| 摘要 |
PURPOSE:To obtain a toner giving high image density and having satisfactory fixability and superior developing properties by incorporating silica and a water soluble inorg. salt in an aqueous phase. CONSTITUTION:When a polymerizable monomer system is polymerized in an aqueous phase, silica and a water soluble inorg. salt are added to the aqueous phase. Sodium chloride, potassium chloride or other ordinary water soluble inorg. salt is used as the water soluble inorg. salt and the salt is added by 1/1,000-1/1, preferably 1/50-1/5 of the amount of the silica added as a dispersant. The silica used may be fine powder of positively chargeable hydrophilic silica such as colloidal silica as anionic silica or aminoalkyl modified colloidal silica as cationic silica. It is preferable that a polymerizable monomer system contg. a (co)polymer or cyclized rubber having polar groups is suspended and polymerized in an aqueous phase contg. a dispersed dispersant whose electrostatic chargeability is reverse to that of the polar polymer. |
