| 摘要 |
PURPOSE:To improve the dispersibility of magnetic powdery particles and to obtain the title magnetic recording medium having excellent squareness ratio, surface characteristic and durability by incorporating a specified polymer into the magnetic recording medium. CONSTITUTION:At least one kind of polymer selected from a polymer of a higher alkyl ester of acrylic acid, a polymer of a higher alkyl ester of methacrylic acid and a coplymer of a higher alkyl ester of acrylic acid and a higher alkyl ester of methacrylic acid is incorporated into a magnetic recording medium. The polymer having 100-3,000 mean polymerization degree is preferably used. When the polymer and magnetic powdery particles are mixed along with a suitable binder, a magnetic recording medium coating material wherein the magnetic powdery particles are uniformly dispersed in the primary particles can be obtained. Accordingly, the coating material is coated on a suitable substrate and dried by volatilizing the solvent. Consequently, a magnetic recording medium layer having excellent squareness ratio, rigidity and wear resistance, wherein ageing deterioration such as blooming is not caused even under severe conditions and hence having excellent durability can be obtained.
|
