PURPOSE: To improve stability with age and durability by incorporating a polycarbonate polyurethane resin into a magnetic layer, specifying the Young's modulus thereof within a specific range and confining the surface roughness to ≤0.05μm.
CONSTITUTION: This magnetic recording medium is constituted by providing the magnetic layer dispersed with fine ferromagnetic powder in a binder on a nonmagnetic base. The polycarbonate polyurethane resin is incorporated at 30W60pts.wt. into this magnetic layer, a vinyl chloride/vinyl acetate resin at 15W35pts.wt. and polyisocyanate at 20W40pts.wt., by which the Young's modulus of the magnetic layer is kept within the 2×104W50×104kg/cm2 range at -10W60°C. The surface roughness is confined to the smoothness of ≤0.05μm (0.25mm cut off value). The output is thereby improved and the self-adhesive strength at and under a high temp. and high humidity, coefft. of friction, powder dislodgment and still durability are simultaneously improved.
NAKAGAWA ATSUSHI
HASUMI KAZUO
KAWAMATA TOSHIO
| JPS61222027A | 1986-10-02 | |||
| JPS619830A | 1986-01-17 |