Patent ID: 7105620

Claim:
A chemical polymerization process for preparing an aqueous dispersion of a copolymer of at least one 3,4-alkylenedioxythiophene compound with a solubility in water at 25° C. of less than 2.2 g/L with at least one 3,4-alkylenedioxythiophene compound with a solubility in water at 25° C. of at least 2.2 g/L and a polyanion comprising the steps of: (i) providing a solution of a polyanion; (ii) adding a 3,4-alkylenedioxythiophene compound with a solubility in water at 25° C. of less than 2.2 g/L and a 3,4-alkylenedioxythiophene compound with a solubility in water at 25° C. of at least 2.2 g/L to the solution provided in step (i); and (iii) adding an oxidizing or reducing system to the mixture provided in step (ii).