Controlling the micro-structure of disperse water-based inks for ink-jet printing

The study aims to investigate the effect of additives (poly (vinyl pyrrolidone) PVP, glycerol, ethylene glycol) on the performances of disperse water-based inks for ink-jet printing and how such additives interact with water. This should help into design suitable inks for textile printing by ink-jet printing, in particular for synthetic fibers such as polyester fabrics. Thirteen kinds of inks were prepared, and the glycerol content was replaced by water and PVP (K15, K30, K60), and the solubility parameter of the additive was calculated by the group contribution method. Low field nuclear magnetic resonance (LF-NMR) reveals the existence of bound water, intra-microstructure water, and extra-microstructure water in the ink, and the intra-microstructure water is entrapped inside the micro-structure formed by additives, mainly due to the presence of PVP. The optimal ink (Y5K30) has a low linewidth relative change (0.4%) and excellent sharpness. The reason is the existence of microstructure in ink, which reduces the mobility of solvent in ink and the diffusion of ink on fabric. PVP and disperse dyes have a strong affinity and help to improve the color depth and color fastness of the fabric. •The interaction between additives and water in ink was confirmed.•The microstructure of PVP was observed by SEM.•LF-NMR was adopted to reveal the existing water state of ink.•The microstructure of ink can reduce ink mobility and improve printing sharpness.