KR101493730B1 - Conductive composite fiber - Google Patents

Abstract

The present invention relates to a composite fiber having a double structure having excellent conductivity by using a carbon nanotube (CNT) as a conductive material. More specifically, the present invention relates to a core of a synthetic fiber material, A jacket made of polyamide or carbon nanotube coated with a sheath made of carbon nanotubes and having excellent conductivity and a polyamide having excellent affinity with the carbon nanotubes is formed, , And the like.

Composite fiber, conductive, carbon nanotube, polyamide, synthetic fiber, coextrusion

Description

Conductive composite fiber [0002]

The present invention relates to a composite fiber having a double structure having very excellent conductivity by using carbon nanotubes as a conductive material. More specifically, the present invention relates to a carbon nanotube having excellent conductivity and a sheath made of polyamide having excellent affinity with the carbon nanotube And thus the conductive characteristics of the conductive hybrid fiber can be improved.

In the modern society, many efforts are being made to improve the performance of electroconductive fibers and to apply them to the inside of clothes. For example, in recent years, the term Smart Wear has emerged, which is also referred to as future fibers. NT, BT, ET, etc., which is a new concept clothing which combines the function of the fiber (fabric) or the garment itself to react by sensing the external stimulus and the digitalized properties not possessed by the conventional fiber It refers to a new concept of futuristic clothing that is not based on the traditional textile or clothing concept by combining new technologies. Typically, it is a high-functional textile material garment incorporating a digital sensor, a GPS, a microcomputer, and a small MP3 player.

Our textile industry in the 1970s led the high growth of the Korean economy. As of 2000, it was the largest trade industry with 12% of total exports and trade balance of USD 13.7 billion. However, Taiwan, China, Southeast Asia and other latecomers in the pursuit of growth is facing the limit. In particular, Korea's textile industry is still focused on the middle and low-end apparel industry compared to advanced countries, and the proportion of industrial fibers with infinite growth potential is only 20%. Accordingly, for the advancement of the textile industry and the high value-added, it is urgently required to develop new fibers and smartwear that can present the extreme increase in the material performance and the maximization. In order to realize such clothing, To be developed or improved for apparel products.

For the development of smartware, it is essential to make semiconductor chips, sensors, and digital devices ultra-compact and lightweight so that they can be embedded in fiber or clothing. For example, clothing or design design technology that integrates digital devices / And insulating material for insulating clothing can be listed as representative system technologies.

Therefore, it is possible to derive digitized clothing products by combining textile, electric, electronic, computer, and cognitive science technologies.

In order to derive digitized garment products by integrating digital devices / functions as described above, a variety of technologies are required. Of all, important technology is connected to high value-added components such as digital devices or semiconductors integrated into clothes, And conductive fibers that connect digital devices or their components while being undamaged by other effects.

Accordingly, research and development on conductive fibers through which electricity readily flows have been actively conducted. For example, Korean Patent Laid-Open Publication No. 2008-34824 (entitled "Conductive Fibers and Brushes") discloses conductive fibers and brushes using carbon black as a main conductive component in a fiber-forming polymer, A conductive composite fiber comprising a conductive polymer layer containing carbon black and a protective polymer layer for protecting the conductive polymer layer is disclosed in Korean Patent Publication No. 2001-50879 2002-48410 (the name of the invention: a core-sheath composite conductive fiber) discloses a composite conductive fiber comprising a core made of a polyester material and a sheath in which a polyester and carbon black are mixed, and Korean Patent Laid- -76032 (entitled conductive polyester fiber), polytrimethylene terephthalate material And a second component comprising a mixture of polytrimethylene terephthalate and carbon black.

However, as described above, conventional conductive fibers formed using carbon black as a conductive material have a very low conductivity and other electrical characteristics. Therefore, a digital device / It is extremely difficult to draw out the problem.

 Therefore, by developing fibers with excellent conductivity and other electrical characteristics, solving various problems associated with the connection of digital devices or their components integrated in clothes, it is necessary to strive to cope with the future textile industry It is.

Therefore, an object of the present invention is to provide a conductive composite fiber which can be used for various purposes because its electrical characteristics are greatly improved by including a carbon nanotube having excellent conductivity and a shell made of polyamide having excellent affinity with the carbon nanotube have.

In order to achieve the above object, the present invention provides a core material of a synthetic fiber material, a polyamide 80 to 99% by weight coated on the outside of the core material, and a shell of 1 to 20% by weight of carbon nanotubes, Sectional area ratio is 5 to 90% of the total cross-sectional area of the fiber.

The conductive composite fiber according to the present invention includes a carbon nanotube having excellent conductivity and a shell made of polyamide having excellent affinity with the carbon nanotube, and thus can be utilized in a variety of high-tech applications such as smart ware It has the effect of making.

The present invention is characterized in that it includes a skin containing a carbon nanotube having excellent conductivity.

