Waterborne UV coatings mainly include Waterborne UV resins, photoinitiators, additives and coloring coatings. Among all the components, the Waterborne UV resin has the greatest impact on the performance of Waterborne UV coating. The performance of Waterborne UV resin affects the strength, corrosion resistance and curing sensitivity of the cured film on the surface of the coating [1]. The water-based resin is also affected by photoinitiator. Under the influence of photoinitiator, the water-based resin can be cured under light. Therefore, photoinitiator is also an important part of Waterborne UV coatings. The future development demand of photoinitiator is polymerizable and macromolecular.
Advantages of Waterborne UV coatings: the viscosity of coatings can be adjusted without diluting monomers, eliminating the toxicity and irritation of traditional coatings. Rheological additives can be properly added to reduce the viscosity of the coating system, which is convenient for the coating process. When the coating is made of plastic and other materials, water can be used as diluent to improve the adhesion between the coating and the coating. It improves the dust-proof and scratch proof ability of the coating before curing, improves the finish of the coating, and the cured film is ultra-thin. Coating equipment is easy to clean. Waterborne UVB coatings have good flame retardancy. Since no low molecular active diluent is used, flexibility and hardness can be considered.
Waterborne UV resin coatings can be crosslinked and cured rapidly under the action of photoinitiator and ultraviolet light. The biggest advantage of waterborne resin is controllable viscosity, clean, environmental protection, energy saving and high efficiency, and the chemical structure of prepolymer can be designed according to actual needs. However, there are still some deficiencies in this system, such as the long-term stability of the coating water dispersion system needs to be improved, and the water absorption of the cured film needs to be improved. Some scholars pointed out that in the future, waterborne light curing technology will develop in the following aspects.
(1) Preparation of new oligomers: including low viscosity, high activity, high solid content, multifunctional and hyperbranched.
(2) Develop new active diluents: including new acrylate active diluents, which have high conversion, high reactivity and low volume shrinkage.
(3) Research on new curing systems: in order to overcome the defects of incomplete curing sometimes caused by limited UV penetration, dual curing systems are adopted, such as free radical light curing / cationic light curing, free radical light curing, thermal curing, free radical light curing / anaerobic curing, free radical light curing / wet curing, free radical light curing / redox curing, so as to give full play to the synergy between the two, Promote the further development of the application field of waterborne light curing materials.
Post time: May-25-2022
