| 摘要 |
PURPOSE:To obtain sharp images having a high density and good quality by first mixing a charge control agent with a 1st binder resin having a high mol. wt. in a 1st stage, then melting and kneading the same with a 2nd binder resin having a low mol. wt. together with a coloring agent and grinding the resulting mixture in a 2nd stage. CONSTITUTION:The charge control agent is first mixed with the 1st binder resin having the high mol. wt. in the 1st stage. This mixture is melted and kneaded with the 2nd binder resin of the relatively low mol. wt. and ground in the 2nd stage. The developer obtd. in such a manner has good electrostatic charge efficiency and a narrow charge distribution as the shielding effect of the charge control agent and the dislodgment of the charge control agent due to the coloring agent is prevented and the uniform dispersibility of the charge control agent is improved. The sharp images faithful to originals are obtd. in this way. |
