Acicular hematite particles for non-magnetic undercoat layer of magnetic recording medium

摘要

Acicular hematite particles suitable as non-magnetic particles for a non-magnetic undercoat layer of a magnetic recording medium have a geometrical standard deviation of the major axis diameter of not more than 1.50, a geometrical standard deviation of the minor axis diameter of not more than 1.35, a BET specific surface area of 35.9 to 150 m<2>/g and an average major axis diameter of 0.004 to 0.295 mu m.