Process for lowering charge/mass ratio of toner particles having controlled morphology and containing quaternary ammonium tetraphenylborate charge control agents

摘要

A process for lowering the charge/mass (Q/m) ratio of toner particles formed by limited coalescence includes: forming an organic phase containing a water-immiscible liquid, pigment, a quaternary ammonium tetraphenylborate salt, and a polymeric material selected from the group consisting of an acrylic resin, a methacrylic resin, a styrene-acrylic resin, a styrene-methacrylic resin, a polyamide, and a polyester. The organic phase is dispersed in an aqueous phase containing a solid colloidal stabilizer, and a suspension of small droplets of the organic phase is formed in the aqueous phase by high shear agitation. The water-immiscible liquid is removed from the small droplets, thereby forming a suspension in the aqueous phase of small, non-spherically shaped solid particles, which are separated from the aqueous phase and dried. The quaternary ammonium tetraphenylborate salt is included in the organic phase in an amount effective for lowering the charge/mass (Q/m) ratio of the toner particles.