| 摘要 |
PURPOSE:To obtain a developer capable of preventing offset and being fixed at low fixing temperature by using a specified polyester resin and at least 2 kinds of electric charge controllers as essential components. CONSTITUTION:The polyester to be used as the main component of the binder resin is obtained by polycondensing at least (A) a diol component represented by formula I in which R is ethylene or propylene and each of x and y is an integer and an average value of x+y is 2-7, (B) another diol component represented by formula II in which n is an integer of 2-6, (C) a divalent carboxylic acid or its anhydride or its lower alkyl ester, and (D) a trivalent or higher polyvalent carboxylic acid or its anhydride or its lower alkyl ester in an A:B:C+D molar proportion of 10-30:10-25:2.5-15mol.% of the total polyester constituents, and the toner contains at least 2 kinds of charge controllers. |
