| 摘要 |
PROBLEM TO BE SOLVED: To prevent the rapid lowering of capacity, the rising of tanδ, or the like under revere environment such as high temperature, high humidity, etc., by providing a coating layer having a specific thickness on the surface of a polyester film, and specifying the variation rate of glossiness at the time of setting a metal layer on the coating layer. SOLUTION: A coating layer with a thickness of 0.01-1μm is formed on at least one surface of a polyester film, the glossiness is made G0 as a metal layer is set on the coating layer, and a value of the variable rate (G0 -G)/G0×100(%) is made 20% or lower when the glossiness is made G after being immersed in methylethyl ketone for 10 mins. When the value comes beyond 20%, tanδor the like gets worse. The coating layer made by applying and drying water soluble and/or water dispersive cross-linked polyester resin, and/or water soluble and/or water dispersive cross-linked polyester urethane resin is preferable at giving an anti-moisture heat life and chemical resistant property. |
