SUBSTANCE CAPABLE OF ACTING AS OXIDIZING AGENT AND DOPANT FOR SYNTHESIS OF ELECTRICALLY CONDUCTIVE POLYMER, ALCOHOL SOLUTION THEREOF, ELECTRICALLY CONDUCTIVE POLYMER, AND SOLID ELECTROLYTE CAPACITOR

摘要

[PROBLEMS] To provide: a substance capable of acting as both of an oxidizing agent and a dopant, which does not produce any precipitation for a certain period of time or longer even when prepared into an alcohol solution, and has a mild oxidizing power; an electrically conductive polymer having high electrical conductivity and excellent heat resistance, which is produced by using the substance; and a solid electrolyte capacitor having high reliability under high temperature conditions, which is produced by using the electrically conductive polymer. [MEANS FOR SOLVING PROBLEMS] A substance capable of acting as both of an oxidizing agent and a dopant comprises a ferric salt of an acid component comprising a benzenesulfonic acid derivative and sulfuric acid, wherein the benzenesulfonic acid derivative is represented by the general formula (1) [wherein R represents an alkyl or alkoxy group having 1 to 4 carbon atoms], and wherein a type of the benzenesulfonic acid derivative having the R group and the SO3H group located in para-position relative to each other in the benzene ring makes up 90 mol% or more of the entire amount of the benzenesulfonic acid derivative. The substance has a sulfuric acid content of 0.05 to 1.5 mass% relative to the entire amount of the acid component, a total inorganic alkali content of 300 ppm or less and a total organic alkali content of 0.01 mol% or less, and shows a pH value of 1.5 to 3.0 when prepared into an 8 mass% aqueous solution. An electrically conductive polymer is synthesized by using the substance. A solid electrolyte capacitor is produced by using the electrically conductive polymer as a solid electrolyte.