Method for producing aqueous dispersion of thermoplastic resin microparticles and toner for electrophotography

摘要

The present invention provides a method for producing an aqueous dispersion of thermoplastic resin microparticles containing considerably less residual solvent remaining in resin particles, and a toner for electrophotography containing considerably less residual solvent. A self-water-dispersible thermoplastic resin is swollen using an organic solvent having a boiling point lower than 100° C., which does not dissolve but can swell the self-water-dispersible thermoplastic resin, to produce a swollen material and the resulting swollen material is dispersed into an aqueous medium in the form of microparticles to produce an initial aqueous dispersion, and then the organic solvent is removed from the initial aqueous dispersion to prepare a dispersion. A toner for electrophotography contains microparticles obtained by separating microparticles of the self-water-dispersible thermoplastic resin from the aqueous dispersion of thermoplastic resin microparticles and drying the microparticles.