Patent ID: 8247153

Claim:
A process for producing resin microparticles (A) for a toner raw material comprising: melt-mixing a resin with water, wherein the water is present in an amount of from 5 mass % to 50 mass % based on the total amount of the resin and water, and carrying out phase inversion in one twin screw extruder so as to form an aqueous dispersed system from the extruder comprised of the resin microparticles, the resin microparticles (A) satisfying all of the following requirements (i) to (iii): requirement (i): A particle diameter of 50% volume (D50) satisfies the relationship 0.05 μm<D50<1 μm; requirement (ii): A particle diameter of 10% volume (D10) and a particle diameter of 90% volume (D90) satisfy the relationship D90/D10<7; and requirement (iii): The content of an organic solvent is not more than 70 ppm, wherein the resin is a polyester based resin (B1) having a sulfonic acid group.