| 摘要 |
PURPOSE:To provide superior rust preventiveness, still stability and wear resistance by coating ferromagnetic powder with cross-linked polyamide resin formed by hardening or cross-linking polyamide resin having reactive functional groups with a hardening agent having a group which can react with the functional groups. CONSTITUTION:Polyamide resin having functional groups is stuck to or allowed to be adsorbed on the surface of ferromagnetic powder, and the powder is immersed in a hardening agent having a group which can react with the functional groups to harden or cross-link the polyamide resin film on the surface of the ferromagnetic powder with the hardening agent. The ferromagnetic powder to be incorporated in a magnetic layer is magnetic powder of a metallic oxide such as gamma-Fe2O3, Co-deposited gamma-Fe2O3 or Fe3O4 or magnetic metallic powder of Co- Ni-P, Fe-Co-Ni, Fe-Ni or the like. Said polyamide resin is a compound represented by the general formula (where each of X<1>, X<2> and X<3> has H, OH, amino, alkyl, carboxyl, alkenyl or aryl, and at least one among them has a reactive functional group). |
