| 摘要 |
PURPOSE:To decrease the variance of the specific charge of a toner and to obtain excellent printed image by dissolving a binder resin, coloring agent and charge control agent into a solvent to prepare a uniform soln., evaporating the solvent therefrom and pulverizing the resulted toner lump material to form pulverous powder. CONSTITUTION:91pts.wt. Epoxy resin as the binder resin, 3pts.wt. nigrosine dye as the charge control agent and 33pts.wt. carbon black as the coloring agent are added under stirring each slightly into the methyl ethyl ketone in a beaker and the mixture thereof is thoroughly stirred. The soln. of the resulted uniform compsn. is vacuum-dried at 50 deg.C to evaporate the entire solvent. The resulted black lump material is pulverized after cooling to obtain the toner compsn. having 5-20mu grain size. Such toner compsn. is mixed with iron powder as a carrier by which a developer having 4wt% toner concn. is obtd. The sharp printed image without fogging is thus stably obtd. |
