Magnetic recording medium having cobalt adsorbed iron oxide layer

摘要

A magnetic recording medium comprises a substrate coated with a magnetic composition comprising a cobalt adsorbed iron oxide powder with a phosphoric ester type anionic surfactant at a ratio of 2 wt. % or more and a binder at a ratio of said iron oxide powder to said binder of 4 or more. A magnetic recording medium has a coercive force Hc of 950 to 1200 Oe and a residual magnetic flux phi r of 0.35 to 0.6 maxwell.