| 摘要 |
PURPOSE:To eliminate distortion of the middle band to reduce outut fluctuation by providing a magnetic layer including magnetite or cobalt adsorption magnetite on a support material and by providing the second magnetic layer including cobalt adsorption gamma-Fe2O3 on this magnetic layer. CONSTITUTION:The magnetic layer including magnetic powder gamma-Fe2O3 including magnetite or cobalt adsorption magnetite is formed on the nonmagnetic support material such as a polyester film. Next, the second magnetic layer including cobalt adsorption gamma-Fe2O3 is formed on this magnetic layer so that coercive force, the residual magnetic flux density and thickness of the second magnetic layer may be 590-800 oersteds, 1200 gausses or more, and 1.5-3.0mu respectively. As a result, sound recording sensitivity is improved for frequencies of all bands of the magnetic recording medium used for an audio cassette tape recorder, etc., and the magnetic recording medium becomes superior in dynamic range. |
