Synthesis Of Photoactive Resins Used In Water-borne UV Ink And Water-borne Macromolecular Photoinitiator

UV-radiation curing is found increasing applications in coatings, adhesives, printing ink, photo resists and biomaterials due to its rapid cure, solvent free characteristics, application versatility, low energy and low temperature operation. However, with the concern of health and the new requirement of packaging printing such as food, alcohol and tobacco, and toys, more and more people pay their attention to the strong irritant of the reactive diluents and the residues of photolysis fragments. The research of new water-borne UV ink which is environment-friendly becomes the most important mission during the development of modern packaging and printing industry.Nowadays, there are many problems in the traditional water-borne UV ink, such as the compatibility of the oligomers and photoinitiators as well as the residual, migration and toxicity of the small molecule photoinitiator. This has caused some limitations in the use of food and other packaging and printing materials which require a higher premium on health. In order to meet the needs of practical application and point the above problems, the synthesis of novel water-borne resins with photoinitiator groups on and water-borne macromolecular photoinitiators were studied in this paper.In the first part of this article, the principles of UV curing technology, characteristics and application were outlined. Furthermore, the composition of the water-borne UV system and the application of the water-borne UV ink were also introduced.In the second part, the novel water-borne epoxy acrylic resins with photoinitiator groups on were synthesized, and the structure of products were characterized by infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMP). The conditions of the reaction and the preliminary UV-curing behavior were also studied. The results showed that compared to the blending system, the UV-curing effect of the synthetic grafting system was better, curing coat performance was excellent and the thermal stability was improved. In addition, the resins were used in water-borne UV ink, and its essential function was studied. The results indicated that the ink could meet the basic requirements of environmental printing.In the last part, the water-borne macromolecular photoinitiators were designed and synthesized through the reaction of polyethylene glycol, dimethylol-propionic acid, 4-hydroxy benzophenone and toluene 2,4-diisocyanate which had two NCO. FTIR was used to characterize the structures of the products. The optimum synthesis conditions were researched by the NCO content of the products. In order to test its photo-initiation efficiency, the macromolecular photoinitiator was applied into water-borne epoxy acrylic resin. The research had shown that the curing coat performance was better compared with small molecule photoinitiator, and the only drawback was the curing rate should be further increased.