VERTICALLY ORIENTED MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To obtain a superior high density magnetic recording medium in a short time with a solventless magnetic coating material contg. magnetic powder and a binder in a specified ratio by curing the binder in the coating material coated on a substrate by irradiating electron beams in a state in which the anisotropic axes of the particles of the magnetic powder are vertically arranged on the surface of the substrate. CONSTITUTION:A magnetic coating material 11 is coated on a substrate 1 such as a polyethylene terephthalate film while sending the substrate 1 from a guide roll 5 to a guide roll 6 along the mirror finished surfce of a drum 4 rotating in the direction of an arrow. The coating material 11 contains 40-60wt% solventless binder having proper viscosity and 60-40wt% magnetic powder. The binder is made of a mixture of a resin such as polyurethane modified with (meth)acrylic groups with a monomer such as allyl acrylate. After coating the coating material 11, the binder in the material 11 is cured by irradiating electron beams (b) in a state in which the anisotropic axes of the particles of the magnetic powder 3 are vertically arranged on the surface of the substrate 1 with a magnetic field applier 9 to form a magnetic layer 2. A superior high density magnetic recording medium is obtd. in a short time without requiring a solvent drier.