METHOD FOR PRODUCING BINDER RESIN FOR TONER

To provide a method for producing a binder resin for a toner which is excellent in hot offset resistance and low temperature fixability of a toner.SOLUTION: A method for producing a binder resin for a toner includes a step A of addition polymerizing an addition polymerizable monomer and an amphoteric reactive monomer in the presence of a polymer (A) having an unsaturated bond, and a step B of polycondensing a polycondensable monomer containing a carboxylic acid component and an alcohol component, in which the step A and the step B are carried out in the same reaction container, and a polycondensation-based resin segment and an addition polymerization-based resin segment are bonded to each other through the amphoteric reactive monomer, wherein a substance amount of a monomer having an unsaturated bond constituting the polymer (A) having the unsaturated bond is 5.0×10-5 mmol or more and 2.0×10-2 mmol or less with respect to 1 g of the total amount of the addition polymerizable monomer, the amphoteric reactive monomer and the polycondensable monomer.SELECTED DRAWING: None 【課題】トナーの耐ホットオフセット性と低温定着性に優れたトナー用結着樹脂の製造方法に関すること。【解決手段】不飽和結合を有する重合体（Ａ）の存在下で付加重合性モノマーと両反応性モノマーとを付加重合させる工程Ａ、並びにカルボン酸成分及びアルコール成分を含む重縮合性モノマーを重縮合させる工程Ｂを含み、該工程Ａと該工程Ｂを同一反応容器中で行う、重縮合系樹脂セグメントと付加重合系樹脂セグメントが両反応性モノマーを介して結合したトナー用結着樹脂の製造方法であって、前記不飽和結合を有する重合体（Ａ）を構成する不飽和結合を有する単量体の物質量が、付加重合性モノマー、両反応性モノマー及び重縮合性モノマーの合計量1gに対して5.0×10-5mmol以上2.0×10-2mmol以下である、トナー用結着樹脂の製造方法。【選択図】なし