In recent years, the development speed of UV ink technology at home and abroad is very fast, mainly reflected in the following points.
1. Cationic light curing system UV ink
Cationic light-curing system UV inks are currently the focus of research because the system UV inks have the following advantages.
(1) It is not inhibited by oxygen, which is conducive to highly cross-linked ink surface, making the coating tough and shiny. The free radical light curing system ink is severely inhibited by oxygen.
(2) The cationic UV curing ink does not generate unpleasant odor after curing, and once cations are formed upon irradiation with UV light, the curing reaction can be continued after stopping the light, which is beneficial to the deep curing and deep ink of the thick ink layer. Curing, which is difficult for free radical photocuring systems to achieve.
(3) The cationic UV curable UV ink has a small volume shrinkage (usually 3% to 5%) after curing, which is beneficial for improving the adhesion to the substrate. Free radical photocurable inks usually shrink by 10% after curing, which greatly affects the adhesiveness of the substrate.
Therefore, the use of cationic light curing system UV ink or free radical/cationic composite light curing system UV ink can increase the speed of light curing, especially for the curing of colored UV inks and screen printing UV inks with thick ink film. For the benefit.
The market growth rate of the cationic curing material is higher than the overall growth rate of the UV curing market. It can be seen that the UV ink using the cationic light curing system or the radical/cationic composite light curing system will be the new direction of UV ink development.
2. Water-based UV ink
Water-based UV inks, in addition to the characteristics of UV inks that are less polluting on the environment, have lower viscosity and rheological properties, and have a certain mitigating effect on oxygen inhibition. It solves some technical problems that early solventless UV inks cannot apply in gravure printing and flexo printing, and is suitable for gravure printing and flexographic printing.