POLYIMIDE FILM, METHOD FOR PRODUCING THE SAME, POLYIMIDE FILM ROLL AND METHOD FOR PRODUCING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a polyimide film holding heat resistance and flexibility at higher levels without causing warpage of the film for heat. SOLUTION: The polyimide film is obtained as follows. A solution containing a precursor of the polyimide having a biphenyltetracarboxylic acid residue as a residue of at least aromatic tetracarboxylic acids and a phenylenediamine residue as a residue of aromatic diamines in an organic solvent is cast and applied onto a support to form a coated film. The resultant coated film is dried by heating so as to afford≤5 difference in imidizing ratios on one surface side and the other surface side of the obtained precursor film. The resultant precursor film is then heat-treated to provide the polyimide film. The obtained polyimide film is wound into a roll shape with≥100 N winding tension so as to provide a radius of curvature within the range of 30-600 mm with the surface A of the resultant film as the winding inside. Thereby, a polyimide film roll is obtained. The resultant polyimide film roll is composed of the polyimide film having≤10% degree of curling after heat treatment at 300°C and≤25% coefficient of variation (CV%) of the coefficient of linear expansion. COPYRIGHT: (C)2007,JPO&INPIT