A carbon black (CB) and carbon nanotube (CNT) master batch and a Nylon66/conductive material composite were prepared by using a biaxial extruder to study the physical properties of the Nylon66/conductive material composite according to the content of the conductive material and the application of the master batch. CB, CNT, nickel-coated carbon fibers (Ni-CF), and metal fillers were used as the conductive material, and the master batch was applied to CB and CNT. The synergistic effect was considered for the electrical characteristics of CB and CNT, and the surface resistivity enhancement was confirmed when prepared by a blend. In the production of Nylon66/conductive material composites, the Ni-CF content could be adjusted by mixing CB/CNT, which is considered to be advantageous in improving processability such as injection molding. It was confirmed that the content of Ni-CF capable of satisfying 50 dB of electromagnetic wave shielding performance was 20 wt%. It was confirmed that metal fillers have a circular structure, and their reinforcing effects in mechanical and electrical properties are inferior to those in Ni-CF.

전도성 물질 함량 및 마스터 배치 적용에 따른 나일론66/전도성 물질 복합체의 물성을 연구하기 위해 이축압출기를 이용하여 카본블랙(CB)과 탄소나노튜브(CNT) 마스터 배치 및 나일론66/전도성 물질 복합체를 제조하였다. 전도성 물질로 CB, CNT, 니켈 코팅 탄소섬유(Ni-CF) 및 금속 필러가 사용되었으며, CB와 CNT에는 마스터배치가 적용되었다. CB와 CNT의 전기적특성에 있어 상승효과를 고찰하였고, 혼합 사용시 표면 저항 개선 효과를 확인하였다. 나일론66/전도성 물질 복합체 제조에 있어 CB/CNT의 혼합사용으로 Ni-CF 함량 조절이 가능하였고, 이는 사출성형 등의 가공성 개선에 유리할 것으로 판단된다. 전자파 차폐 성능 50 dB를 만족시킬 수 있는 Ni-CF 함량은 20 wt%로 확인되었다. 금속 필러의 경우 원형의 구조로 기계적 특성과 전기적 특성에서의 보강 효과가 Ni-CF보다 열세함을 확인하였다.

Keywords: conductive materials, master batch, Nylon66, surface resistivity, shielding performance.