NEGATIVELY-CHARGED TONER FOR ELECTROSTATIC CHARGE IMAGE DEVELOPMENT

PROBLEM TO BE SOLVED: To provide a negatively-charged toner for electrostatic charge image development that can achieve both low-temperature fixability and blocking resistance, and is excellent in image quality.SOLUTION: The most effective form for achieving both low-temperature fixability and blocking resistance is a form in which shell particles are thinly coated on the surface of each of core particles having low-temperature fixability at high coverage and are easily retained on the surface of each of the core particles. A negatively-charged toner for electrostatic charge image development is obtained by forming an intermediate layer having the polarity reverse to that of the core particles on the surface of each of the core particles in an aqueous medium, and causing the shell particles having the reverse polarity to that of the intermediate layer and containing at least a binder resin to be adhered to the surface of the intermediate layer to form a shell layer. 【課題】低温定着性と耐ブロッキング性を両立でき、画質に優れた静電荷像現像用負帯電トナーを提供することを課題とする。【解決手段】低温定着性と耐ブロッキング性を両立するために最も効果的な形態とは、シェル粒子が、低温定着性を有するコア粒子の表面に、高い被覆率で、薄く被覆されており、しかもコア粒子表面に留まりやすい形態である。コア粒子の表面に、水系媒体中でコア粒子と逆極性を有する中間層を形成し、次いで中間層の表面に中間層と逆極性を有し、少なくとも結着樹脂を含有するシェル粒子を付着させてシェル層を形成してなる静電荷像現像用負帯電トナーにより解決する。【選択図】なし