| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic recording medium having improved durability at high and low temps. and fit for high density recording as well as to enhance dispersibility and the mechanical characteristics of a coating film by specifying a surface modifying material for magnetic powder and a binder. SOLUTION: A magnetic layer contg. ferromagnetic powder and a binder is formed on a flexible nonmagnetic substrate to obtain the objective magnetic recording medium. Ferromagnetic powder with a coating film of an inorg. Al compd. on the surface is used as the ferro-magnetic powder and a resin having tert. amino groups or quat. ammonium groups is used as the binder. Powder of a ferromagnetic metal such as Fe, Ni or Co or a magnetic alloy based on the metal, magnetic powder of iron oxide such asγ-Fe2 O3 or Fe3 O4 or magnetic powder of a metal oxide such as Cr2 O3 is concretely used as magnetic powder. The resin for the binder is selected from among various resins, but since vinyl chloride resin and cellulosic resin have high ability to disperse ferromagnetic powder and polyurethane resin gives a magnetic coating film excellent in wear resistance, one or more of these resins are used as the binder.
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