| 摘要 |
PURPOSE:To form high quality images of improved frictional chargeability by providing the 1st resin part contg. magnetic powder in toner particles and a resin part having the electrostatic chargeability of the polarity reversed from the 1st resin part without contg. magnetic powder and providing volume resistivity higher than specific values. CONSTITUTION:The composite sheet wherein a sheet 2 made by dispersing ferromagnetic powder in a styrene-acrylate resin or the like is laminated thereon with a resin sheet 3 provided with the electrostatic chargeability of the polarity reversed from that of the sheet by adding a suitable charge control agent such as nigrosine dye or the like to the same resin or a dissimilar resin or the same compsn. as that of the sheet 3 dissolved in a solvent is spray coated on the sheet 2 is made, and this is ground and classified, whereby the toner of >=10<11>OMEGA.cm volume resistivity having the resin part 2 and the resin part 3 is produced. This toner is electrostatically charged with the two parts of different polarities by mutual friction and sticks on latent images in the same polarity parts as those of the latent images. Since it has high insulation characteristic, it yields high quality images stably at all times irrespectively of the kinds of paper and atmospheric humidity. |
