The behavior of lauric acid lubricant in a magnetic coating layer and its effect on mechanical properties of magnetic media

The fundamental behavior of a lubricant, lauric acid, in a magnetic coating layer is studied by means of solvent extractions. In the magnetic layer, lauric acid is shown to be present in three different states: adsorption on the surface of the magnetic particles, dissolution in the binder, and the free state at the interface. The amount of free lauric acid depends on the amounts of lauric acid adsorbed on the magnetic particles and dissolved in the binder. The runnability of the magnetic tape is found to be governed by the free lauric acid.