| Ultraviolet curing powder coating is a new environmentally friendly paint which is no solvent, low energy consumption, low curing temperature, curing speed, high efficiency. The UV curing powder coating consolidated many advantages between traditional powder coatings and radiation curing technology is a forward-looking product of the paint industry.In this dissertation, a multifunctional epoxy acrylate was successfully synthesized by using bisphenol-A type epoxy resin 904,epichlorohydrin, acrylic acid ,tetramethyl ammonium chloride, tetrabutylammonium bromide and sodium hydroxide etal. The effect of reaction temperature and catalyst type on the synthesis of multifunctional epoxy acrylate was studied.Hyperbranched polyester were synthesized by three aminomethane and butadiene anhydride,then hyperbranched polyester and 2,4-toluene diisocyanate,hydroxyethyl acrylate were reacted to produce hyperbranched polyurethane under the solvent of N, N-dimethyl acetamide.The matrix resin of UV curing powder coatings which has low melting temperature, leveling, good storage stability was made by the two syntheticed resin in a certain proportion. So that the obtained UV curing powder coatings, melting temperature is furtherly reduced and curing time is shortened. thus it was possible for UV curing powder coatings to be coated on the heat-sensitive substrates.Infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy were studied on the multifunctional epoxy acrylate resin and the hyperbranched polyurethane, thus the chemical structures of them were confirmed. Different initiator and initiator system were studied to investigate different initiator and initiator of the trigger principle and the effect on the curing properties.The thermal stability of coating cured by different initiator was investigated by thermo-gravimetric analysis (TGA). It was found that photoinitiator TPO and TPO/651 trigger composite system cured coating exhibited better thermal stability. Their initial degradation temperature were 334℃and 328℃respectively.Orthogonal design were used to study the compositions of these UV curing powder coatings. All formula was melt flowing by infrared light and cured by ultraviolet. Flexibility, performance testing, film pencil hardness testing, impact testing and the coating adhesion detection testing were conducted on the coating curing performance analysis. Experiment with multi-index comprehensive evaluation method was used to score to get the basic prescriptions of UV curing powder coatings.Studying on physical and mechanical performances of the UV-curing powder coatings films and chemical environmental resistance of them, we discussed the industrialization outlook of the epoxy powder coatings.
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