abstract |
Disclosed is a polyimide film that exhibits high resistance to repeated bending and repeated twisting. A polyamide obtained from diamines containing 50 mol% or more of paraphenylenediamine and tetracarboxylic acid anhydrides containing 50 mol% or more of 3,3'-4,4'biphenyltetracarboxylic dianhydride. Using a process in which an acid is applied to a support and dried and then subjected to tensile deformation between the crystallization start temperature obtained by using high-power X-ray diffraction and the 90% imidation ratio attainment temperature obtained from IR measurement. By performing the imidization treatment, a polyimide film having high repeated bending resistance and repeated twisting resistance is obtained. [Selection figure] None |