To provide a composite black oxide particle excellent in blackness, oxidation resistance, dispersibility at painting and the surface smoothness of a coated film and to provide its manufacturing method, a black paint and a black matrix.
The spinel-type or inverse-spinel-type composite black oxide particle consists of oxides of cobalt, copper and manganese, has a molar ratio of copper to cobalt of 0.1-0.5 and has a molar ratio of manganese to cobalt of 0.2-1.0. The method for manufacturing the composite black oxide particle is characterized in that a mixed metal salts aqueous solution prepared by water soluble salts of cobalt, copper and manganese and an alkali hydroxide are mixed for neutralization, the obtained slurry of the metal hydroxides is oxidized at higher than 40°C and 60°C or lower while keeping its pH value of 10-13 and an obtained precursor is aged at 80-150°C and heat-treated at 400-700°C and for more than 1 hour and 3 hours or less after solid-liquid separation.
FUJIYASU SHOICHI
KATSUYAMA KOICHI
SHIMAMURA HIROYUKI
