Additives are mainly used to improve the performance of ink. Additives commonly used in UV ink include stabilizer, leveling agent, defoamer, dispersant, wax, etc.
(1) Stabilizer: stabilizer is used to reduce thermal polymerization during storage and improve the storage stability of ink. Hydroquinone, p-methoxyphenol, p-benzoquinone and 2,6-di-t-butyl cresol are commonly used.
(2) Leveling agent: leveling agent is used to improve the leveling of ink layer, prevent shrinkage, make the surface of ink film flat, and increase the gloss of ink printing.
(3) Defoamer: defoamer is used to improve the leveling of the ink layer, prevent the generation of shrinkage, smooth the surface of the ink film, and increase the gloss of ink printing.
(4) Dispersant: dispersant can make the pigment in the ink well and low wetted in the binder, make the pigment well dispersed in the ink, and shorten the grinding time during ink manufacturing; Reduce the oil absorption of pigment to produce high concentration ink; Prevent the aggregation and precipitation of pigment particles in ink. Dispersants are generally surfactants.
(5) Wax: the main function of wax is to change the rheology of ink, improve water resistance and printing performance (such as adjusting viscosity), reduce the disadvantages such as dirt and paper wool, form a smooth wax film on the surface of dried ink film, and improve the wear resistance of printed matter. In UV ink, wax also blocks air, reduces oxygen polymerization, and is conducive to surface curing. However, adding excessive wax and selecting the wrong wax in the ink will reduce the gloss of the ink, destroy the ink transfer performance and prolong the drying time.
