| 摘要 |
PROBLEM TO BE SOLVED: To obtain excellent electromagnetic transducing characteristics and transport durability by forming a magnetic layer in such a manner that when the surface of the magnetic layer is measured by a reflection high-speed electron beam diffraction method, the diffraction ring from the ferromagnetic powder partly includes theα-Fe diffraction pattern. SOLUTION: Ferromagnetic powder having a small particle size and small particle size distribution is used. A binder of low mol.wt. is used to increase the mobility of the ferromagnetic powder in the magnetic coating material during orienting. Also a solvent which can be easily dried is used and the blowing amt. for drying is increased to increase the drying rate and to suppress returning of the orientation. Thus, the orientation of the ferromagnetic powder on the outermost surface of the magnetic layer is controlled in such a manner that when the surface of the magnetic layer is measured reflection high-speed electron beam diffraction analysis, the diffraction ring from the ferromagnetic powder partly includes theα-Fe diffraction dots in the center of the longitudinal direction. This means that the ferromagnetic powder with good crystallinity is surely present with good orientation parallel in the longitudinal direction on the outermost surface of the magnetic layer. Therefore, excellent electromagnetic conversion characteristics and transport durability can be obtd.
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