In this study, a continuous-flow coupling reaction method has been developed for the synthesis of Pigment Red 146 (C.I. PR 146). A computational fluid dynamics simulation was used to evaluate the effects of the micromixer structures on the mixing process. After the optimization of the microreactor structures and the reaction conditions, the conversion of the coupling reaction reached more than 99% using a microsieve pore dispersion reactor (two microsieve pores arranged side by side) and a smaller particle size and narrower particle-size distribution were obtained than were obtained in conventional batch reactors. Furthermore, the lightness and the green and the blue hues of these pigment products were more intense than those of the C.I. PR 146 standard. The largest conformity of the hue of the pigment products compared with the C.I. PR 146 standard was obtained using a microsieve pore dispersion reactor under the optimized reaction conditions. Finally, a scaling-up study of the pigment synthesis process in the microreactor system was initially explored. In conclusion, the microreactor system led to an improvement of the pigment products, and this method has a good industrial value.

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