Photopolymerization and Adhesion Properties of UV Curable Jet Ink

Abstract

Ink-jet technology has been used for not only printing industry but also printable electronics and other applications. The advantages of UV ink-jet are rapid curing, no-VOC, and adhesion on non-porous substrates, and UV ink-jet is one of current trends in industrial ink-jet market. In this paper, the fundamental formula of free-radical type UV curable ink-jet ink without solvent was discussed from a viewpoint of chemical structure of monomers. The relationship between these formulas and the adhesion property on plastic substrate such as PET and PVC was also investigated. As result, UV curable jet ink formulated by flexible monomers showed higher conversion of acryloyl group, but the relations between conversion and adhesion was not found. The adhesion property of UV ink was greatly depended on the difference of surface energy between plastic substrate and ink itself. The ink with our trial formula could be used in piezoelectric printer head with increasing internal temperature of the head around 35-40°C.