Interaction of magnetic particles with recording media formulation components

摘要

The interaction of commercially available, iron based magnetic particles with certain particulate media formulation components was investigated using the technique of flow microcalorimetry. The heat of wetting of these particles by solvents was found to be a function of the solvent dipole moment, particle coercivity and surface area. Di(2-ethyl hexyl) phosphoric acid, a model dispersant, appeared to interact chemically with an iron particle of high coercivity. Solvent basicity influenced the heat and extent of interaction of the dispersant. Characterization of the interaction of a vinyl acetate-vinyl chloride copolymer that combined the functionality of a dispersant and a binder was also carried using the techniques of calorimetry and X-ray photoelectron spectroscopy.