| 摘要 |
PURPOSE:To obtain a film having excellent electromagnetic conversion characteristics and slipping property when provided with a magnetic layer on its surface, by preparing the thin-layer of thin-membrane forming material which reduces the roughness of film surface to a specific centerline average roughness of surface (Rap) on the surface of polymeric film having a specific centerline average roughness of surface (Rao). CONSTITUTION:A polymeric film 1 is made of, for example polyester, polyamide, polyamideimde etc., particularly polyester is preferable. A thin-membrane forming material 2 is polyester, polyurethane, acrylic resin, polyester and the fine particles of silicon oxide, polyurethane and the fine particles of silicon oxide etc. and they are preferably used as aqueous liquid. The thin-layer of this thin-membrane forming material is prepared on the surface of the polymeric film 1 having Rao 0.005-0.5mum, then the roughness of the surface is reduced to Rap 0.001-0.05mum. The reduction of this roughness of the surface is easily achieved by satisfying the following expression I concerning the relation of Rao and the quantity P of the thin-layer. |
