| 摘要 |
<p>PURPOSE:To improve fixability without degrading a flow property, without increasing the adhesive power on an electrostatic charge image carrying body and without degrading transferability by specifying the range of the return quantity in closed circuit pulverization. CONSTITUTION:The return quantity of the closed circuit pulverization of the toner produced by melting and kneading at least a resin, coloring agents and release agent and subjecting the mixture to closed circuit pulverization is specified to a 0.10 to 1.00 range and more particularly to 0.20 to 0.80 range. The coefft. of shape is preferably 0.25 to 0.38 and the amt. of the release agent existing on the toner surface is preferably 0.18 to 0.25. The return quantity refers to a ratio of the coarse powder quantity circulated as a return component to a pulverizing machine 2 with respect to the supply rate from a machine 1 for supplying raw materials to be pulverized at a fixed rate and is expressed by the return quantity=(coarse powder quantity to be circulated)/(supply rate of the raw materials to be pulverized). A styrene-acryl copolymer and polyester resin exhibit particularly excellent characteristics as the resin for the toner to be used in this embodiment.</p> |
