| 摘要 |
PURPOSE:To improve abrasion resistance, SN ratio, and reproduction output, by coating a base with a magnetic coating material contg. a ferromagnetic powder treated with a specified compound solution, and an epoxy resin and polyurethane as a binder. CONSTITUTION:A surface-modified magnetic powder is obtained by treating Fe- Co-Ni magnetic alloy powder in a toluene soln. of a compound represented by formulaIin which R1, R2 are alkyl, alkenyl, or fluorinated alkyl, M is an alkali metal, ammonium, tetramethyl ammonium, or methylpyridinium, and (n) is 0 or 1. A magnetic coating material is prepared by dissolving or dispersing 90pts.wt. of this powder, 16pts.wt. epoxy resin, 7pts.wt. polyurethane, 3pts.wt. carbon black, and 3pts.wt. silicone oil in a ketone type solvent. One side of a polyethylene film is coated with this coating material while a magnetic field is applied, and dried to form a magnetic tape serviceable as a magnetic recording medium improved in abrasion resistance and SN ratio. |
