Magnetic recording material contg. silica particles - of specified dimensions in the magnetic layer, usable at high temp. and humidity

摘要

A magnetic recording material is prepd. by appln. of is not 1 layer of a dispersion onto a non-magnetic carrier and converting the layer into a hard magnetic layer of predetermined thickness. The dispersion contains (a) a finely divided magnetic powder and (b) dispersed SiO2 with particle dimensions of ratio 6-8:2.5-4:1, and with average particle size corresp. to the thickness of the magnetic layer, in (c) a soln. of an organic polymeric binder in an organic solvent. The dispersion may also contain the usual additives. The material has high mechanical strength, and shows no increase in friction between the magnetic layer and the magnetic head at high temp. and humidity. Deposition of material on the head is avoided.