Magnetic recording material prodn. using imidazoline cpd. dispersant - giving increased packing density and remanent magnetisation

摘要

Prodn. of a magnetic-recording material involves dispersing finely-divided magnetically anisotropic material and usual additives in a soln. of a polymeric binder in an organic solvent, applying it to an unmagnetisable substrate, aligning the magnetic material with a magnetic field and drying and/or hardening. Improvement is that a 2-imidazoline cpd. of formula (I) (where R is 2-20C linear or branched (un)satd. hydrocarbyl; Y is OH or amino) is added as dispersant. The packing density of the particles and hence the remanent magnetisation are increased.