METHOD FOR PRODUCING MAGNETIC COATING MATERIAL AND MAGNETIC RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a magnetic coating material containing ultrafine magnetic particles in uniformly dispersed state and obtain a magnetic recording medium having excellent high-density recording property and produced by using the magnetic coating material produced by the method. SOLUTION: The method for producing of the magnetic coating material containing magnetic powder having an average particle diameter of <0.1μm and a binder resin comprises the combination of a step to carry out dispersion by using a dispersion medium and a step to perform ultrasonic dispersion and the repetition of the combined process twice or more. This invention further provides the magnetic recording medium such as a magnetic tape and a magnetic disk produced by using the magnetic coating material obtained by the production method. COPYRIGHT: (C)2005,JPO&NCIPI