MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To provide a magnetic recording medium having a layer such as a magnetic layer which has excellent tackiness, wear resistance, durability and surface characteristic and is substantially low in both surface electric resistance and light transmittance by forming a layer incorporated therein with soft polyurethane and hard polyurethane having tensile strength and breaking elongation within a specific range and carbon black having a specific surface area within a specific range. CONSTITUTION:Soft polyurethane and hard polyurethane can be synthesized by the reaction between polyol and polyisocyanate. Both polyurethanes may be used in combination at an optional ratio and it is verified that there is a specified preferable range in the respective contents thereof. The ratio of the soft polyurethane to the hard polyurethane by weight is preferably 80:20-20:80 in terms of still durability and more preferably 70:30-30:70. A magnetic recording medium is formed by laminating an undercoating layer 2 and a magnetic layer 3 on a non-magnetic base 1. The soft polyurethane, the hard polyurethane, light shieldable carbon black CB1 having 40m<2>/g/g specific surface area (BET value) B1 and conductive carbon black CB2 having 200m<2>/g<=B2<500m<2>/g specific surface area (BET value) B2 are incorporated respectively by prescribed contents in the layer 3.