MULTILAYERED ENDLESS TUBULAR POLYIMIDE FILM AND METHOD FOR MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a multilayered endless tubular polyimide film comprising at least two layers based on a polyimide resin and having stable electrostatic capacity. SOLUTION: The multilayered endless tubular polyimide film is composed of a semiconductive polyimide layer made semiconductive by conductive carbon black and a substantially electric insulating polyimide layer, and the electrostatic capacity thereof is 50-500 pF/cm2 and the irregularity thereof is±20%. This film is effectively used as a paper feed and transfer film or intermediate transfer film of a color copier. The film is effectively manufactured by three processes wherein two kinds of molding raw liquids are respectively supplied into a rotary drum substantially generating no centrifugal force in an atomized state to be heated and the formed two layers are imidated by hot air heating. Herein, especially, the residual amount of an organic solvent in the first process is preferably set to 20% or less.