| 摘要 |
PURPOSE:To obtain efficiently a magnetic disc having high performance at a low cost washing a substrate with a prescribed washing liquid then providing a magnetic layer thereon. CONSTITUTION:A material which dissolves org. materials such as cutting fluid, etc. sticking on the surface of a disc substrate, for example, perchloroethylene, trichloroethylene and other defatting agents and a material which removes inorg. materials such as machining swar, salts, etc. sticking on the surface of the disc substrate, for example, an aq. soln. contg. an acid, alkali, etc. are mixed and a nonionic surface active agent in particular is added thereto to emulsify the mixture. The surface of the substrate is washed with such emulsion washing liquid and is then washed with pure water. A magnetic layer is formed on the surface of the substrate after drying. The magnetic disc having high performance is thus obtd. efficiently at a low cost. |
