| 摘要 |
PURPOSE:To improve the binding property with binder, dispersing property and wear-resisting property, by coating the surface of magnetic powder with an alkanolamide non-ionic surface active agent. CONSTITUTION:The magnetic powder is immersed in an aqueous solution containing the alkanolamide non-ionic surface active agent. The magnetic powder and the aqueous solution are stirred together and then filtered. Thereafter, the magnetic powder is dried. The adsorption of the surface active agent is made firm by a heating treatment during the drying. For example, the alkanolamide non-ionic surface active agent is represented by the structural formula. The magnetic powder i s kneaded together with a binder, thereby preparing magnetic paint. The magnetic paint is coated on a polyester substrate film, thereby obtaining a magnetic tape. The change in the quality of the alkanolamide non-ionic surface active agent due to drying is low. The surface active agent has a high affinity to the magnetic powder and the binder. Thereby, the dispersing property and binding property are improved. |
