Patent ID: 11932770

Abstract:
A method for producing a resin sintered body 1 by applying an ink 3 to thermoplastic resin powder 2 and sintering the powder, the method including the step of immersing an intermediate resin sintered body 1m, which has an unevenly colored region on the surface thereof and the whole of which has been already sintered, in a surface treatment liquid containing sulfuric acid and chromic anhydride, in which the concentration of chromic anhydride is 300 g/L or more, for 5 minutes or longer. When producing a resin sintered body by sintering thermoplastic resin powder, the surface of the resin sintered body can be evenly and sufficiently colored to an extent required without an unevenly colored region on the surface thereof, and also the surface of the resin sintered body can have a good appearance and smoothness.