Hideyuki Akagi

Effects of toner charge, size, and surface structure on its adhesion forces

Recent needs of higher copy quality with dry xerography led to aggressive pursuit of smaller particle size toners also in the toner technology areas. This is based on a belief that copy quality will be improved as the toner particle size is reduced. On the other hand, the toner size reduction has been known to cause difficulties in the xerographic process, such as poor transfer properties, for example. The development and transfer steps in the xerographic system depend on detachment of charged toner particles by the electric field which has to overcome the adhesion force to carrier beads and the photoreceptor. In order to find small toner particles matching the xerographic process, understanding of adhesion forces of charged toner particles is necessary. We have evaluated the detachment field of charged toner particles varying the size, composition materials, and surface structure. The results showed that the detachment field was dominated by the electrostatic force which in turn depended on the toner surface roughness. This roughness can be related to the actual contact area with the substrate surface. Seven micrometers toners designed according to the above findings gave good transfer properties.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.