| 摘要 |
PURPOSE:To enhance color density of a copied image and its color reproducibility by dispersing fine organic polymer particles specified in particle diameter and high in softening point in the electrostatic charge image developing toner composed essentially of a thermoplastic resin and a colorant. CONSTITUTION:The toner is prepared by adding a black pigment or dye, such as carbon black, an N-aryl-acetoacetamide type yellow monoazo pigment, a blue type pigment or dye, such as copper phthalocyanine, a green pigment, such as phthalocyanine, or the like with a binder resin, such as polyvinyltoluene or poly-alpha-methylstyrene, heat melting and pulverizing them, and at that time, incorporating the fine particles of the organic polymer, such as cross-linked polystyrene or trimethylstyrene, having a softening point of >=145 deg.C and a particle diameter of <=0.5mum, thus permitting the fine particles to have a function of rubbing and finely pulverizing the colorant, accordingly, to uniformly disturb the colorant, on the other hand, chargeability to be as much as -18.8muC/g, almost not different from the initial stage even if 20,000 sheet is continuously copied. |
