Patent ID: 6087004
Filing Date: 2000-07-11
Classification: C01P,C08K,C09C,C09D,G11B,Y10S,Y10T

Abstract:
Non-magnetic black particles containing Fe as a main component and having a hematite structure, which particles contain manganese in an amount of 5 to 40% by weight based on the weight of said non-magnetic black particles, a soluble sodium salt in an amount of not more than 500 ppm, calculated as Na, and a soluble sulfate in an amount of not more than 200 ppm, calculated as SO.sub.4, and have an average particle size of 0.1 to 10.0 .mu.m, a geometrical standard deviation of particle diameters of not more than 2 and a pH of not less than 5.5.