| 摘要 |
PURPOSE:To obtain a magnetic recording medium retaining high corrosion resistance against high temp. and high humidity, and rust resistance, by forming a thin film of ferromagnetic metal on a polyester film contg. amount of free org. acid not exceeding a specified value. CONSTITUTION:A ferromagnetic thin film is formed by the vapor deposition, ion plating, or the like method on a polyester film so as to control a content of free org. acid in the film, consisting mainly of formic and acetic acids produced during production to <=10<-3>g/g of magnetic recording medium, thus permitting rusting of the magnetic thin film to be prevented even in high temp. and high humidity. |
