| 摘要 |
PROBLEM TO BE SOLVED: To obtain good electromagnetic conversion characteristics and to maintain good electromagnetic conversion characteristics and travelling durability for a long time without changes with time by controlling the difference between the adsorbed water content W1 in a first specified range of an inorg. powder in a nonmagnetic layer and the adsorbed water content W2 in a second range of a ferromagnetic powder in a magnetic layer having average thickness of <= a specified value to <= a specified value. SOLUTION: This medium consists of a nonmagnetic layer and a magnetic layer successively formed on a nonmagnetic supporting body. The average thickness of the magnetic layer is specified to <=0.3μm. The nonmagnetic layer contains an inorg. powder having 0.2 to 4.0 wt.% adsorbed water content W1, while the magnetic layer contains a ferromagnetic powder having 0.2 to 3.0 wt.% adsorbed water content W2. The adsorbed water contents W1, W2 satisfy the relation of|W1-W2|<=1.0. Thereby, excellent initial values of gloss, surface roughness, overwriting erasing rate, coefft. of dynamic friction and characteristics against still operation can be obtd. and these initial values can be maintained after the medium is stored at a high temp. and high humidity.
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