PURPOSE: To improve the wear resistance of a magnetic layer, the wear resistance of a magnetic head and the smoothness of a tape surface by providing a magnetic layer consisting of contg. inorg. powder of ≤2μm average grain size and ≥5 Mchs hardness obtd. by mixing by a dry process under the condition of ≥1G impact value and magnetic powder in the presence of an arom. carboxylic acid and/or silicone dispersant.
CONSTITUTION: The particle size of inorg. powder is essentially ≤2μm and more preferably ≤1.5μm average grain size. The reinforcing material has good dispersibility as a dispersant having affinity to a toluene solvent is thickly and securely press-adhered to the surface of the inorg. powder. The reinforcing material having excellent dispersibility into an org. solvent, above all, toluene or a polymer is thus obtd. The reinforcing material is added to the magnetic powder at generally 0.1W15wt%, more preferably 0.5W10wt%. If the reinforcing material is added at 0.1wt% or below, the wear resistance of the magnetic layer decreases and if said material is added at ≥15wt%, the wear of the magnetic head increases and therefore the addition at such a rate is undesirable.
UMEZAKI HIROSHI
MURAKAMI HIDEAKI
