SUSPENSION POLYMERIZATION

摘要

PURPOSE:To obtain a polymer suitable for a toner for electrophotography by preparing a dispersion with a narrow particle size distribution composed of a monomer composition and an aqueous medium using a specified method, subsequently polymerizing the resultant dispersion in a polymerization tank so that the particle size distribution of the resultant polymer may be readily controlled. CONSTITUTION:A continuous phase component composed of an aqueous medium and a dispersed phase component composed of a monomer composition are initially accommodated in mutually separated tanks. A continuous phase tank 1 and a dispersed phase tank 2 and both components are then simultaneously and continuously supplied from the tanks 1 and 2 through respectively independent flow paths 8 and 9 to an equipment 5 for application of a shearing force. A dispersion containing droplets with a desired size is subsequently prepared by applying a shearing force thereto and the resultant dispersion is then introduced into a polymerization tank 3 to complete the polymerization. In addition, a suspension stabilizer such as PVA is preferably admixed in the continuous phase.