| 摘要 |
PURPOSE:To obtain a transparent and satisfactory picture image by using a positively chargeable yellow developing agent constituted of a yellow toner consisting of a binder resin and a specified disazo pigment, and carrier particles having coated layer consisting primarily of a fluorinated vinylidene resin. CONSTITUTION:The title positively chargeable yellow developing agent is constituted of a yellow toner consisting of a disazo pigment expressed by the formula, and carrier particles having coated layer consisting primarily of a fluorinated vinylidene resin. Suitable binder resin is a sharp hot-melt resin having a lower melt-viscosity than conventional resin to be used for hot roll fixing, most pref. polyester resin, epoxy resin, styrene/acrylic copolymer resin, etc. The positively chargeable yellow developing agent provides superior picture quality such as picture image density, fog, gradation, as well as providing stable picture quality and amt. of electric charge even after repetitive use for copying, and has superior durability. Since the transparency of the picture image is also high, the developing agent is satisfactorily useable for copy or full color copy to transparent sheets of an overhead projector. |
