BLACK COMPOSITE OXIDE PARTICLE, BLACK SLURRY, BLACK PASTE, AND BLACK MATRIX

摘要

Disclosed is a black composite oxide particle which comprises oxides of cobalt and copper, has an average primary particle diameter of 0.03 to 0.5 μm, has a D50 value of 0.05 to 1.0 μm as measured by the laser diffraction scattering method in terms of the number of particles, and has a granular shape. The particle preferably comprises 40 to 65 mass% of cobalt and 5 to 30 mass% of copper. The particle preferably has a tap density of 0.8 to 2.0 g/cm3, a density of 6.0 to 7.0 g/cm3 and a saturation magnetization of 5 Am2/kg or less.