| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a toner with narrow distribution of particle size which does not cause offset development or contamination on a photoreceptor or rolls and which has excellent transfer property to paper, and to obtain an image of good image quality by melting and kneading a source material containing a coloring agent, binder resin, release agent and emulsification assistant and then mixing an aq. medium to emulsify. SOLUTION: A source mixture containing a coloring agent, binder resin, release agent, emulsification assistant and various compounding agent compounded if necessary is supplied to an extruding machine to be fused and kneaded, while the mixture is further mixed with an aq. medium and emulsified to produce an aq. dispersion containing color resin fine particles. Then the aq. medium is dried to obtain a thermal fixing type electrophotographic toner consisting of color resin fine particles. The compounding ratio of the source mixture is, by weight ratio, emulsification assistant/ release agent/binder resin/coloring agent=(1 to 80)/(1 to 20)/100/(1 to 20). The ratio of binder resin/(emulsification assistant+release agent) is 100/(2 to 100). Thus, the obtd. toner is excellent in low temp. fixing property, sharpness of an image and contamination resistance.</p> |
