Toner for electrostatic image development and process for preparing the same
AssigneeSharp Kabushiki Kaisha
InventorTakanori Kamoto
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Abstract
A process for preparing a toner for electrostatic image development, the process comprising the steps of: (S1) mixing an aqueous pigment dispersion and an aqueous resin particle dispersion containing self-dispersible polyester resin particles as a binder resin to prepare a mixture; and (S2) adding a polyvalent metal salt as a flocculant to the mixture while stirring to form aggregates of the pigment bonded to the resin particles, wherein the self-dispersible polyester resin is prepared by reacting a carboxylic acid compound with an alcohol compound inclusive of a polyhydric alcohol, the carboxylic acid compound being one or more of a polycarboxylic acid having three or more carboxyl groups and its anhydride.
Claims17
A process for preparing a toner for electrostatic image development, the process comprising the steps of:
- (S1) preparing an aqueous resin particle dispersion containing self-dispersible polyester resin particles as a binder resin but not containing a surfactant, and then mixing an aqueous pigment dispersion and the aqueous resin particle dispersion to prepare a mixture;
- and
- (S2) adding a polyvalent metal salt as a flocculant to the mixture while stirring to form aggregates of the pigment bonded to the resin particles,
- wherein the self-dispersible polyester resin is prepared by reacting a carboxylic acid compound with an alcohol compound inclusive of a polyhydric alcohol, and additionally introducing polyfunctional carboxylic acids into a reaction system of the self-dispersible polyester resin in a terminal period of polymerization of said carboxylic acid compound with said alcohol compound, the carboxylic acid compound being one or more of a polycarboxylic acid having three or more carboxyl groups and its anhydride,
- said self-dispersible polyester resin having in its main chain a carboxyl group or carboxylic salt as a hydrophilic group.
Dependencies are inferred from the claim text.