MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To enable increase in the packing density of magnetic powder and to improve a magnetic characteristic by constituting a primer coating layer of a nonmagnetic substrate of a blank material contg. a thermosetting polyurethane resin and thermosetting polyester resin. CONSTITUTION:A mixture composed of a polyurethane resin of a thermosetting type and polyester resin of a thermosetting type is used as a blank material for a primer coating layer. The polyurethane resin of a thermosetting type is hardly soluble in an org. solvent used for a magnetic paint and is made more hardly soluble when thermoset. The adhesion to the base film is much improved by using the polyester resin of a thermosetting type. The component content of the binder in the magnetic layer is thus relatively decreased and the packing density of magnetic powder is increased.