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.
本发明提供了一种生产热塑性
树脂微粒
水分散液的方法,该分散液中残留在
树脂微粒中的残留溶剂大大减少,本发明还提供了一种用于电子照相的墨粉,该墨粉中残留的溶剂也大大减少。使用沸点低于 100°C 的有机溶剂对自
水分散性热塑性
树脂进行溶胀,该有机溶剂不会溶解但可以溶胀自
水分散性热塑性
树脂,从而产生溶胀材料,并将产生的溶胀材料以微颗粒的形式分散到
水介质中以产生初始
水分散液,然后从初始
水分散液中去除有机溶剂以制备分散液。用于电子照相的调色剂含有从热塑性
树脂微粒的
水分散液中分离出自
水分散热塑性
树脂微粒并将其干燥后得到的微粒。