Patent ID: 7859828

Claim:
An electrolytic solution for electrolytic capacitor comprising a capacitor element and a casing containing said capacitor element, said capacitor element including a pair of electrodes composed of an anode chemical foil and a cathode foil, and a p-type doping conductive separator (E′) which is formed with a p-type doping conductive polymer layer (F′) containing a p-type dopant agent (H′) on its surface and is interposed between said pair of electrodes, said p-type doping conductive separator (E′) and said pair of electrodes being rolled up in an overlapped state with each other, and spaces between said pair of electrodes being impregnated with the electrolytic solution for electrolytic capacitor, wherein said electrolytic solution for electrolytic capacitor contains a component (A 0 ), which is at least one member selected from the group consisting of perbenzoic acid and mono perphthalic acid, having reduction potential of −1.6 to 0V when measured in the following measuring method: a method for measuring the reduction potential: into γ-butyrolactone into which tetraethylammonium fluoroborate is dissolved at 0.23 mol/L as a supporting electrolyte, a component (A 0 ) is dissolved at 0.1 mol/L, and the potential thereof is measured at the time when the current at −0.2 μA flowed by means of the convective cyclic voltammetry measuring method using a Grassi carbon electrode (φ 1.0 mm) as an active electrode, a (Ag/Ag + ) electrode as a reference electrode, and a platinum electrode as a counter electrode.