Non-magnetic black particles and their use as pigments or fillers

摘要

Non-magnetic black particles containing: (i) Fe as a main component; (ii) from 5 to 40% by weight of manganese based on the weight of the particles; (iii) not more than 500 ppm of a soluble sodium salt calculated as Na; and (iv) not more than 200 ppm of a soluble sulfate calculated as SO4; and having: (a) a hematite structure; (b) an average particle size or trom 0.1 to 10.0 mu m; and (c) a pH of not less than 5.5.