Abstract: Disclosed herein are non-aqueous, radiation curable inkjet inks exhibiting stability at high shear rate (good rheological stability), stability at high temperatures, and/or stability in inkjet print heads, especially impulse inkjet print heads. The inks have a wide process window at a variety of print speeds using an impulse inkjet print head.

Abstract: Disclosed herein are rapid radiation curable ink compositions that can cure at speeds that are greater than the speeds at which other commercially available ink compositions cure. The rapidly curing ink compositions advantageously display an increased cure speed, improved adhesion and solvent resistance when compared with other commercially available compositions. The ink compositions of the invention are substantially free of solvent, and include an ethylenically unsaturated hyperbranched oligomer having an average functionality of at least 6 per oligomer, a difunctional ethylenically unsaturated compound, and a photoinitiator. The ink compositions optionally include a surfactant and/or a vinyl amide monomer.