Conductive polymer, and method for its manufacture, conductive polymer dispersion and solid electrolytic capacitor and methods for their preparation

The present exemplary embodiment provides a conductive polymer having high conductivity and a method for its production and a conductive polymer dispersion, and further provides a solid electrolytic capacitor having low equivalent series resistance (ESR) and a method for its preparation. A conductive polymer is prepared by a method comprising the steps of: dissolving a sulfonic acid resin having a weight average molecular weight of at least 2000 and at most 50,000 and represented by the following formula (1) compound represented in a solvent; Mixing at least one of pyrrole, thiophene and derivatives thereof selected monomer in a resulting solution; Performing a chemical oxidative polymerization of the monomer using a persulfate, to obtain a conductive polymer; To the given and washing of the conductive polymer in the conductive polymer to remove the compound represented by the formula (1). C wherein n is an integer from 3 to 6.