Vegetable oils based UV-luminescent ink for screen printed anti-counterfeiting marking

Abstract

In this work, a new anti-counterfeiting feature relying on invisible fluorescent pattern printed with vegetable-oil-based inks were reported. Soybean oil (SBO) and tung oil (TO) were used as all the vehicle materials with low-cost, VOC-free and renewable characteristics, and grinding with ultraviolet luminescent pigment and specific additives to obtain the synthesized ink. A series of physical properties of the inks with different mixing ratios were investigated. It was found that the formulations of 75 wt.% vehicles, 15 wt.% fluorescent pigments, 3 wt.% fluorescent whitening agents, 2 wt.% ink driers, 2 wt.% defoaming agents, 2 wt.% dispersing agents, and 1 wt.% antioxidants (BHT) showed highly performance on the stability, dryness, acid and alkali resistance. More importantly, the desired-viscosity (3000 ∼ 4000 mPa·s) inks were applied on the coated paper to obtain invisible geometric designs by screen printing technology, which showed bright blue fluorescence under 365 nm UV-light irradiation. Therefore, by applying the vegetable-oil-based ink in fluorescent security marking, the information in images could be protected in such a simple and green way that was convenient to observe and verify. It exhibited the wide potentials on the anti-counterfeiting printing and commodity packaging.