Loading patent…
AssigneeDowa Electronics Materials Co., Ltd.
InventorsShinichi Konno, Kenichi Inoue, Toshihiko Ueyama, Ken Inoue
Estimating the term…
A nonmagnetic powder, used for the nonmagnetic layer of a coated type magnetic recording medium having a multilayer structure, has good dispersibility in the binder in which it is dispersed to prepare a coating material that is applied to the nonmagnetic layer. The nonmagnetic powder has an iron compound as its principal component and exhibits a maximum pore volume value in a pore diameter range of 0.01 μm to 0.05 μm within a pore diameter range of 0.0018 μm to 0.1 μm in which the relationship between pore diameter and pore volume is calculated by a mercury injection method. The nonmagnetic powder exhibits a cumulative pore volume value in a pore diameter range of 0.0018 μm to 0.01 μm that is not more than 30% of the cumulative pore volume value in the pore diameter range of 0.0018 μm to 0.1 μm.
Nonmagnetic powder for a magnetic recording medium that has an iron compound as its principal component and exhibits a maximum pore volume value on a curve of a pore diameter range of 0.01 μm to 0.05 μm plotted on a graph in which a horizontal axis is pore diameter from 0.0018 μm to 0.1 μm and a vertical axis is the pore volume corresponding to the pore diameter, in which a relationship between pore diameter and pore volume is calculated by a mercury injection method.
Dependencies are inferred from the claim text.