an air layer; And

Followed by cooling and spinning. The present invention also relates to a method for producing a conductive hollow fiber.

Another aspect of the present invention is that the carbon nanotube is produced by the method of the present invention and has a carbon nanotube content of 0.1 to 3 wt%, a single fiber fineness of 0.5 to 2 denier, and a hollow portion ratio of 10 to 40% To a conductive hollow fiber.

According to the method of the present invention, it is possible to solve problems such as non-uniform distribution and defective radiation due to the conventional conductive material, and to provide a conductive hollow fiber which exhibits superior electric conductivity than fibers produced by composite spinning Can be produced.

In addition, since the wear comfort is greatly emphasized in comparison with the case of using metal yarn, it can be used for anti-static clothing such as general static electricity prevention as well as special use, and lightness and warmth can be exhibited by forming voids in the yarn.

Further, since the conductive material is uniformly distributed on the entire surface of the fiber to increase the contact area, the hollow fiber produced by the method of the present invention can be formed by placing a conductive material such as carbon black in the center portion, Which is higher than that of the fiber produced by the method of causing the fibers to protrude.

1 is a schematic cross-sectional view of a conductive hollow fiber produced according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a method for manufacturing a conductive hollow fiber by preparing a master batch in which a fluidized CNT is added as a conductive material and manufacturing a conductive hollow fiber having excellent electrical conductivity by using a hollow spinneret .

In the present invention, a thermoplastic polymer master batch chip in which 5-10 wt% of fluidized-bed carbon nanotubes are added is prepared, and then the hollow fiber spinning nozzle is used in which the thermoplastic polymer has a cross-sectional shape including an air layer. Followed by spinning and cooling to produce a conductive hollow fiber.

The thermoplastic polymer that can be used in the present invention is at least one selected from the group consisting of polyamides, polyacetals, polyketones, polyacrylics, polyolefins, polycarbonates, polystyrenes, polyesters, polyethers, polysulfones, polyfluoro polymers,

Polyamideimide, polyarylate, polyaryl sulfone, polyether sulfone, polyarylene sulfide, polyvinyl chloride, polyether imide, polytetrafluoroethylene, polyether ketone, and copolymers thereof or mixtures thereof. Can be used.

Specific examples of the thermoplastic polymer include polyamide 6, polyamide 6,6, polyamide 11, polyamide 12, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polyether terephthalate, polyether sulfone, polyphenylene But are not necessarily limited to, ether, polyvinylidene fluoride, polystyrene / acrylonitrile, polyetheretherketone, polyvinyl chloride, polyurethane, polyester urethane and the like.

In the present invention, a fluidized bed CNT is used as a conductive material. That is, the carbon nanotubes used in the present invention are synthesized using a fluidizing bed reaction. Fluidized-bed carbon nanotubes are a method of producing carbon nanotubes by dispersing and reacting metal catalyst particles and hydrocarbon-based source gases in a high-temperature reactor. That is, it is manufactured by growing carbon nanotubes in a metal catalyst by thermally decomposing a source gas while suspending a metal catalyst in a reaction furnace by a source gas.

The carbon nanotubes can be single-walled carbon nanotubes, multi-walled carbon nanotubes, or nanotube ropes.

The fluidized-bed carbon nanotubes having aspect ratios (length / width) of 10: 1 to 20: 1 and carbon nanotubes having an average length of 50 to 100 μm are used. If the aspect ratio of the carbon nanotubes is less than 10: 1, the content of the inorganic filler required for imparting conductivity increases, and if the aspect ratio is more than 20: 1, the spinnability and pressure rise may occur. Further, the electric conductivity of CNT is 10 ^-3 to 10 ^-5 Ω / cm, which is higher than that of the conventional carbon-based additive and has a fine particle size, so that a relatively small amount of highly conductive conductive fiber can be produced. In practice, if the same level of conductivity is to be imparted, the use amount of the inorganic additive can be reduced to 1/25 to 1/15 of the amount of carbon black and 1/5 to 1/6 of the amount of carbon fiber used.

In the present invention, the amount of CNT added to the thermoplastic polymer is suitably 5 to 10% by weight in the thermoplastic polymer masterbatch, and when less than 5% by weight, the conductive effect is insufficient even if the fluidized- If it exceeds 10% by weight, it is difficult to economically achieve profit.

In the mixing and melting step of the present invention, the thermoplastic polymer master batch chip containing the fluidized-bed carbon nanotubes is prepared, and then put into the extruder and melted. In the extruder, a pump is connected to send the molten material to the spinneret, followed by the extruder, followed by a polymer melt pump and a pump to melt the polymer material by heat.

