ELECTROSTATIC CHARGE IMAGE DEVELOPING TONER AND IMAGE FORMING METHOD

摘要

PURPOSE: To maintain a high developing property and high fluidity even for repetition of copying and to always obtain images of a high density without fog by adding a fluidizing agent and a ferroelectric fine powder produced by a hydrothermal synthesis method to color particles. CONSTITUTION: A ferroelectric fine powder comprising at least a resin and a coloring agent is added to the toner. The hydrothermal synthesis is such a method that two or more kinds of compds. such as soln. and solid metal salt contribute the reaction to proceed under hydrothermal conditions to synthesize a desired compd. The ferroelectric fine powder obtd. by this method has a sharper distribution of the grain size, lower aggregating property and uniform shapes of particles in cube or sphere compared to a ferroelectric fine powder obtd. by a pulverizing method or sintering method conventionally used for a developer. When the ferroelectric fine powder obtd. by the hydrothermal synthesis is added to color particles, the powder shows uniform state in the color particles and is present as the primary particles without aggregation since the powder has good dispersibility.