UV curable coatings use ultraviolet light instead of heat to solidify the liquid coatings to the required solid coatings. With the new coating technology, coatings can go from a liquid form to a fully cured solid in few seconds while the traditional heat (ovens) cure may take minutes or hours.
Though the traditional coatings are still dominating the market and UV curable coatings only account for a few percent of the total global market due to the high cost, UV coatings still exhibit many advantages over the conventional coatings such as speed of cure, chemically resistant finishes, and high productivity. And when it comes to the applications which require improved productivity or face environmental regulations, traditional products will not always be the best choices.
Currently, the radiation-cured coatings have been adopted in several specific areas and have already seen double digit growth in injeket and automotive interior applications. Though UV coatings have numerous benefits, they cannot be used in the areas which require low applicable viscosity due to the high viscosity of the oligomers in the coatings. In order to adjust the viscosity, monomers or solvent must be added, which may have odor, affect the curing effect or emit VOC to cause environmental problems.
With the rapid development of UV coatings in recent years, formulations that combine different properties keep coming out, one of them is the water-borne UV coatings. Water-borne UV coatings use water to adjust the viscosity which can be used in areas requiring low viscosity such as paper and wood surfaces. Water-borne UV curable coatings have combined the benefits of UV curable coatings and waterborne coatings, thus they have more advantages such as nonflammability, thinner cured films, less pollution, and easy cleaning for coating equipment. However, the use of water-borne UV curable coatings is also limited due to the water drying difficulties before the UV curing process. Water evaporation needs extra heat or energy which may result in lower productivity. Other difficulties may also include discoloration and yellowing of the waterborne UV-curable coatings.
Both the traditional UV cured coatings and the water-borne UV coatings have their own limitations, researchers in the coating industry are keeping studying and developing the technologies and formulations to improve the performance of the radcure coatings. Currently, water-borne UV coatings will be a better choice when compared to the high viscosity, high reactivity of the reactive diluent (monomers) or VOC (volatile organic compounds) emissions of the solvent used in UV cured coatings. Though adopted only in specific applications, the water-borne UV coatings, as the green coating products, will be a major direction of the coating industry and will have a promising future. Formulations and technologies will be studied to overcome the difficulties and restrictions.
For the existing water-borne UV coatings, there are number of suppliers offering raw materials. The resin, as the key component of the water-borne UV coating, is playing an utmost important role in the chemical and mechanical properties of the final coating such as stain resistance, scratch resistance, weatherability or soft touch feeling. Besides the resin, water-borne UV coatings also include photoinitiators, additives and fillers which are all necessary for the coating properties. If you are looking for quality raw materials for the radiation-cured coatings, visit here!