Wherein the thermoplastic polymer masterbatch has a conductivity of less than 0.5 micrometers selected from the group consisting of gold, silver, platinum, palladium, copper, iron, zinc, titanium, tungsten, chromium, carbon, silicon, cobalt, nickel, and molybdenum, Particles can be further included.

In addition, a modifier such as a dispersing aid, a polymer-affinity auxiliary, an antioxidant, a stabilizer, a flame retardant, a colorant, an antibacterial agent, an ultraviolet absorber and the like may be added.

Next, in the spinning step, after the thermoplastic polymer master batch chip containing the fluidized-bed carbon nanotubes is mixed and melted, a spinning nozzle having a cross-sectional shape such that the spinning fibers mounted on the spinning block have a shape capable of containing an air layer Radiate. As shown in FIG. 1, the spinning nozzle may be a spinning nozzle having a C shape so that the fiber may contain an air layer. However, the spinning nozzle is not necessarily limited to the spinning nozzle, but may be circular, semi-circular, elliptical, Can also be used.

The mixed molten polymer is radiated by a spinning nozzle and then cooled by passing through a cooling device. At this time, the cooling device may use a rotary outer flow quenching (ROQ). In the single-side cooling system, there is a disadvantage in that uniformity and yarn physical property deviation occur due to uneven cooling problem of yarn due to cooling rate and cooling efficiency deviation in a portion close to and far from the cooling air delivering portion, and a cooling efficiency. So that non-uniform cooling of the filament can be minimized. At this time, a nozzle keeping heater is installed at the lower end of the spinning nozzle in order to prevent deterioration of the spinning performance due to the drop of the nozzle surface temperature due to the close cooling according to the characteristics of the cooling device.

In the fiber drawing step, the cooled polymer is stretched using a conventional stretching apparatus to have a monofilament fineness of 0.5-2 denier, a hollow portion ratio of 10-40%, a far infrared ray emissivity of 0.87 or higher in a 5-20 mu m wavelength region Thereby producing a conductive hollow fiber. That is, the first godet roller and the second godet roller

And at this time, oil can be oiled by the converging oil ring device before the first godet roller for uniform stretching. When the stretching and twisting are completed, the finally obtained yarn is wound on the winding device.

The conductive hollow fiber produced by the present invention has a carbon nanotube content of 0.1 to 3 wt%, a single fiber fineness of 0.5 to 2 denier, and a hollow portion of 10 to 40 wt%. When the content of the fluidized CNTs in the final fiber is less than 0.1% by weight, the conductivity performance is deteriorated. When the amount of the CNTs is more than 3.0% by weight, the functionalization is not improved and the spinning workability and physical properties are deteriorated. Do.

In the conductive hollow fiber of the present invention, the hollow portion accounts for 10 to 40%, preferably 20 to 30%, of the air layer formed. If the ratio of the hollow portion is less than 10%, the desired warming effect can not be expected. If the ratio is more than 40%, the processability in the manufacturing process may be deteriorated, and the feeling of wearing comfortably and color development may be deteriorated.

In the conductive hollow fiber of the present invention, an air layer is formed inside the fiber to provide excellent heat storage / warmth. Therefore, the yarn of the present invention can be used alone or as a yarn to be provided as a knitted fabric, a ski suit, a winter uniform, a blouse, a coat, a work cover, a curtain, etc., Furthermore, the conductive hollow fiber of the present invention is not limited to clothes, but can be used for nonwoven fabrics, medical applications, hygiene materials, and various living materials as fillers, and is used as a fiber laminate as an interior material for automobiles, noise absorbers, It is possible.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples, but these are for the purpose of explanation only, and the scope of protection of the present invention is not limited thereto.

Example

Example  One

A fluidized bed CNT having an average length of 200 nm and an aspect ratio of 100 or more was melt-mixed with nylon 6 (relative viscosity: 3.0, sulfuric acid: 95%) to prepare a master batch chip having a fluidized CNT content of 20 wt% Respectively. Then, the yarn was radiated at 295 DEG C at a speed of 2,600 m / min using a spinneret equipped with a nozzle having a C-shaped shape and a central annular discharge type cooling device and a nozzle heat keeping heater so that the final yarn could contain an air layer, The mixture was twisted at a false-twist ratio of 1.7 times using the equipment, and was made of a 65 denier / 72 polyamide false-twist yarn having a C-shaped cross-sectional shape as shown in Fig. The content of carbon nanotubes in the obtained polyamide fibers was 5% by weight, and their physical properties, processability and functionality were evaluated and are shown in Table 1 below.

