Patent ID: 8729217

Claim:
A semi-conductive polyimide film having: a common logarithm of a surface resistivity at 25° C. and 60% RH of 9 to 15 log Ω/square; a common logarithm of a volume resistivity of 8 to 15 log Ω·cm; a fatigue stress in accordance with a fatigue test complying with JIS K7118, upon a number of repetition being 10 7 , of 160 MPa or more; and a number of durable bending in accordance with an MIT test complying with JIS P8115of 2,000 times or more; wherein the semi-conductive polyimide film is obtained from a polyamide acid solution comprising at least one of a copolymer comprising a repeating unit of: a component A in which a fully aromatic skeleton which is a tetracarboxylic acid residue of 3, 3′, 4, 4′-biphenyltetracarboxylic acid dianhydride (BPDA) and a p-phenylene skeleton which is a diamine residue are bound by an imide bond; and a component B in which a fully aromatic skeleton which is a tetracarboxylic acid residue of 3, 3′, 4, 4′-biphenyltetracarboxylic acid dianhydride (BPDA) and a diphenylether skeleton which is a diamine residue are bound by an imide bond; and a blend of a polymer comprising the component A as a repeating unit and a polymer comprising the component B as a repeating unit, wherein a composition molar ratio of the component A and the component B (A/B) is 7/3 to 3/7; and the semi-conductive polyimide film comprises at least one conductive agent in an amount of 5 to 30 wt %.