The development trend of energy-saving and environmentally friendly UV inks

UV ink, also known as UV light-solid ink, is an energy-saving environmentally friendly printing ink that has developed rapidly in recent years. This ink is irradiated with ultraviolet rays to cause polymerization of the ink binder to be dried. It is free of volatile organic solvents and is solvent free. In order to eliminate the emission of solvent-based ink VOC and meet the strict requirements of air quality standards, the printing industry gradually adopts UV ink technology to print products, so UV inks can quickly occupy a place in the market.

At present, UV ink has become a more mature ink technology, and its pollutant emission is almost zero. In addition to solvent-free, UV inks also have the advantages of fast drying speed, poor paste, clear dots, bright and bright ink, excellent chemical resistance and low dosage. According to statistics, the annual output of UV ink is about 16,000 tons in Japan, about 18,000 tons in Europe, and about 19,000 tons in North America. It is also widely used in offset, flexo, gravure, screen printing and inkjet printing in China.

UV inks are also composed of colorants, binders, and auxiliary materials. However, the composition of the binder is different from the conventional solvent-based ink.

From the comparison of the composition of the UV ink and the solvent type ink, the UV ink which is instantaneously cured by the ultraviolet irradiation to generate a group reaction, and the conventional solvent type ink and the solvent which are dried by the oxidative polymerization reaction which is infiltrated into the paper by the solvent for several hours. Compared with the water-based ink which is dried by the evaporation of water and the penetration of paper, the other components are different except for the pigment. The main components of the binder are photoinitiators, prepolymers and reactive monomers. The curing mechanism of the UV ink is that the photoinitiator in the ink is directly affected by the ultraviolet light, and the initiator molecules are chemically rearranged to form a radical, which in turn initiates chain polymerization of the functional groups in the prepolymer and the reactive monomer. The reaction forms a linear polymer, causing the photochemical reaction product to undergo a photocrosslinking reaction between the polymer chains, converting the liquid component into a three-dimensional network solid polymer, and finally forming a hard ink film, which is a a way to dry instantly.