KR-20260065416-A - CARBON NANOTUBE COMPOSITE WIRE AND METHOD FOR PRODUCING THE SAME

KR20260065416AKR 20260065416 AKR20260065416 AKR 20260065416AKR-20260065416-A

Abstract

The present invention relates to a carbon nanotube composite wire having a coating layer comprising a silicon-based insulating coating agent on the surface of the wire and a conductive polymer in the internal pores, and a method for manufacturing the same.

Inventors

송경화
이석민
윤덕우
김관식

Assignees

현대자동차주식회사
기아 주식회사

Dates

Publication Date: 20260508
Application Date: 20241101

Claims (15)

Carbon nanotube wire containing a conductive polymer in internal pores; and A coating layer formed on at least a portion of the surface of the carbon nanotube wire; comprising A carbon nanotube composite wire in which the coating layer comprises a silicon-based insulating coating agent.
In paragraph 1, The above-mentioned conductive polymer is a carbon nanotube composite wire in which one or more are selected from the group consisting of polythiophene-based polymers, polypyrrole-based polymers, and polyaniline-based polymers.
In paragraph 1, The above conductive polymer is a carbon nanotube composite wire in which PEDOT:PSS is used.
In paragraph 1, A carbon nanotube composite wire in which the weight ratio between the conductive polymer and the carbon nanotube wire is 1:99 to 20:80.
In paragraph 1, A carbon nanotube composite wire having a peak in one or more regions selected from the 1250 to 1350 cm⁻¹ region, the 1050 to 1150 cm⁻¹ region, and the 900 to 1000 cm⁻¹ region in the graph obtained from FT-IR analysis.
In paragraph 1, The above-mentioned silicon-based insulating coating agent is a carbon nanotube composite wire having a surface energy of 30 mJ/ m² or less.
In paragraph 1, The above-mentioned silicone-based insulating coating agent is a carbon nanotube composite wire comprising one or more selected from the group consisting of polydimethylsiloxane, methylphenyl silicone resin, and silicone-based insulating coating agents in which some of their functional groups are modified or substituted.
In paragraph 1, A carbon nanotube composite wire in which the weight ratio between the above-mentioned silicon-based insulating coating agent and the carbon nanotube wire is 0.1:99.9 to 5:95.
Step (S1) of obtaining an aerogel containing carbon nanotubes through direct spinning; Step (S2) of manufacturing a carbon nanotube wire by immersing the above aerogel in a solution containing a conductive polymer; Step of winding the manufactured carbon nanotube wire (S3); and A method for manufacturing a carbon nanotube composite wire comprising the step (S4) of forming a coating layer containing a silicon-based insulating coating agent on the surface of a wound carbon nanotube wire.
In Paragraph 9, A method for manufacturing a carbon nanotube composite wire in which the content of the conductive polymer in a solution containing the above-mentioned conductive polymer is 5 to 40 weight%.
In Paragraph 9, A method for manufacturing a carbon nanotube composite wire in which the solvent of the solution containing the above-mentioned conductive polymer is water, an alcohol-based solvent, acetone, or a mixture thereof.
In Paragraph 9, The above S3 step includes a first winding step and a second winding step, and A method for manufacturing a carbon nanotube composite wire in which the winding speed of the second winding step is higher than the winding speed of the first winding step.
In Paragraph 9, A method for manufacturing a carbon nanotube composite wire, wherein the above S4 step is performed by immersing the wound carbon nanotube wire in a solution containing a silicon-based insulating coating agent and then drying it.
In Paragraph 13, A method for manufacturing a carbon nanotube composite wire, wherein the viscosity of a solution containing the above-mentioned silicone-based insulating coating agent is 30,000 cps or more and 40,000 cps or less.
In Paragraph 13, A method for manufacturing a carbon nanotube composite wire, wherein the above drying is performed at a temperature of 100°C or higher and 200°C or lower.

Description

Carbon nanotube composite wire and method for producing the same The present invention relates to a carbon nanotube composite wire comprising a conductive polymer in the internal pores of the carbon nanotube wire and a silicon-based insulating coating agent on the external surface, and a method for manufacturing the same. Carbon nanotubes have a structure in which hexagonal carbon rings are connected and arranged in single or multilayer tubes. Due to their lightweight nature and excellent properties such as electrical and thermal conductivity, elasticity, and mechanical strength, they are widely applied as novel materials in various fields. Conventionally, most carbon nanotubes have been used in the form of composites mixed with matrices such as polymers, serving as fillers to enhance the performance of the matrix. However, with the recent advancement of technology for manufacturing fiber-type carbon nanotubes, various new technologies for utilizing carbon nanotubes in fiber form are being researched, and carbon nanotubes are gaining attention as a material capable of replacing conventional wires. Most existing wire materials are composed of copper and metals, and carbon nanotubes have a lower density than copper, which is relatively lighter among metals. Therefore, replacing existing copper or metal wires with carbon nanotube wires can enable material weight reduction. For example, changing the material of wires used in automotive parts to carbon nanotubes allows for vehicle weight reduction, which in turn can improve fuel efficiency. There are various methods known for manufacturing carbon nanotube wires, among which direct spinning has the advantage of being able to continuously produce very long carbon nanotube wires. Direct spinning involves reacting a catalyst and a carbon source at a high temperature in a vertical furnace, obtaining an aerogel-shaped carbon nanotube sock at the bottom of the vertical furnace which serves as the outlet, and then manufacturing the carbon nanotube wire by pulling and winding the carbon nanotube sock. In particular, the carbon nanotube sock shrinks upon contact with a solvent located below the vertical furnace, and a wire shape is formed during this process. The solvent shrinks the carbon nanotubes within the sock to increase density while simultaneously enveloping the surface of the carbon nanotubes coming out, thereby ensuring that a stable shape is maintained. However, since carbon nanotube wires are obtained through such a rapid shrinkage process, a large number of internal pores exist within the strands of the carbon nanotube wires. These irregular pores reduce the conductivity of the carbon nanotube wires and also degrade mechanical properties such as tensile strength. Therefore, to solve these disadvantages, a post-processing step is performed on the manufactured carbon nanotube wires. This post-processing step involves compressing the carbon nanotubes with equipment such as rollers or removing internal air through heat treatment. However, even with such post-processing steps, it is not easy to remove small internal pores within the carbon nanotube wires. Consequently, a new material is required that can minimize the reduction in conductivity caused by the internal pores of the carbon nanotube wires. Meanwhile, conventional wire materials such as copper or metal wires are used after undergoing an insulating coating, and carbon nanotube wires also require such an insulating coating. Generally, various methods for insulating coating materials such as copper wires are known; however, since the characteristics of carbon nanotube wires differ from those of copper or metal wires, an insulating coating method suitable for carbon nanotube wires is required. For example, results indicate that conventional compatibilizers for insulating coatings are not suitable as insulating coating agents for carbon nanotube wires. Therefore, it is necessary to develop an insulating coating method optimized for carbon nanotube wires and carbon nanotube wires having an insulating coating layer formed by said method. Figure 1 shows a graph obtained from FT-IR analysis results for a carbon nanotube composite wire obtained after the winding step during the manufacturing process of Example 1, a carbon nanotube wire of Comparative Example 1, and a conductive polymer, PEDOT:PSS. The present invention will be described in more detail below. Terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Carbon nanotube composite wire The present invention provides a carbon nanotube composite wire comprising a carbon nanotube wire containing a conductive polymer in an internal pore and a coating lay