| 摘要 |
A magnetic recording material, preferably for tape recorders which are designed for the iron oxide bias setting and for a playback equalization of 120 mu s, consisting of a support and at least two layers containing magnetic pigments and binders and differing in coercivity and layer thickness, the uppermost layer containing as acicular, magnetic pigment thermally stabilized magnetite containing from 0.1 to 5% by weight of Cd, Pb, Ca, Mg, Zn, Al, Cr, W, P and/or B based on Fe3O4. The pigments have an average crystallite size of from 30 to 35 nm and a coercivity of from 28 to 36 KA/m. These double-layer tapes have a low bias level and a high dynamic range despite a playback equalization of 120 mu s. |
