Kao Corporation

Motomu Shibata

Shoichi Murata

Tomohide Yoshida

Hiroto Hayashi

Provided are a binder resin composition for toner excellent in low-temperature fusing property, storage stability and durability, a toner for developing electrostatic images that contains the binder resin composition for toner, and a method for producing the binder resin composition for toner. The binder resin composition for toner contains a resin composition (C-P) prepared by condensing an acid group-having crystalline resin (C) and a polyalkyleneimine, and an amorphous resin (A).

Binder resin composition for toner

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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Izumiotsu, Japan

Motomu Shibata