Magnetic recording medium used for audio tape, video tape, computer tape and discs in both analogue and digital systems comprises a non-magnetic carrier and a magnetic layer containing ferromagnetic metal particles and a binder resin

摘要

Magnetic recording medium comprises a non-magnetic carrier and a magnetic layer containing ferromagnetic metal particles mainly of iron and having a spindle form with an average main axis length of 0.15 microns m or less and a binder resin, and optionally an adhesion promoter layer or a non-magnetic layer containing non-magnetic inorganic particles and a binder between the carrier and the magnetic layer. The average middle line roughness Ra of the surface of the magnetic layer is 2-6 nm. The medium has a steel ball wear at 23 deg C and 70 % relative moisture of 2 x 10-5 - 4 x 10-5 mm3, and a friction coefficient of 0.2-0.3 between the surface of the magnetic layer and an SUS bar having a roughness of 8-10 nm. Preferred Features: The average main axis length of the ferromagnetic metal particles is 0.05-0.15, preferably 0.05-0.12 microns m.