| 摘要 |
PURPOSE:To raise an S/N ratio and to improve an abrasion resistance, by coating ferromagnetic fine powder having a specified specific surface area with butyl acrylate acrylic acid compound oligomer, and dispersing it in a binder consisting of a specific component. CONSTITUTION:The surface of ferromagnetic powder whose specific surface area by a BET surface area measuring method of gamma-Fe2O3, etc. is >=30m<2>/g is coated with butyl acrylate acrylic acid compound oligomer which is <=1,500 in its number mean molecular weight, and contains 3 or less COOH radicals whose copolymerization ratio is 70-98mol% butyl acrylate and 2-30mol% acrylic acid, and the coated magnetic powder concerned is dispersed to a binder containing nitrocellulose and polyurethane resin, by which a magnetic recording medium is obtained. |
