PRODUCTION OF TANTALUM (V) NITRIDE PIGMENT, ITS PIGMENT AND USE OF THE PIGMENT

摘要

PROBLEM TO BE SOLVED: To increase lightness and to enable use for various purposes by nitriding tantalum oxide in the presence of water-soluble salts of an alkali metal and an alkaline earth metal or nitriding it at a specified temperature in a melt of a salt having a specified melting point, dissolving the nitrided product in water and extracting the objective pigment. SOLUTION: Tantalum (V) oxide, tantalum (V) oxide hydrate or tantalum (V) oxynitride is nitrided with ammonia in the presence or absence of a flux at 500-1,000 deg.C. This nitriding is carried out in the presence of one or more water-soluble salts selected from a series including nitrates, chlorides and carbonates of alkali metals and alkaline earth metals. The tantalum compound may be nitrided at 100-600 deg.C for 1-100 min in a melt of a salt having 100-600 deg.C melting point. Before or after washing an optionally present flux, the nitrided product is treated. This salt is then dissolved in water and the objective pigment is extracted.