Kao Corporation

Hiroto Hayashi

Shoichi Murata

Tomohide Yoshida

Motomu Shibata

The present invention relates to a process for producing a toner for development of electrostatic images, including step (1): subjecting a polyhydric alcohol component and a polycarboxylic acid component to polycondensation reaction in the presence of a hydroxy group- or carboxy group-containing hydrocarbon wax (W1) to obtain a non-crystalline resin (A) containing a constitutional component derived from the hydrocarbon wax (W1) and also containing a polyester moiety; step (2): dispersing the non-crystalline resin (A) obtained in the step (1) in an aqueous medium to obtain an aqueous dispersion of resin particles (X); step (3): aggregating the resin particles (X) obtained in the step (2) in an aqueous medium in the presence of a crystalline polyester (B) to obtain aggregated particles; and step (4): coalescing the aggregated particles obtained in the step (3).

Method for producing toner for developing electrostatic image

The present invention relates to a process for producing a toner for development of electrostatic images, including the following steps (1) to (3): Step (1): aggregating resin particles (X) containing a composite resin that contains a segment constituted of a polyester resin (a) obtained by polycondensing an alcohol component containing 80 mol % or more of a propyleneoxide adduct of bisphenol A and a polycarboxylic acid component, and a vinyl-based resin segment containing a constitutional unit derived from a styrene-based compound, in an aqueous medium, to obtain aggregated particles (1); Step (2): aggregating the aggregated particles (1) obtained in the step (1) with resin particles (Y) containing a polyester resin (b) obtained by polycondensing an alcohol component containing 80 mol % or more of an ethyleneoxide adduct of bisphenol A and a polycarboxylic acid component to obtain aggregated particles (2); and Step (3): coalescing the aggregated particles (2) obtained in the step (2).

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Wakayama, Japan

Hiroto Hayashi