Patent ID: 8852842

Claim:
A production process of a toner composed of colored resin particles, comprising Step 1 of preparing an aqueous dispersion containing colored resin particles formed by a wet process; Step 2 of washing the colored resin particles with water; Filtration Step 3 of separating the colored resin particles by filtration to obtain wet colored resin particles; and Drying Step 4 of drying the wet colored resin particles, wherein in Drying Step 4, (a) the wet colored resin particles are poured into a rotary vane type agitating device having an agitation vessel, a rotating drive shaft and an agitating vane and having a structure that the agitating vane fixed to the rotating drive shaft extending through a bottom wall of the agitation vessel is arranged at a bottom of the agitation vessel, and two gas inlet ports are arranged in opposition to each other at lower portions of the agitation vessel, and at least one gas outlet port is arranged at an upper portion of the agitation vessel, wherein the gas inlet ports are opened on the side upper than the position of the agitating vane and at upper portions of the lower half of the peripheral wall portion of the agitation vessel, and a main axis of a gas inlet line communicating with each of the gas inlet ports is set to an angle within a range from 0 to 30° with a tangential direction to an inner peripheral surface of the agitation vessel, (b) the wet colored resin particles are dried by a method, in which the wet colored resin particles are agitated by the rotary vane within the agitation vessel while supplying a heated gas from the gas inlet ports, thereby forming a fluidized bed of the wet colored resin particles, and a mixed gas containing the heated gas supplied and water volatilized out of the wet colored resin particles is discharged from the gas outlet port to the outside, and (c) the temperature of the heated gas introduced from each of the gas inlet ports is controlled to a temperature within a range from the glass transition temperature of the binder resin component making up the colored resin particles to a temperature higher by 50° C. than the glass transition temperature to start drying, and then at the point of time the relative humidity of the mixed gas discharged from the gas outlet port has reached 40 to 80%, the temperature of the heated gas introduced from each of the gas inlet ports is lowered to a temperature within a range from a temperature lower by 20° C. than the glass transition temperature to the glass transition temperature to continue the drying, and drying conditions are controlled in such a manner that the temperature of the mixed gas discharged from the gas outlet port falls within a range from 20 to 60° C.