| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to maintain a mildew-proofing property and to prevent deterioration in spite of the repetitive use of a recording medium by constituting >=2 layers on a nonmagnetic base, forming the uppermost magnetic layer to a specific thickness or below and incorporating the mildew-proofing agent into at least one layer of the lower layers exclusive of the uppermost layer. SOLUTION: The thickness of the uppermost magnetic layer of the magnetic recording medium is specified to <=1μm, by which the selfdegaussing loss in short wavelength recording and the thickness loss at the time of reproduction are lessened and output is improved. The mildew-proofing agent to be incorporated into at least one layer of the lower layers is so adjusted that the mildewproofing agent concn. of the uppermost magnetic layer attains the uppermost magnetic layer above the lowest growth prohibition concn. at all times after the production. The mildew-proofing agent concn. of the uppennost magnetic layer is preferably set at 100 to 500ppm of a binder. The mildew-proofing agent is prepd. by kneading, for example, a urea compd., amine salts, anilide compds. etc., with particulates, such as magnetic material particles and nonmagnetic particles, together with the binder to prepare a coating liquid. The coating liquid is applied to form the layer, by which the magnetic recording medium having the high mildew-proofing property is obtd.
|
