抄録
Preparation of composite conductive particles was attempted by coating fine electric conductive powders on insulative core particles so called dry coating. Compressive crushing mill was utilized for the dry coating process. Polymethylmethacrylate (PMMA, 8μm in diameter) was used as core particles. TiO2 coated with Ag (0.5μm in diameter), TiO2 coated with SnO2 (0.2μm) and SnO2 particles (less than 0.1μm) were employed as fine electric conductive powders. In the experiments, the rotation speed of the mill and the treatment time were changed. The coating condition and electric conductivity of the prepared particles were determined by volume specific resistivity, SEM observation of the particle surfaces and the compression moldings of the particles and X-ray micro-analysis.
As a result, composite particles with the functions of charge prevention and electromagnetic shield were procured by the dry coating process. In the conductive compression moldings, electric conductive routes were formed by the contacts of fine electric conductive particles and aggregates, coated or dispersed on the core particles. A network of good electric conductive routes was obtained when primary particles of the conductive powder were dispersed uniformly. It was obvious that the excellent conductive composite particles (coated with the fine electric conductive powder) were obtained when the particles were acted by shearing force and compression force.