The carbon nanotubes used in the present invention have a structure in which graphite is rolled in the form of a cylinder having a diameter of 1 to 100 nm and are not only excellent in mechanical durability and chemical stability but also have properties of semiconductors and conductors It is a material that is applied to various fields because of its small diameter, long length and hollow character.

Carbon nanotubes are classified into single-walled carbon nanotubes, multi-walled carbon nanotubes, and nanotube ropes according to the shape of the carbon nanotubes. The most excellent properties are known as single-walled carbon nanotubes, but they are not so widely used because they are expensive. In addition, carbon nanotubes can be symmetrically structured in the form of zigzag, semiconductor and armchair depending on the carbon arrangement of the carbon nanotubes. However, instead of such a symmetrical structure, a honeycomb-shaped hexagonal tube axis Therefore, it may have a chiral structure arranged in a spiral.

     Finally, the carbon nanotubes have a large aspect ratio, have various structures and physical properties according to the synthesis method, have high mechanical strength, chemically inert on the surface, and have excellent electrical conductivity. .

The electrical conductivity of carbon nanotubes is 10 ^-3 -10 ^-5 Ω / cm, which is higher than that of existing carbon-based additives and has a finer particle size. Therefore, carbon nanotubes can be used at a ratio of 1/4 to 1/5 of carbon black, It is possible to design a highly conductive polymer material with a relatively small amount of about 4/4.

The conductive conjugate fiber of the present invention will be described in detail with reference to the drawings and examples.

1 shows a cross-sectional structure of a conductive conjugate fiber of the present invention.

Referring to FIG. 1, the conductive composite fiber of the present invention includes a core material made of a synthetic fiber.

A core having a certain diameter is formed at the center of the conductive composite fiber so as to support the outer shell having excellent conductivity in the conductive composite fiber.

As described above, the core 1 constituting the central portion of the conductive composite fiber is made of a general synthetic fiber material, for example, polyester, polyethylene, polypropylene, polyacrylonitrile butadiene styrene, polystyrene, polycarbonate and polyamide And synthetic fibers which are used singly or mixedly.

The core material 1 of the above-described material supports the conductive sheath 2 to provide the conductive composite fiber with mechanical properties.

In addition, the conductive composite fiber of the present invention comprises 80 to 99% by weight of polyamide coated on the outside of the core material, and 1 to 20% by weight of the carbon nanotube shell.

A carbon nanotube having excellent conductivity and a polyamide having an excellent affinity with the carbon nanotube are mixed in a predetermined amount to form a sheath 2 having conductivity, .

That is, carbon nanotubes that provide conductivity to conductive hybrid fibers have a very excellent conductivity, but are inferior in dispersibility. In order to easily disperse carbon nanotubes having such properties, carbon nanotubes have affinity with carbon nanotubes Excellent polyamides are mixed in a certain amount to constitute a master batch used for manufacturing the envelope (2).

Specifically, in order to manufacture the outer shell 2 coated on the outside of the core material 1, 80 to 99% by weight of polyamide and 1 to 20% by weight of carbon nanotubes are mixed to form a master batch chip, And the master batch melt formed by melting the batch chip is extruded to constitute the shell 2. When the content of the carbon nanotubes contained in the master batch chip for constituting the shell 2 is less than 1 wt%, conductivity is not provided to the shell 2 formed in the master batch chip, and carbon contained in the master batch chip If the content of the nanotubes exceeds 20% by weight, the flow property of the master batch melt is lowered, which makes it difficult to produce the conductive composite fiber, thereby causing problems in workability.

The composite fibers of the above-described materials and the master batch are co-extruded to produce a conductive composite fiber having a composite structure of the core 1 and the shell 2. [

Specifically, the synthetic resin chip and the master batch chip are separately melted to form a synthetic resin melt and a master batch melt, respectively. The melted synthetic resin melt and the master batch melt are co-extruded from a co-extrusion nozzle having a double structure to form a core material 1 ) And the conductive shell (2), wherein the cross-sectional area ratio of the shell (2) is 5 to 90% of the total cross-sectional area of the composite fiber. If the cross-sectional area ratio of the conductive shell 2 is less than 5% of the total cross-sectional area of the composite fibers, conductivity is not expressed due to insufficient content of the carbon nanotubes in the composite fibers, The core material 1 of the composite fiber does not sufficiently support the outer shell 2, so that the mechanical properties thereof are deteriorated and it is difficult to put it to practical use.

The high-tech clothes such as smart ware are manufactured by using the conductive composite fiber constituted as described above.

The production and properties of the conductive conjugate fiber of the present invention will be described in detail with reference to specific examples. It is to be understood, however, that the following examples are illustrative only and do not limit the present invention.

