NICKEL OXIDE PARTICLE AND ITS PRODUCTION

PROBLEM TO BE SOLVED: To obtain nickel oxide particles which shows excellent blackness, heat resistance, workability, high safeness without showing carcinogenicity and toxicity and which is useful as a nonmagnetic black pigment by specifying the average particle size and the BET specific surface area. SOLUTION: Such nickel oxide is selected that has =50m /g BET specific surface area, preferably 50 to 250m /g, and more preferably, >=70 black degree, especially >=80, and >=300 deg.C heat resistance temp., especially >=400 deg.C. This nickel oxide is obtd. by mixing a water-soluble nickel salt (e.g. Ni(NO3 )2 .7H2 O) and an alkali soln. (e.g. NaOH) with >=2.0 molar ratio, preferably 2.0 to 3.0 molar ratio of the alkali metal ion to Ni ion, and then burning the obtd. precipitate at 280 to 400 deg.C, preferably 300 to 350 deg.C.