TONER AND PRODUCTION THEREOF

摘要

PURPOSE:To obtain a toner having satisfactory fixability at low temp. or under low pressure by allowing a vinyl polymer to exist as spherical bodies in soft toner particles and forming films of a vinyl polymer as the shells of the particles. CONSTITUTION:An aq. dispersion liq. contg. toner particles based on a soft component is mixed with an aq. suspension or emulsion of a vinyl monomer contg. an oil soluble initiator, the particles are swollen with the vinyl monomer and the mixture is heated to the decomposition temp. of the initiator or above. A vinyl monomer is suspended in water as particles having a smaller average particle size than the swollen particles, the resulting aq. suspension is continuously added and polymn. is allowed to proceed to form shells. Styrene resin or acrylic resin may be used as the soft component forming the cores. The vinyl monomer as the precursor of a vinyl polymer forming the shells may be a styrene monomer or a vinyl deriv. such as acrylic acid.