Example  2

The procedure of Example 1 was repeated, except that the content of carbon nanotubes in the polyamide fibers was changed to 10 wt% in the practical example 1. The physical properties, processability and functionality of the obtained polyamide fibers were evaluated and are shown together in Table 1 below.

Comparative Example  One

A polyamide chip obtained by mixing 35% by weight of carbon black was spun at 295 DEG C at a rate of 2,600 m / min using a conventional spinning device and then twisted at a false-twist ratio of 1.7 times using a conventional twist-off facility to obtain a circular cross- / 72 filaments, and the properties, processability and functionality of the obtained polyamide hollow fibers were evaluated and are shown in Table 1 below.

Comparative Example  2

Using the same material as in Example 1, the mixture was radiated at 295 DEG C at a rate of 2,600 m / min using a spinning device equipped with a nozzle having a general circular shape, a central annular discharge type cooling device, and a nozzle heat keeping heater, The resulting polyamide fibers were evaluated in terms of physical properties, processability, and functionality of the obtained polyamide fibers. The results are shown in Table 1 below. ≪ tb > < TABLE >

Radioactive burglar Shindo Conductivity performance (Ω / cm) Early Repeat 50 times after washing Example 1 Great 4.46 31.2 3.24 x 10 ⁶ 3.64 x 10 ⁷ Example 2 Good 4.90 27.5 1.38 x 10 ⁶ 8.77 x 10 ⁷ Comparative Example 1 Great 4.74 34.4 6.76 x 10 ⁷ 6.97 x 10 ⁸ Comparative Example 2 Great 4.70 32.2 3.98 x 10 ⁷ 2.59 x 10 ⁸

<< Property Evaluation Method >>

1. Radioactivity : Radiation temperature: 260 ° C, spinning speed: 750m / min. The number of yarns per spinning hour was expressed as follows. Excellent when the yarn count was less than one yarn per 24 hours, good within 3 times, And more than two times.

2. Strength and elongation : The strength and elongation of the fiber were measured using a tensile strength tester manufactured by Instron under conditions of a sample length of 20 cm and a tensile speed of 25 cm / min.

3. Conducting performance : The surface static electricity was removed with a charge material under standard laboratory conditions with KS K 0180 (electrical resistance test method of the yarn), and the resistance value was measured using a tip at both ends of 20 cm intervals.

As can be seen from the results shown in Table 1, the polyamide-conductive hollow fiber produced by the method of the present invention has excellent electrical conductivity and excellent spinnability.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Those skilled in the art will readily appreciate that various changes, modifications, and variations may be made without departing from the spirit and scope of the present invention, as defined by the following claims and accompanying drawings. Accordingly, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims (7)

Preparing a thermoplastic polymer master batch chip comprising 5 to 10% by weight of a fluidized-bed carbon nanotube;
Radiating the thermoplastic polymer using a hollow spinning nozzle having a cross-sectional shape including an air layer; And
And cooling after spinning,
Wherein the fluidized-bed carbon nanotubes have an aspect ratio (length / width) of 10: 1 to 20: 1 and an average length of the carbon nanotubes is 50 to 100 占 퐉.
The method of claim 1, wherein the thermoplastic polymer is selected from the group consisting of polyamide, polyacetal, polyketone, polyacrylic, polyolefin, polycarbonate, polystyrene, polyester, polyether, polysulfone, polyfluoropolymer,
Polyether sulfone, polyarylene sulfide, polyvinyl chloride, polyetherimide, polytetrafluoroethylene, polyether ketone, and copolymers thereof, in the group consisting of polyamideimide, polyamideimide, polyarylate, polyarylsulfone, And at least one selected from the group consisting of the conductive fibers and the conductive fibers.
delete The method of claim 1, wherein the cross-section of the hollow spinning nozzle is C-shaped, circular, semicircular, circular, or D-shaped.
The method of producing a conductive hollow fiber according to claim 1, wherein the thermoplastic polymer is polyamide and the cross section of the spinning nozzle is C-shaped.
The thermoplastic polymer masterbatch according to claim 1, wherein the thermoplastic polymer masterbatch is composed of gold, silver, platinum, palladium, copper, iron, zinc, titanium, tungsten, chromium, carbon, silicon, cobalt, nickel and molybdenum Wherein the conductive particles further comprise conductive particles selected from the group consisting of the conductive particles.
A carbon nanotube according to any one of claims 1 to 3, which has a cross-sectional shape that can include an air layer and has a carbon nanotube content of 0.1 to 3 wt% Wherein the single yarn fineness is 0.5 to 2 denier and the ratio of the hollow portion is 10 to 40%.

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