| 摘要 |
PURPOSE:To charge electrostatically the coating layer of a heat-roller fixing device to positive polarity which is the same as that of a positively charged toner so as to prevent electrostatic offsets stably and inexpensively, by using tetrafluoroethylene containing chromic acid for forming the coating layer. CONSTITUTION:A heat roller 1 contains a heater 3 at the inside of its body and is provided with a coating layer 5 on its core 4. A supporting body 8 holding positively charged toner 6 is passed through the space between the heat roller 1 and a press roller 2 and a toner image 7 is thermally fixed on the supporting body 8. Since the coating layer 5 of the heat roller 1 is usually provided on a fluorocarbon resin, the coating layer 5 is negatively charged as the fixing device is actually used. However, since the coating layer 5 of this inventions is formed of tetrafluoroethylene containing chromic acid as an additive, this coating layer 5 is charged to positive polarity which is the same as that of the toner 6 and electrostatic offsets can be prevented. |
