PROCESS FOR PRODUCTION OF GRANULAR COBALT OXIDE BLACK PIGMENT, AND GRANULAR COBALT OXIDE BLACK PIGMENT

摘要

Disclosed is a process for production of a granular cobalt oxide black pigment. The process involves the step of performing the mixing neutralization of an aqueous solution of a salt of cobalt (bivalent) with an alkaline solution at a pH ranging from 10 to 13. After the mixing neutralization is initiated or completed, an oxygen-containing gas is bubbled in the mixed solution continuously while keeping the temperature of the mixed solution at 10 to 40ºC to produce a cobalt hydroxide precursor. The precursor is filtered, washed, dried, triturated, and then burned in a closed air at 500 to 850ºC for 0.5 to 3 hours, thereby producing the granular cobalt oxide black pigment.