Modeling the effect of pigments and processing parameters in polymeric composite for printing ink application using the response surface methodology

Abstract Digital printing is currently in high demand. Toner is a powder mainly composed of polymer and colorant that are used as ink in digital printing. The provision of a suitable color printing depends on appropriate selection of colorants and production parameter capable of producing a thin layer on paper. In this study, for the first time, the production of color printing toners (cyan, magenta and yellow) via emulsion aggregation method was optimized through response surface methodology with considering the effect of colorant. Evaluations were made for the influence of the colorant and production parameters on toner characteristics using particle size analysis, scanning electron microscopy (SEM), calorimetry and differential scanning calorimetry (DSC). The optimization involved two factors (time and agitation speed) and three responses (particle size (μm), particle size distribution and colorimetric properties ( L *, a *, b *) for each colorant. The response surface results demonstrated that each colorant due to its physicochemical properties showed different behavior. The results also showed that changing production conditions, such as increasing time or agitation rate, separately could not produce high-quality color printing toner. Therefore, an optimum condition was determined for each colorant. Results demonstrated that increasing the polarity of a pigment produced better dispersion and lower particle size with narrower distribution, while changing a pigment's characteristics did not affect the toner shape or its thermal properties.