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Purpose The purpose of this paper is to prepare ultra-violet (UV)-curable inkjet inks for textile printing application. The influence of both type and component ratio of monomer/oligomer on the quality of the desired viscosity range is studied. Moreover, the effect of pigment/resin ratio on the rheological behaviour of the ink has been studied. Design/methodology/approach Aqueous dispersions of nanoscale organic pigments were prepared through ball milling and ultrasonication. The dispersed pigments were encapsulated into UV-curable resin via miniemulsion technique, using different types and component ratios of monomers and oligomers. Findings It was found that the monomer/oligomer ratio of 2:3 and the pigment/resin ratio of 2:1 gave the most stable miniemulsion dispersions and provided the most suitable rheological range for inkjet printing inks. Research limitations/implications As the rheology of the ink is optimised, most of the problems associated with the jetting process could be avoided. Practical implications This method of using UV-curable encapsulated inks eliminates the usage of binders, which are the principal factor for nozzle clogging of the print head. In addition, binders are responsible for the coarse handle of the printed textiles. Social implications The UV-curable inks were viewed as a green technology by the US Environmental Protection Agency. Originality/value This method is simple and fast and requires low cost. In addition, it could find numerous applications in surface coating.

Different mini emulsion polymerizations were carried out with the combination of different concentration of anionic surfactant such as sodium dodecyl sulfate (SDS) or hydrophobic alkane such as (hexadecane), and/or different monomer ratios. The best comonomers composition that would lead to the best polymer latex properties to obtain nanoscale polymer latexes was studied. The polymer latexes in a size range between 156 and 65 nm by varying the SDS concentrations from 2 to 6 wt % were obtained, and also the particle size of the obtained polymer latexes decreases with the increases of hexadecane (HD) concentrations, and the best result was obtained with 4 wt % of a hexadecane. The best polymer latex properties in terms of particle size and binder softness were found in the best monomer ratio of BA:MMA:MAA (17.5:1.5:1.5) as the solid content was adapted to be 20%. Higher K/S values and improved crocking fastness are obtained with printing pastes containing prepared binder.

Aqueous dispersions of nanoscale organic pigments were successfully prepared via ball milling and ultrasonication. The dispersed organic pigments were encapsulated into UV-curable resins via a miniemulsion technique. Critical factors that affected the dispersion and encapsulation stability were investigated. The encapsulated organic pigments were characterised with transmission electron microscopy, thermogravimetric analyses, Fourier Transform-infrared spectra and zeta potential. The results clarified that the type of dispersing agent plays an important role in achieving maximal dispersion stability. Encapsulated organic pigments showed greater dispersion stability, and better wettability than the original pigments. Polyester tetra-acrylate oligomer can stabilise the mini-emulsion from diffusion degradation and inhibit phase separation with time. 1,6-Hexandiol dimethacrylate was the monomer of choice for ink-jet printing inks. Furthermore, it was found that monomer/oligomer and pigment/resin ratios were more influential and needed to be optimised. Thermal analysis, ultracentrifuge sedimentation and morphologies provided supporting evidence for the encapsulation of organic pigments into UV-curable resins.