Patent ID: 7468149

Claim:
A process for the preparation of a polyaniline dispersion, the said process comprising the steps of: a. dissolving dry polyaniline salt powder and a stabilizer separately in a first organic polar solvent and mixing the above said solutions, under stirring, at ambient conditions, to obtain a first polyaniline dispersion in an organic solvent; and either b. adding the first polyaniline dispersion of step (a) to a second polar solvent, the second polar solvent being miscible with the first polar solvent used in step (a) under stirring to obtain a second polyaniline dispersion; and (c) further adding a less polar solvent miscible with the first polar solvent used in step (a) but immiscible with the second polar solvent used in step (b), to the second polyaniline dispersion solution mixture obtained in step (b) to remove the organic polar solvent used in step (a) to obtain the desired polyaniline dispersion in the polar solvent used in step (b) OR (d) adding the first polyaniline dispersion of step (a) to a less polar solvent miscible with the solvent used in step (a) under stirring to obtain a fourth polyaniline dispersion; (e) further adding a second polar solvent, the second polar solvent being miscible with the first polar solvent used in step (a) but immiscible with the less polar solvent used in step (d) to the fourth polyaniline dispersion to remove the organic polar solvent used in step (a) to obtain a fifth polyaniline dispersion in the less polar solvent used in step (d); and (f) adding the fifth polyaniline dispersion in the less polar solvent obtained in step (e) to an organic solvent followed by evaporating the less polar solvent from the resultant polyaniline dispersion mixture to obtain the desired polyaniline dispersion in organic solvent.