| 摘要 |
PURPOSE:To improve resolving power, to permit developing with low potential and to improve durability with respect to a toner used for screen process by making the shape of the toner spherical and treatig the surface with surfactants of alkyl ester type. CONSTITUTION:Styrene butyl methacrylate and styrene dimethyl amino ethyl methacrylate are used as a binder resin, and carbon black, and oil black HBB are ised as coloring agents. Polyoxy-ethylene stearyl ester which is a surfactant of alkyl etster type is added thereto, and the mixture is dispersed and dissolved in a solvent such as MEK; thereafter, the soln. is sprayed and dried, whereby a toner for screen process is obtained. Such toner and carrier iron particles are mixed to form a developer. When 100,000 sheets are copied continuously with a dry type electrophotographic copier by using such developer, the pictures that permits development with low potential having high resolving power are obtained. |
