Solid electrolytic capacitor, method for producing the same and solution for solid electrolytic capacitor

A solution for a solid electrolytic capacitor, which is used for forming a solid electrolyte layer of a solid electrolytic capacitor,

• the solution for a solid electrolytic capacitor comprising at least
• (1) a conductive complex (a) of a cationized conductive polymer and a polymer anion,
• (2) a first hydroxy compound (b) having four or more hydroxy groups,
• (3) a second hydroxy compound (c) having an amino group and one or more hydroxy groups, and
• (4) a solvent (e),
• wherein the content of the conductive complex (a) is 1 to 2% by mass, is less than that of the first hydroxy compound (b) and greater than that of the second hydroxy compound (c).

A method for producing a solid electrolytic capacitor, wherein the solid electrolytic capacitor is obtained by winding a porous anode foil having a dielectric layer formed thereon and a cathode foil together with separators having a solid electrolyte supported thereon, which separators are interposed between the foils,

• wherein the solid electrolyte layer comprises at least
• (1) a conductive complex (a) of a cationized conductive polymer and a polymer anion,
• (2) a first hydroxy compound (b) having four or more hydroxy groups,
• (3) a second hydroxy compound (c) having an amino group and one or more hydroxy groups, and
• (4) a solvent (e), and
• the solid electrolyte layer is formed by applying a solution, in which the content of the conductive complex (a) is less than that of the first hydroxy compound (b) and greater than that of the second hydroxy compound (c), and then drying.