| 摘要 |
PURPOSE:To obtain colored polymer particles narrow in particle size distribution suitable for the toner of an electrophotographic developer by forming a colorant layer on the circumference of each core particle, and adding fine vinyl polymer particles to form an outermost shell composed of said fine particles. CONSTITUTION:The vinyl polymer particles as the core particles are formed from a main monomer or main monomers selected from aromatic vinyl compounds, acrylates and methacrylates by the emulsion polymerization, soap- free polymerization, seed polymerization, or nonaqueous system dispersion polymerization method, and it has an average particle diameter of 1-100mum, and the colorant is mixed with said polymer particles in a dry state to form the colorant layer, and further, the fine vinyl polymer particles having an average particle diameter of 0.01-1.0mum prepared from a main monomer or main monomers same as before by the same polymerization method except the seed polymerization method are added in a dry state to form the outermost shell composed of the fine polymer particles, thus permitting the obtained fine colored polymer particles to be narrow in particle size distribution, uniform in size, and almost spherical. |
