Magnetic recording media comprising carbon black-adsorbed metal oxide particles in a magnetic recording layer

Claim 1

A magnetic recording medium comprising a support, and a magnetic recording layer formed on at least one side of said support, said magnetic recording layer being made of a dispersion, in a resin binder, of magnetic particles and non-magnetic particles of a carbon black-adsorbed metal oxide which is selected from the group consisting of aluminum oxide in an amount of 0.5 to 30 wt% of the magnetic particles, titanium dioxide in an amount of 0.5 to 30 wt% of the magnetic particles, chromium (III) oxide in an amount of 0.5 to 15 wt% of the magnetic particles, and mixtures thereof, wherein, when the particles are mixtures of carbon black-adsorbed titanium dioxide and carbon black-adsorbed aluminum oxide, they are present in the total amount of 0.5 to 30 wt% of said magnetic particles; when the particles are mixtures of carbon-black adsorbed titanium dioxide and carbon-black adsorbed chromium (III) oxide, they are used in the total amount of 0.5 to 30 wt% of said magnetic particles provided that said chromium (III) oxide is used in an amount from 0.5 to 15 wt%; and when the particles are mixtures of particles of carbon black-adsorbed aluminum oxide and carbon black chromium (III) oxide, they are used in the total amount of from 0.5 to 30 wt% of said magnetic particles provided that said chromium (III) oxide is used in an amount of from 0.5 to 15 wt%, and wherein said carbon black powder has an average size below 100 millimicrons and a surface area of above 30 m 2 /g and is adsorbed in an amount of from 0.5 to 20 wt% based on the weight of the non-magnetic metal oxide particles.