Dielectric film and process for producing same.

摘要

The dielectric film having improved electrical and optical properties comprises a vinylidene fluoride polymer formed essentially from vinylidene fluoride, said film having a predominant α-crystal structure, the molecular axes in the crystal region of the film being oriented mainly parallel to the plane of the film, the degree of orientation π being from 0.8 to 1.0, and the film, when heated from room temperature up to about the melting point, manifesting no heat shrinkage. The dielectric film is produced by an inflation method in which the vinylidene fluoride polymer is flow-oriented in a molten state, cooled to solidify and then taken up.