Low Viscosity and Good Flow Ink Systems Developed with a Polyester Acrylate Oligomer and Low Skin Irritation Monomers
UV-curable ink formulators face many challenges, such as matching the rheology constraints of the printing process with the necessary pigment loading to achieve color density, sufficient cure speed, adhesion to a variety of substrates, intercoat adhesion and chemical resistance.
This article introduces CN-2200, a polyester acrylate oligomer that has superior flow at higher pigment loading levels than epoxy or urethane acrylate oligomers. Polyester acrylates are commonly used as vehicles of lithographic inks because of good hydrophobic–lipophillic balance. CN-2200 was specifically developed to overcome some of the ink-formulating challenges mentioned.
This article also discusses the rheological properties of inks or pigment dispersions such as viscosity and yield stress. The rheology of a final ink is determined by the conformation that the vehicle adapts to completely wet the pigment surface. Here, the interaction is explored by measuring the rheological properties of various pigments dispersed in CN-2200 with various monomers. The monomers evaluated are excellent replacements for trimethylolpropane triacrylate, which can be a skin irritant for some individuals.