Continuous-Flow Synthesis of the Azo Pigment Yellow 14 Using a Three-Stream Micromixing Process

In this study, a continuous-flow synthesis of the azo pigment Yellow 14 protocol has been developed using a three-stream micromixing process. This method controlled the pH of the azo coupling reaction process accurately and conveniently. After the optimization of the reaction conditions, the pigment products had a high purity and a good chromatic light. Compared with the two-stream micromixing process, the purity of the pigment products synthesized by the three-stream micromixing process increased by 9.41%, and the color differences between pigment products and Yellow 14 standard decreased obviously. Furthermore, the transparency numbers of pigment products synthesized by the microreactor system increased by 93–99% compared with that of the Yellow 14 standard. For the chromatic light, the red and blue hues of the pigment products were more intense than those of the Yellow 14 standard. Overall, the three-stream micromixing process led to an improvement of the pigment products, and this method also has good potential in industrial applications.