PROCESS FOR THE PRODUCTION OF YELLOW TO RED PIGMENTS BASED ON NITRIDES AND OXIDENITRIDES

摘要

Nitride or oxidenitride based red to yellow pigments, such as tantalum(V) nitride and oxidenitrides containing tantalum, may be produced by passing ammonia over nitridable metal compounds, in particular oxide compounds, at 700.degree.C to 1250.degree.C. According to the invention, nitriding proceeds in a rotary tube or fluidised bed reactor in the presence of an oxide selected from the group consisting of SiO2, ZrO2, GeO2, SnO2, TiO2 and HfO2, under which conditions this oxide is not substantially nitrided.