| 摘要 |
PURPOSE:To provide a metal film characterized by less missing of vapor deposition films and less change in capacity by providing a vapor deposition metal layer comprising two kinds of metals on the surface of a biaxial orientation polypropylene film. CONSTITUTION:As a metal for constituting a vapor deposition metal layer, combination of at least two kinds of metals is required. As the preferable combinations of the metals, Zn/Al, Zn/Cu, Zn/Ni and the like can be listed. However, it is necessary that the ratio between the number of nitrogen atoms and the number of carbon atoms in the vapor deposition metal layer is in the range of 0.005-0.08. Furthermore, it is necessary that the ratio between the number of oxygen atoms and the number of the carbon atoms is in the range of 0.05-0.25. As a result, the surface roughness Ra of a biaxial orientation polypropylene film becomes 0.03-0.13mum. When the Ra is smaller than said range, the sliding of the film becomes extremely poor. Conversely, when the Ra is larger than said range, the decrease in capacitance of a capacitor becomes large due to the disappearance of the vapor deposition film due to corona discharge. |
