MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To improve characteristics by a combination of a binder contg. a vinyl chloride/vinyl acetate copolymer having a sulfonic acid group or the salt thereof and a dispersant contg. a surface active agent having the sulfonic acid group or the salt thereof. CONSTITUTION:The binder for magnetic powder contains at least the vinyl chloride/vinyl acetate copolymer contg. the sulfonic acid group or the salt thereof as one component and has the better dispersibility for the magnetic powder than other binders. The effect of improving the dispersibility of the magnetic powder is improved by the synergistic effect with the binder only when the surface active agent having the sulfonic acid group or the salt thereof is used as the dispersant together with the above-mentioned binder. More specifically, even if such specific binder is used, the synergistic effect is not obtainable into the case in which the surface active agent having functional group exclusive of the sulfonic acid group or the salt thereof is used in combination. The improvement in the magnetic characteristics and electromagnetic conversion characteristic is made possible by such combination of the specific binder and specific dispersant.