The Synthesis and Characterization of Highly Soluble Perylene Dyes for Digital Textile Printing
Digital textile printing (DTP) is a process of printing a pattern or image directly designed on a fabric by using an ink-jet injection method. The inks for DTP can be classified into a water-soluble ink and a solvent ink depending on the kinds of fibers used. Digital textile printing has many advantages as follows; firstly, it shortens the whole process time due to the elimination of screen plate manufacturing process. Secondly, it is an eco-friendly textile printing process that can reduce the environmental pollution such as waste-water. Finally, it is ideal for short runs, customized designs, and one of a kind prints. In this study, three scarlet acid dyes were designed and synthesized which have high color strength and color purity. The suitable ink formulation recipes were also studied in order to apply the synthesized dyes for high-speed DTP. The three scarlet acid dyes were modified from perylene precursors, respectively. The perylene dyes have high tinctorial strength and superior light/heat stability. In order to improve the low water solubility of perylene dyes, sulfonic acid groups were introduced at the bay positions of perylene moiety. In addition, the different functional groups were introduced at the terminal positions of the perylene moiety for improving the light fastness and the optical properties of the dyes. Consequently, the prepared scarlet inks with perylene dyes were successfully applied for DTP.