| 摘要 |
PROBLEM TO BE SOLVED: To provide a method capable of efficiently producing magnetic paint in which ultra-fine particulate magnetic powder is satisfactorily dispersed, and a method for manufacturing a magnetic recording medium suitable for a high density recording operation by using the obtained magnetic paint. SOLUTION: In the case that the dispersion of the magnetic paint is carried out by using a dispersing apparatus of a medium dispersion type, the dispersion is carried out so as to satisfy the following equation (3) by using a dispersing medium satisfying the following equations (1) and (2) as the dispersion medium. The obtained magnetic paint is applied to a flexible support, then a magnetic field orientation process, drying process and calender process are carried out to make up the magnetic recording medium. Equations are: (1) 0.02≤d≤0.3, (2) 300≤D/(ρb<SP>-0.75</SP>×d<SP>0.5</SP>)≤900, (3) 0.02≤η/ [(ρb-ρp)×d<SP>2</SP>×v<SP>2</SP>]≤0.1, where letters show as follows, D: the average long axis length (nm) of magnetic powder, d: the average particle diameter (mm) of dispersing medium,ρb: the density (g/cm<SP>3</SP>) of the dispersing medium,ρp: the density (g/cm<SP>3</SP>) of the magnetic paint to be dispersed,η: the viscosity (Pa s) of the magnetic paint to be dispersed, v: the circumferential velocity (m/s) at the rotational tip of an agitation means. COPYRIGHT: (C)2005,JPO&NCIPI
|
