| 摘要 |
PURPOSE:To provide the toner for developing electrostatic charge images which maintains a specified image density and does not generate the contamination to copied images by coating the surface of a charge control agent with a conductive material having a specific volume resistivity. CONSTITUTION:Known charge control agents are used. The charge control agents for positive electrostatic charge include, for example, a nigrosine dye, quaternary ammonium salt, polyamine resin, etc. Azo dyes contg. metals, such as Cr, Co and Al, metal complex salts of alkyl salicylic acid, etc., are usable as the charge control agent for negative electrostatic charge. Metals and half metals having <=10<9>ohm.cm specific volume resistivity, the oxides and multi component oxides thereof and the combinations of various kinds thereof are usable as the conductive material with which the surface of above-mentioned charge control agent is coated. The conductive material is exemplified by carbon. oxides, such as titanium black, tin oxide and iron oxide, and metals, such as gold, copper, iron and aluminum. The developing system having high durability over a long period of time is obtd. if such toner is used. |
