Toner for the development of electrostatic image and process for the preparation thereof

摘要

Disclosed is a process for preparing a particulate toner for developing an electrostatic image, which comprises suspending a polymerizable monomer composition comprising a polymerizable monomer, a resin dissolved therein, and a coloring agent in an aqueous medium not containing a dispersant to prepare a pre-suspension, jetting the pre-suspension through a nozzle under elevated pressure in a flowing direction which is forced to vary so that the pre-suspension collides with a predetermined plane or with each other, and then immediately passing the pre-suspension through an apparatus for throttling the path to produce back pressure and shearing stress to prepare a suspension containing a particulate polymerizable monomer and subjecting the resulting suspension to polymerization. The toner prepared by the process is a high performance toner which is free of finely divided grains and emulsion, exhibits a high chargeability, a uniform chargeability distribution, an excellent environmental stability and a high definition, and is insusceptible to fogging and unevenness.