METHOD OF DETERMINING COATING CONDITION IN MANUFACTURING OF MAGNETIC RECORDING MEDIUM AND MAGNETIC RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To obtain a good magnetic layer surface in coating because the flocculation of magnetic particles of a magnetic coating liquid can be suppressed and destroyed in coating the magnetic coating liquid by an extrusion type coating method. SOLUTION: In forming the magnetic layer of a single layer on the surface of a web 12 by applying the magnetic coating liquid 20 prepared by dispersing the magnetic particles into a solvent on the web by using the extrusion type coating method, the coating conditions are evaluated by the shearing energy E per unit volume of the magnetic layer determined by the equation E=μ*L*V/4*t<2> when the viscosity at a shearing speed 10<5> sec<-1> of the coating liquid 20 is defined as [Pa.scd], the length on the surface facing the web on the downstream side of a slit at the front end of a coating head as L[m], the traveling speed of the web 12 as V and the wet coating thickness of the magnetic layer as t[m] and the coating conditions are determined in accordance with the result of this evaluation.