MAGNETIC RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To improve a productivity and running characteristics by a method wherein a specific relation between the bending rigidity in the longitudinal direction of a recording medium which is composed of a supporter and a magnetic layer containing lubricant and formed into a tape-shape and the extracted quantity of the lubricant after the immersion in methanol under specific conditions is satisfied. SOLUTION: A relation between a bending rogidity value T (mgf) and the extracted quantity L (mg/126.5 cm<2> ) of lubricant after the immersion in methanol at 25 deg.C for 1 minute satisfies a formula: 0<(T- 32)×(L+0.036)<100. An intermediate layer 3 containing magnetic powder and/or nonmagnetic powder whose Mohs' hardness is not smaller than 4 is provided between a magnetic layer 4 and a supporter 2. It is recommended that the material of the intermediate layer 3 is polyurethane resin whose tanδpeak temperature is 10-70 deg.C and which contains for 100 wt.pt. of the magnetic powder at least 2-50 wt.pt. of one of carbon powder whose primary particles have average particle diameter of 10-60 nm and a bulk density of 50-800 g/l and polyurethane resin whose number- average molecular weight is 10,000-50,000.