| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to obtain high durability and to improve regenerative output and overwriting characteristic by dispersing ferromagnetic powder consisting of Fe, Ni, Fe-Co, Fe-Ni, Cl-Ni, Co-Ni-Fe, etc., alone or their alloys into a binder, forming magnetic layers on a nonmagnetic base and specifying the magnetic characteristics of the magnetic layers. SOLUTION: The magnetic layer are formed on the nonmagnetic base consisting of polyethylene terephthalate, arom. polyacide, etc., by dispersing the ferromagnetic powder into the binder of a polyurethane resin. The ferromagnetic powder of which the specific surface area by SBET is preferably >=30 to <50m<2> /g and the saturation magnetizationσs is preferably 140 to 170emu/g is used. In addition, the magnetic layers are regulated to the productπof the coercive force Hc(σe) in the longitudinal direction within the plane and magnetic fluxϕm(G.cm) within a range of 100 to 160, by which the electromagnetic conversion characteristics are improved.
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