ROUGH ELECTRICALLY INSULATING FOIL OF POLYPROPYLENE, AND PROCESS FOR PRODUCING IT

摘要

Disclosed is a film for use in the field of electrical insulation comprising a biaxially stretched rough polypropylene film comprising a plurality of first zones of high roughness, the first zones having a relatively high number of alpha -crystallites; and a plurality of second zones of substantially lesser roughness, the second zones having a substantially lesser number of alpha -crystallites than the first zones, the first zones being adjacent to the second zones and the adjacent first and second zones forming fine channels between each other. Also disclosed is a method for producing this film.