Abstract
Magnetic paint was produced by using magnetic powder subjected to inorganic or organic surface treatments, in order to make clear the influence of surface treatment exerted on the state of kneading and dispersion. The change of surface characteristic of magnetic powder was estimated from the heat of wetting for organic solvents and the amount of binder absoption. Also, the influences of the degree of surface treatment, water ratio of magnetic powder and the solubility parameter of organic solvent were studied.
The state of kneading and dispersion of magnetic powder was evaluated by measuring the mixing torque, glossiness and magnetic recording properties of coated videotape.
From the results, the effect of surface treatment for obtaining the well-dispersed state of magnetic powder was clarified.