≪ Example 1 >

1. A master batch chip was formed by mixing 90 wt% of polyamide having a relative viscosity of 2.47, 10 wt% of carbon nanotubes having an average diameter of 50 nm and an aspect ratio of 100, and molding the mixture into a chip form.

2. A polyester chip, which is a synthetic fiber for forming a core material having a circular cross section, is melted at 265 DEG C and co-extruded to form a double-layered conductive composite fiber composed of a core material and an outer shell, Of the cross-sectional area ratio was 5/5.

≪ Example 2 >

Except that 87.5% by weight of a polyamide having a relative viscosity of 2.47, an average diameter of 50 nm, and 12.5% by weight of carbon nanotubes having an aspect ratio of 100 were mixed and molded into chip form to constitute a master batch chip.

≪ Example 3 >

Except that 85 wt% of a polyamide having a relative viscosity of 2.47, an average diameter of 50 nm, and 15 wt% of carbon nanotubes having an aspect ratio of 100 were mixed and molded into a chip form to constitute a master batch chip.

<Example 4>

1. A master batch chip was formed by mixing 90 wt% of polyamide having a relative viscosity of 2.47, 10 wt% of carbon nanotubes having an average diameter of 50 nm and an aspect ratio of 100, and molding the mixture into a chip form.

2. A polyester chip, which is a synthetic fiber for forming a core material having a circular cross section, is melted at 265 DEG C and co-extruded to form a double-layered conductive composite fiber composed of a core material and an outer shell, Was 2/8. &Lt; tb &gt; &lt; TABLE &gt;

&Lt; Example 5 >

Except that 87.5% by weight of a polyamide having a relative viscosity of 2.47, an average diameter of 50 nm, and 12.5% by weight of carbon nanotubes having an aspect ratio of 100 were mixed and molded into a chip form to constitute a master batch chip.

&Lt; Example 6 >

Except that 85 wt% of a polyamide having a relative viscosity of 2.47, an average diameter of 50 nm, and 15 wt% of carbon nanotubes having an aspect ratio of 100 were mixed and molded into a chip form to constitute a master batch chip.

&Lt; Comparative Example 1 &

1. A master batch chip was formed by mixing 90 wt% of a polyamide having a relative viscosity of 2.47 and 10 wt% of carbon black and molding the mixture into a chip form.

2. A polyester fiber as a synthetic fiber for forming the master batch chip and a core material is melted at 265 DEG C and co-extruded to constitute a double-layered conductive composite fiber composed of a core and an outer jacket, Lt; RTI ID = 0.0 &gt; 5/5. &Lt; / RTI &gt;

&Lt; Comparative Example 2 &

87.5% by weight of a polyamide having a relative viscosity of 2.47 and 12.5% by weight of carbon black were mixed and molded into a chip form to form a master batch chip.

&Lt; Comparative Example 3 &

1. A master batch chip was formed by mixing 90 wt% of a polyamide having a relative viscosity of 2.47 and 10 wt% of carbon black and molding the mixture into a chip form.

2. A polyester chip, which is a synthetic fiber for forming a core material having a bar-shaped cross section, is melted at 265 DEG C and co-extruded to form a core material having a rod-shaped cross section and a cross- The composite fibers were prepared so that the cross-sectional area ratio of the core / sheath was 2/8.

The process conditions and the physical properties of the composite fibers produced according to Examples 1 to 6 and Comparative Examples 1 to 3 are shown in Table 1 below.

<Table 1>

division Sectional ratio (core / sheath) Conducting ash content of master batch conductivity Sacrifice Example 1 5/5 10 ○ ◎ Example 2 5/5 12.5 ◎ ○ Example 3 5/5 15 ◎ × Example 4 2/8 10 ◎ ○ Example 5 2/8 12.5 ◎ △ Example 6 2/8 15 ◎ × Comparative Example 1 5/5 10 ○ ○ Comparative Example 2 5/5 12.5 ○ × Comparative Example 3 2/8 10 ○ ○

(?: Excellent,?: Good,?: Fair, X: poor)

In Table 1, the conductive composite fibers according to the embodiments of the present invention are superior to the conductive composite fibers according to the comparative examples in conductivity and manufacturability, and can be used in various high-tech applications such as smart ware.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims and their equivalents. And such changes are, of course, within the scope of the claims.

1 is a cross-sectional structural view of a conductive conjugate fiber of the present invention

DESCRIPTION OF THE REFERENCE NUMERALS

1: Core

2: envelope

Claims (2)

Core of synthetic fiber material; And And 80 to 99% by weight of polyamide coated on the outside of the core, 10 to 15% by weight of carbon nanotubes (CNT) having an average diameter of 50 nm and an aspect ratio of 100, Sectional area ratio of the shell is 60 to 90% of the total cross-sectional area of the fiber, Wherein the core material is a synthetic fiber selected from the group consisting of polyacrylonitrile butadiene styrene and polycarbonate, and used alone or in admixture. delete

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